basin basement structures: Topics by Science.govSUMMARYUnderstanding the sedimentary thickness,structureand tectonics of the West Bengalbasinis attempted using pseudo 3-D configuration derived from the first arrival seismic refraction data. Velocity images of the West Bengalbasinare derived using traveltime tomography along four profiles. The models are assessed for their reliability through chi-squares estimates, rms residual, traveltime fit, rays traced through the models, and resolution by checkerboard tests. Tomographic images depict smooth velocity variations of Recent, Quaternary and Tertiary sediments of velocity 1.8-4.3 km/s deposited over the Rajmahal trap of 4.8 km/s velocity and thebasement(5.9 km/s) down to a maximum depth of 16 km. The present study indicates a south-easterly dip ofbasinas evidenced from the pseudo 3-D configuration. Thebasementdepth along the seismic profiles varies from 1 km to 16 km depending on its location in thebasin. It is shallow in the north & west and deep in the east & Canada Goose Amsterdam

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  1. Seismotectonics of Reelfoot rift basement structures

    SciTech Connect

    Dart, R.L.; Swolfs, H.S. )


    Contour maps of the Precambrian basement surface show major northwest-trending structural features within the boundaries of the northeast-oriented Reelfoot rift. These northwest-trending features, southeast of New Madrid, Missouri, consist of a trough flanked on the northeast by a 2-km-high ridge. These features correlate with similar features on an updated depth-to-magnetic basement map. The boundary between the trough and the ridge slopes gently to the southwest. The upward projection of this boundary into the overlying Paleozoic strata may be expressed on a structure-contour map of the Cambrian rocks. The vertical relief of this boundary on the younger datum is inferred to be about 1 km. This Precambrian trough-ridge structure may correlate with a southwest dipping, west-northwest-striking normal fault inferred by Schwalb (1982) to offset rocks of the Cambrian-Ordovician Knox Megagroup that subcrop at the Paleozoic surface. Schwalb (1982) inferred 1.22 km of vertical relief on this fault near the bootheel of Missouri. The nature and significance of this tectonic-structural boundary is unclear, but at the top of the Precambrian basement rocks, it coincides with the southwestern terminus of the New Madrid seismic zone (NMSZ) near the end of the Blytheville arch in northeastern Arkansas. Since the mid-1970's, when instrumental recording began, some of the earthquakes in the NMSZ having the largest magnitudes occurred in this area. The authors working hypothesis is that this trough-ridge structural boundary may concentrate stress and/or may be a barrier that defines the southwestern limit of the seismically active axial fault zone in the rift. Future study will concentrate on improving the understanding of the influence of rift-bounding faults on the lateral extent of this structure, as well as constructing a tectonic stress model of seismically active rift faults and this trough-ridge structure.

  2. Alpine tectonics of granites in basement of Ysyk-Köl Basin, northern Tien Shan

    NASA Astrophysics Data System (ADS)

    Leonov, M. G.; Przhiyalgovsky, E. S.; Lavrushina, E. V.; Poleshchuk, A. V.; Rybin, A. K.


    The Ysyk-Köl Basin filled with Lower Jurassic-Quaternary sedimentary rocks is the largest intermontane negative structural unit of the northern Tien Shan. The basement of this basin is composed of Precambrian-Paleozoic rocks, largely of Ordovician and Silurian granitoids exposed in mountain ranges of the basin framework and as separate anticlinal domes situated in areas occupied by the Mesozoic-Cenozoic sedimentary cover. The postmagmatic tectonic internalstructure of the Chonkurchak (Chunkurchak), Kyzyl-Choku, Kyzyl-Bulak, and Prishib massifs emplaced in the basement, as well as their relationships to the sedimentary cover, are described in the paper. The study was carried out using the morphostructural method, detailed geological mapping, structural kinematic analysis, and petrographic examination of rocks. The internalstructure of Paleozoic granites in the basement and indications of their 3D tectonic flow are characterized. It is shown that granites underwent 3D deformation after their emplacement in the consolidated crust, and this process had a substantial influence on tectonic processes at the plate and orogenic stages of regional evolution.

  3. Regional trends in radiogenic heat generation in the Precambrian basement of the Western Canadian Basin

    NASA Astrophysics Data System (ADS)

    Jones, F. W.; Majorowicz, J. A.

    Radiogenic heat generation values for 381 basement samples from 229 sites in the western Canadian basin exhibit a lognormal frequency distribution. The mean value = 2.06 (S.D. = 1.22) µWm-3 is larger than the radiogenic heat generation values reported for the shield in the Superior (ca. 1.2 µWm-3, Jessop and Lewis, 1978) and Churchill (ca. 0.7 µWm-3, Drury, 1985) provinces. When equal Log A contour intervals are used to map the basement heat generation, three large zones of relatively high heat generation are found. One coincides with the Peace River Arch basement structure and one with the Athabasca axis (Darnley, 1981). There is no apparent indication of increased heat flow through the Paleozoic formations associated with these two zones. The third zone, in southwestern Saskatchewan, coincides with a high heat flow zone in the Swift Current area. The lack of correlation between heat flow and heat generation in Alberta may be due to the disturbance to the heat flow in the Paleozoic formations by water motion, or may indicate that the heat is from uranium, thorium and potassium isotope enrichment near the basement surface rather than enrichment throughout the entire upper crust.

  4. Structural analysis of a fractured basement reservoir, central Yemen

    NASA Astrophysics Data System (ADS)

    Veeningen, Resi; Rice, Hugh; Schneider, Dave; Grasemann, Bernhard; Decker, Kurt


    The Pan-African Arabian-Nubian Shield (ANS), within which Yemen lies, formed as a result of Neoproterozoic collisional events between c. 870-550 Ma. Several subsequent phases of extension occurred, from the Mesozoic (due to the breakup of Gondwana) to the Recent (forming the Gulf of Aden and the Red Sea). These resulted in the formation of numerous horst- and-graben structures and the development of fractured basement reservoirs in the southeast part of the ANS. Two drill cores from the Mesozoic Marib-Shabwa Basin, central Yemen, penetrated the upper part of the Pan-African basement. The cores show both a lithological and structural inhomogeneity, with variations in extension-related deformation structures such as dilatational breccias, open fractures and closed veins. At least three deformation events have been recognized: D1) Ductile to brittle NW-SE directed faulting during cooling of a granitic pluton. U-Pb zircon ages revealed an upper age limit for granite emplacement at 627±3.5 Ma. As these structures show evidence for ductile deformation, this event must have occurred during the Ediacaran, shortly after intrusion, since Rb/Sr and (U-Th)/He analyses show that subsequent re-heating of the basement did not take place. D2) The development of shallow dipping, NNE-SSW striking extensional faults that formed during the Upper Jurassic, simultaneously with the formation of the Marib-Shabwa Basin. These fractures are regularly cross-cut by D3. D3) Steeply dipping NNE-SSW to ENE-WSW veins that are consistent with the orientation of the opening of the Gulf of Aden. These faults are the youngest structures recognized. The formation of ductile to brittle faults in the granite (D1) resulted in a hydrothermally altered zone ca. 30 cm wide replacing (mainly) plagioclase with predominantly chlorite, as well as kaolinite and heavy element minerals such as pyrite. The alteration- induced porosity has an average value of 20%, indicating that the altered zone is potentially a

  5. Basement structure and its influence on the structural configuration of the northern North Sea rift

    NASA Astrophysics Data System (ADS)

    Fazlikhani, Hamed; Fossen, Haakon; Gawthorpe, Robert L.; Faleide, Jan Inge; Bell, Rebecca E.


    The northern North Sea rift basin developed on a heterogeneous crust comprising structures inherited from the Caledonian orogeny and Devonian postorogenic extension. Integrating two-dimensional regional seismic reflection data and information from basement wells, we investigate the prerift structural configuration in the northern North Sea rift. Three seismic facies have been defined below the base rift surface: (1) relatively low-amplitude and low-frequency reflections, interpreted as pre-Caledonian metasediments, Caledonian nappes, and/or Devonian clastic sediments; (2) packages of high-amplitude dipping reflections (>500 ms thick), interpreted as basement shear zones; and (3) medium-amplitude and high-frequency reflections interpreted as less sheared crystalline basement of Proterozoic and Paleozoic (Caledonian) origin. Some zones of Seismic Facies 2 can be linked to onshore Devonian shear zones, whereas others are restricted to the offshore rift area. Interpreted offshore shear zones dip S, ESE, and WNW in contrast to W to NW dipping shear zones onshore West Norway. Our results indicate that Devonian strain and ductile deformation was distributed throughout the Caledonian orogenic belt from central South Norway to the Shetland Platform. Most of the Devonian basins related to this extension are, however, removed by erosion during subsequent exhumation. Basement shear zones reactivated during the rifting and locally control the location and geometry of rift depocenters, e.g., in the Stord and East Shetland basins. Prerift structures with present-day dips >15° were reactivated, although some of the basement shear zones are displaced by rift faults regardless of their orientation relative to rift extension direction.

  6. Contour mapping of relic structures in the Precambrian basement of the Reelfoot rift, North American midcontinent

    USGS Publications Warehouse

    Dart, R.L.; Swolfs, H.S.


    A new contour map of the basement of the Reelfoot rift constructed from drill hole and seismic reflection data shows the general surface configuration as well as several major and minor structural features. The major features are two asymmetric intrarift basins, bounded by three structural highs, and the rift margins. The basins are oriented normal to the northeast trend of the rift. Two of the highs appear to be ridges of undetermined width that extend across the rift. The third high is an isolated dome or platform located between the basins. The minor features are three linear structures of low relief oriented subparallel to the trend of the rift. Two of these, located within the rift basins, may divide the rift basins into paired subbasins. These mapped features may be the remnants of initial extensional rifting, half graben faulting, and basement subsidence. The rift basins are interpreted as having formed as opposing half graben, and the structural highs are interpreted as having formed as associated accommodation zones. Some of these features appear to be reactivated seismogenic structures within the modem midcontinent compressional stress regime. A detailed knowledge of the geometries of the Reelfoot rift's basement features, therefore, is essential when evaluating their seismic risk potential.

  7. Basement and cover-rock deformation during Laramide contraction in the northern Madison Range (Montana) and its influence on Cenozoic basin formation

    USGS Publications Warehouse

    Kellogg, K.S.; Schmidt, C.J.; Young, S.W.


    Two major Laramide fault systems converge in the northwestern Madison Range: the northwest-striking, southwest-vergent Spanish Peaks reverse fault and the north-striking, east-vergent Hilgard thrust system. Analysis of foliation attitudes in basement gneiss north and south of the Spanish Peaks fault indicates that the basement in thrusted blocks of the Hilgard thrust system have been rotated by an amount similar to that of the basement-cover contact. Steeply dipping, north-striking breccia zones enclosing domains of relatively undeformed basement may have permitted domino-style rotation of basement blocks during simple shear between pairs of thrusts. No hydrocarbon discoveries have been made in this unique structural province. However, petroleum exploration here has focused on basement-cored anticlines, both surface and subthrust, related to the two major Laramide fault systems and on the fault-bounded blocks of Tertiary rocks within the post-Laramide extensional basins. -from Authors

  8. Rift architecture and evolution: The Sirt Basin, Libya: The influence of basement fabrics and oblique tectonics

    NASA Astrophysics Data System (ADS)

    Abdunaser, K. M.; McCaffrey, K. J. W.


    The Cretaceous-Tertiary northwest-trending Sirt Basin system, Libya, is a rift/sag basin formed on Pan-African to Paleozoic-aged basement of North Africa. In this study, we investigate the rift-basin architecture and tectonic framework of the western Sirt Basin. Using remote sensed data, supported by borehole data from about 300 deep wells and surface geologic maps, we constructed geological cross sections and surface geology maps. Indication of the relative timing of structures and movement along faults has been determined where possible. Direction statistics for all the interpreted linear features acquired in the study area were calculated and given as a total distribution and then the totals are broken down by the major basin elements of the area. Hundreds of lineaments were recognized. Their lengths, range between a hundred meters up to hundreds of kilometers and the longest of the dominant trends are between N35W-N55W and between N55E-N65E which coincides with Sirt Basin structures. The produced rose diagrams reveal that the majority of the surface linear features in the region have four preferred orientations: N40-50W in the Zallah Trough, N45-55W in the Dur al Abd Trough, N35-55W in the Az Zahrah-Al Hufrah Platform, and in contrast in the Waddan Uplift a N55-65E trend. We recognize six lithostratigraphic sequences (phases) in the area's stratigraphic framework. A Pre-graben (Pre-rift) initiation stage involved the Pre-Cretaceous sediments formed before the main Sirt Basin subsidence. Then followed a Cretaceous to Eocene graben-fill stage that can divided into four structurally-active and structurally-inactive periods, and finally a terminal continental siliciclastics-rich package representing the post-rift stage of the development in post-Eocene time. In general five major fault systems dissect and divide the study area into geomorphological elevated blocks and depressions. Most of the oil fields present in the study area are associated with structural hinge

  9. Two-stage formation model of the Junggar basin basement: Constraints to the growth style of Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    He, Dengfa


    Junggar Basin is located in the central part of the Central Asian Orogenic Belt (CAOB). Its basement nature is a highly controversial scientific topic, involving the basic style and processes of crustal growth. Some researchers considered the basement of the Junggar Basin as a Precambrian continental crust, which is not consistent with the petrological compositions of the adjacent orogenic belts and the crust isotopic compositions revealed by the volcanic rocks in the basin. Others, on the contrary, proposed an oceanic crust basement model that does not match with the crustal thickness and geophysical characteristics of the Junggar area. Additionally, there are several viewponits, such as the duplex basement with the underlying Precambrian crystalline rocks and the overlying pre-Carboniferous folded basement, and the collaged basement by the Precambrian micro-continent block in the central part and the Hercynian accretionary folded belts circling it. Anyway, it is necessary to explain the property of basement rock, its strong inhomogeneous compositions as well as the geophysical features. In this paper, based on the borehole data from more than 300 industry wells drilled into the Carboniferous System, together with the high-resolution gravity and magnetic data (in a scale of 1:50,000), we made a detailed analysis of the basement structure, formation timing and processes and its later evolution on a basis of core geochemical and isotopic analysis. Firstly, we defined the Mahu Pre-Cambrian micro-continental block in the juvenile crust of Junggar Basin according to the Hf isotopic analysis of the Carboniferous volcanic rocks. Secondly, the results of the tectonic setting and basin analysis suggest that the Junggar area incorporates three approximately E-W trending island arc belts (from north to south: Yemaquan- Wulungu-Chingiz, Jiangjunmiao-Luliang-Darbut and Zhongguai-Mosuowan- Baijiahai-Qitai island arcs respectively) and intervened three approximately E-W trending

  10. Effect of brown spider venom on basement membrane structures.


    Veiga, S S; Feitosa, L; dos Santos, V L; de Souza, G A; Ribeiro, A S; Mangili, O C; Porcionatto, M A; Nader, H B; Dietrich, C P; Brentani, R R; Gremski, W


    Loxoscelism or necrotic arachnidism are terms used to describe lesions and reactions induced by bites (envenomation) from spiders of the genus Loxosceles. Envenomation has been reported to provoke dermonecrosis and haemorrhage at the bite site and haemolysis, disseminated intravascular coagulation and renal failure. The purpose of this work was to study the effect of the venom of the brown spider Loxosceles intermedia on basement membrane structures and on its major constituent molecules. Light microscopy observations showed that L. intermedia venom obtained through electric shock, which reproduces two major signals of Loxoscelism in the laboratory, exhibits activity toward basement membrane structures in mouse Engelbreth-Holm-Swarm (EHS) sarcoma. Basement degradation was seen by a reduced periodic acid-Schiff (PAS) and alcian blue staining as well as by a reduced immunostaining for laminin when compared to control experiments. Electron microscopy studies confirmed the above results, showing the action of the venom on EHS-basement membranes and demonstrating that these tissue structures are susceptible to the venom. Using purified components of the basement membrane, we determined through SDS-PAGE and agarose gel that the venom is not active toward laminin or type IV collagen, but is capable of cleaving entactin and endothelial heparan sulphate proteoglycan. In addition, when EHS tissue was incubated with venom we detected a release of laminin into the supernatant, corroborating the occurrence of some basement membrane disruption. The venom-degrading effect on entactin was blocked by 1, 10-phenanthroline, but not by other protease inhibitors such as PMSF, NEM or pepstatin-A. By using light microscopy associated with PAS staining we were able to identify that 1,10-phenanthroline also inhibits EHS-basement membrane disruption evoked by venom, corroborating that a metalloprotease of venom is involved in these effects. Degradation of these extracellular matrix

  11. Control of salt tectonics by young basement tectonics in Brazil`s offshore basins

    SciTech Connect

    Szatmari, P.; Mohriak, W.


    The Campos basin (offshore SE Brazil) is one of the most successful areas of oil exploration in South America. Discovered 20 years ago, its production (500,000 b/d) and reserves (2.9 billion barrels) are second only to Venezuela`s. This richness is due, to a large extent, to intense salt tectonics and the abundance of turbidites. Reactivated basement structures onshore provide a unique opportunity to understand the role of young basement tectonics in controlling salt tectonics and petroleum occurrence. The mountains of SE Brazil, over 1500 m high, formed by the reactivation of late Precambrian thrust and wrench zones under E-W compression, presumably caused by Mid-Atlantic ridge push. Coastal mountain ranges, up to 3000 m high, are limited to the segment of the Atlantic between the Vitoria-Trindade hotspot chain and the Rio Grande Rise. The coastal ranges formed as this segment of oceanic crust and adjacent continental margin were pushed WSW along a reactivated Precambrian wrench zone. To the north of this segment, salt tectonics is mostly due to basinward sliding on a tilted salt layer. Along the coastal ranges, to this is added basinward escape of the salt from beneath prograding sediments derived from the rising mountains. Extension above the salt tends to be compensated by compression farther basinward. Salt canopies, frequent in the Gulf of Mexico, occur only near the Abrolhos hotspot, where high temperatures during volcanic activity sharply reduced the viscosity of the salt.

  12. Basement configuration of the West Bengal sedimentary basin, India as revealed by seismic refraction tomography: its tectonic implications

    NASA Astrophysics Data System (ADS)

    Damodara, N.; Rao, V. Vijaya; Sain, Kalachand; Prasad, Asssrs; Murty, Asn


    SUMMARYUnderstanding the sedimentary thickness, <span class="hlt">structure</span> and tectonics of the West Bengal <span class="hlt">basin</span> is attempted using pseudo 3-D configuration derived from the first arrival seismic refraction data. Velocity images of the West Bengal <span class="hlt">basin</span> are derived using traveltime tomography along four profiles. The models are assessed for their reliability through chi-squares estimates, rms residual, traveltime fit, rays traced through the models, and resolution by checkerboard tests. Tomographic images depict smooth velocity variations of Recent, Quaternary and Tertiary sediments of velocity 1.8-4.3 km/s deposited over the Rajmahal trap of 4.8 km/s velocity and the <span class="hlt">basement</span> (5.9 km/s) down to a maximum depth of 16 km. The present study indicates a south-easterly dip of <span class="hlt">basin</span> as evidenced from the pseudo 3-D configuration. The <span class="hlt">basement</span> depth along the seismic profiles varies from 1 km to 16 km depending on its location in the <span class="hlt">basin</span>. It is shallow in the north & west and deep in the east & south. The depth of the <span class="hlt">basement</span> on the stable shelf of the <span class="hlt">basin</span> in the west gently increases to about 8 km and dips to a maximum depth of 16 km in the deep <span class="hlt">basin</span> part within a short distance in the east. The study identifies a regional feature, known as the Shelf break or the Hinge zone, where stable Indian shield ends and a sharp increase in sediment thickness occurs. The Hinge zone may represent the relict of continental and proto-oceanic crustal boundary formed during the rifting of India from Antarctica. The regional gravity map of the Bengal <span class="hlt">basin</span> prepared in this study clearly brings out the Hinge zone with a linear gravity high that is compatible with seismic data. Presence of Shelf break / Hinge zone and Rajmahal volcanism in the <span class="hlt">basin</span> suggests the influence of rifting of India from the combined Antarctica-Australia at ˜130 Ma due to mantle plume activity on the <span class="hlt">structure</span> and tectonics of the West Bengal <span class="hlt">basin</span>. These features along with the elevated rift shoulder are in</p> </li> <li> <p><span><span class="hlt">Basement</span> configuration of the West Bengal sedimentary <span class="hlt">basin</span>, India as revealed by seismic refraction tomography: its tectonic implications</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Damodara, N.; Rao, V. Vijaya; Sain, Kalachand; Prasad, A. S. S. S. R. S.; Murty, A. S. N.</p> <p>2017-03-01</p> <p>Understanding the sedimentary thickness, <span class="hlt">structure</span> and tectonics of the West Bengal <span class="hlt">basin</span> is attempted using pseudo 3-D configuration derived from the first arrival seismic refraction data. Velocity images of the West Bengal <span class="hlt">basin</span> are derived using traveltime tomography along four profiles. The models are assessed for their reliability through chi-squares estimates, rms residual, traveltime fit, rays traced through the models and resolution by checkerboard tests. Tomographic images depict smooth velocity variations of Recent, Quaternary and Tertiary sediments of velocity 1.8-4.3 km s-1 deposited over the Rajmahal trap of 4.8 km s-1 velocity and the <span class="hlt">basement</span> (5.9 km s-1) down to a maximum depth of 16 km. The present study indicates a south-easterly dip of <span class="hlt">basin</span> as evidenced from the pseudo 3-D configuration. The <span class="hlt">basement</span> depth along the seismic profiles varies from 1 to 16 km depending on its location in the <span class="hlt">basin</span>. It is shallow in the north & west and deep in the east & south. The depth of the <span class="hlt">basement</span> on the stable shelf of the <span class="hlt">basin</span> in the west gently increases to about 8 km and dips to a maximum depth of 16 km in the deep <span class="hlt">basin</span> part within a short distance in the east. The study identifies a regional feature, known as the Shelf break or the Hinge zone, where stable Indian shield ends and a sharp increase in sediment thickness occurs. The Hinge zone may represent the relict of continental and proto-oceanic crustal boundary formed during the rifting of India from Antarctica. The regional gravity map of the Bengal <span class="hlt">basin</span> prepared in this study clearly brings out the Hinge zone with a linear gravity high that is compatible with seismic data. Presence of Shelf break/Hinge zone and Rajmahal volcanism in the <span class="hlt">basin</span> suggests the influence of rifting of India from the combined Antarctica-Australia at ∼130 Ma due to mantle plume activity on the <span class="hlt">structure</span> and tectonics of the West Bengal <span class="hlt">basin</span>. These features along with the elevated rift shoulder are in agreement with the</p> </li> <li> <p><span>Percolation of diagenetic fluids in the Archaean <span class="hlt">basement</span> of the Franceville <span class="hlt">basin</span></span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Mouélé, Idalina Moubiya; Dudoignon, Patrick; Albani, Abderrazak El; Cuney, Michel; Boiron, Marie-Christine; Gauthier-Lafaye, François</p> <p>2014-01-01</p> <p>The Palaeoproterozoic Franceville <span class="hlt">basin</span>, Gabon, is mainly known for its high-grade uranium deposits, which are the only ones known to act as natural nuclear fission reactors. Previous work in the Kiéné region investigated the nature of the fluids responsible for these natural nuclear reactors. The present work focuses on the top of the Archaean granitic <span class="hlt">basement</span>, specifically, to identify and date the successive alteration events that affected this <span class="hlt">basement</span> just below the unconformity separating it from the Palaeoproterozoic <span class="hlt">basin</span>. Core from four drill holes crosscutting the <span class="hlt">basin-basement</span> unconformity have been studied. Dating is based on U-Pb isotopic analyses performed on monazite. The origin of fluids is discussed from the study of fluid inclusion planes (FIP) in quartz from <span class="hlt">basement</span> granitoids. From the deepest part of the drill holes to the unconformable boundary with the <span class="hlt">basin</span>, propylitic alteration assemblages are progressively replaced by illite and locally by a phengite + Fe chlorite ± Fe oxide assemblage. Illitic alteration is particularly strong along the sediment-granitoid contact and is associated with quartz dissolution. It was followed by calcite and anhydrite precipitation as fracture fillings. U-Pb isotopic dating outlines three successive events: a 3.0-2.9-Ga primary magmatic event, a 2.6-Ga propylitic alteration and a late 1.9-Ga diagenetic event. Fluid inclusion microthermometry suggests the circulation of three types of fluids: (1) a Na-Ca-rich diagenetic brine, (2) a moderately saline (diagenetic + meteoric) fluid, and (3) a low-salinity fluid of probable meteoric origin. These fluids are oxquyzfe. <a href=""><strong>カナダガチョウジャケ</strong></a> similar to those previously identified within the overlying sedimentary rocks of the Franceville <span class="hlt">basin</span>. Overall, the data collected in this study show that the Proterozoic-Archaean unconformity has operated as a major flow corridor for fluids circulation, around 1.9 Ga. highly saline diagenetic brines; hydrocarbon-rich fluids derived from organic matter</p> </li> <li> <p><span><span class="hlt">Basement</span> <span class="hlt">structures</span> over Rio Grande Rise from gravity inversion</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Constantino, Renata; Hackspacker, Peter Christian; Anderson de Souza, Iata; Sousa Lima Costa, Iago</p> <p>2017-04-01</p> <p>In this study, we show that from satellite-derived gravity field, bathymetry and sediment thicknesses, it is possible to give a 3-D model of the <span class="hlt">basement</span> over oceanic areas, and for this purpose, we have chosen the Rio Grande Rise, in South Atlantic Ocean, to build a gravity-equivalent <span class="hlt">basement</span> topography. The advantages of the method applied in this study are manifold: does not depend directly on reflection seismic data; can be applied quickly and with fewer costs for acquiring and interpreting the data; and as the main result, presents the physical surface below the sedimentary layer, which may be different from the acoustic <span class="hlt">basement</span>. We evaluated the gravity effect of the sediments using the global sediment thickness model of NOAA, fitting a sediment compaction model to observed density values from Deep Sea Drilling Program (DSDP) reports. The Global Relief Model ETOPO1 and constraining data from seismic interpretation on crustal thickness are integrated in the gravity inversion procedure. The modeled Moho depth values vary between 6 to 27 km over the area, being thicker under the Rio Grande Rise and also in the direction of São Paulo Plateau. The inversion for the gravity-equivalent <span class="hlt">basement</span> topography is applied for a gravity residual data, which is free from the gravity effect of sediments and from the gravity effect of the estimated Moho interface. A description of the <span class="hlt">basement</span> depth over Rio Grande Rise area is unprecedented in the literature, however, our results could be compared to in situ data, provided by DSDP, and a small difference of only 9 m between our <span class="hlt">basement</span> depth and leg 516 F was found. Our model shows a rift crossing the entire Rio Grande Rise deeper than previously presented in literature, with depths up to 5 km in the East Rio Grande Rise (ERGR) and deeper in the West Rio Grande Rise (WRGR), reaching 6.4 km. We find several short-wavelengths <span class="hlt">structures</span> not present in the bathymetry data. Seamounts, guyots and fracture zones are much more</p> </li> <li> <p><span><span class="hlt">Structural</span> Model of the <span class="hlt">Basement</span> in the Central Savannah River Area, South Carolina and Georgia</span></p> <p>SciTech Connect</p> <p>Stephenson, D.; Stieve, A.</p> <p>1992-03-01</p> <p>Interpretation of several generations of seismic reflection data and potential field data suggests the presence of several crustal blocks within the <span class="hlt">basement</span> beneath the Coastal Plain in the Central Savannah River Area (CSRA). The seismic reflection and refraction data include a grid of profiles that capture shallow and deep reflection events and traverse the Savannah River Site and vicinity. Potential field data includes aeromagnetic, ground magnetic surveys, reconnaissance and detailed gravity surveys. Subsurface data from recovered core are used to constrain the model.Interpretation of these data characteristically indicate a southeast dipping <span class="hlt">basement</span> surface with some minor highs and lows suggesting an erosional pre-Cretaceous unconformity. This surface is interrupted by several <span class="hlt">basement</span> faults, most of which offset only early Cretaceous sedimentary horizons overlying the erosional surface. The oldest fault is perhaps late Paleozoic because it is truncated at the <span class="hlt">basement</span>/Coastal Plain interface. This fault is related in timing and mechanism to the underlying Augusta fault. The youngest faults deform Coastal Plain sediments of at least Priabonian age (40-36.6 Ma). One of these young faults is the Pen Branch faults, identified as the southeast dipping master fault for the Triassic Dunbarton <span class="hlt">basin</span>. All the Cenozoic faults are probably related in time and mechanism to the nearby, well studied Belair fault.The study area thus contains a set of <span class="hlt">structures</span> evolved from the Alleghanian orogeny through Mesozoic extension to Cenozoic readjustment of the crust. There is a metamorphosed crystalline terrane with several reflector/fault packages, a reactivated Triassic <span class="hlt">basin</span>, a mafic terrane separating the Dunbarton <span class="hlt">basin</span> from the large South Georgia <span class="hlt">basin</span> to the southeast, and an overprint of reverse faults, some reactivated, and some newly formed.</p> </li> <li> <p><span>Nature of <span class="hlt">basement</span> rocks under the Los Angeles <span class="hlt">Basin</span>, southern California, as inferred from aeromagnetic data</span></p> <p>SciTech Connect</p> <p>Langenheim, V.E.; Jachens, R.C. . Branch of Geophysics)</p> <p>1993-04-01</p> <p>The Los Angeles (L.A.) <span class="hlt">Basin</span>, one of the world's richest oil-producing <span class="hlt">basins</span>, is underlain by at least two <span class="hlt">basement</span> assemblages. Because the thickness of the <span class="hlt">basin</span> sediments reaches up to a minimum of 10 km, magnetic data allow a more regional view of the juxtaposition and nature of <span class="hlt">basement</span> rocks than do available drill-hole data. Aeromagnetic data indicate that a zone of magnetic rocks extends along the coast east of the Newport-Inglewood fault zone from the San Joaquin Hills northwest to the Santa Monica Mountains. The magnetic highs produced by these rocks appear to be a continuation of intense magnetic highs that are present over exposed rocks of the Peninsular Ranges batholith to the southwest. Modeling of a 180 nT magnetic high over the San Joaquin Hills indicates that the tops of two concealed magnetic sources are at about 1.5 km and 4.5 km depth, which places these bodies at or beneath the <span class="hlt">basement</span> surface. Modeling of magnetic highs over the exposed batholithic rocks to the south reveals a source with similar geometry and magnetic properties. The associated gravity highs of the San Joaquin Hills suggest that the probable lithology of these concealed magnetic bodies is a dense crystalline rock such as gabbro.</p> </li> <li> <p><span>Precambrian <span class="hlt">basement</span> geology of the Permian <span class="hlt">basin</span> region of west Texas and Eastern New Mexico: A geophysical perspective</span></p> <p>SciTech Connect</p> <p>Adams, D.C.; Keller, G.R.</p> <p>1996-03-01</p> <p>Because most of the Permian <span class="hlt">basin</span> region of west Texas and southern New Mexico is covered by Phanerozoic rocks, other means must be found to examine the Precambrian upper crustal geology of the region. We have combined geologic information on the Precambrian from outcrops and wells with geophysical information from gravity and magnetic surveys in an integrated analysis of the history and <span class="hlt">structure</span> of <span class="hlt">basement</span> rocks in the region. Geophysical anomalies can be related to six Precambrian events: formation of the Early Proterozoic outer tectonic belt, igneous activity in the southern Granite-Rhyolite province, an episode of pre-Grenville extension, the Grenville orogeny, rifting to form the Delaware aulacogen, and Eocambrian rifting to form the early Paleozoic continental margin. Two geophysical features were studied in detail: the Abilene gravity minimum and the Central <span class="hlt">Basin</span> platform gravity high. The Abilene gravity minimum is shown to extend from the Delaware <span class="hlt">basin</span> across north-central Texas and is interpreted to be caused by a granitic batholith similar in size to the Sierra Nevada batholith in California and Nevada. This batholith appears to be related to formation of the southern Granite- Rhyolite province, possibly as a continental margin arc batholith. Because of this interpretation, we have located the Grenville tectonic front southward from its commonly quoted position, closer to the Llano uplift. Middle Proterozoic mafic intrusions are found to core the Central <span class="hlt">Basin</span> platform and the Roosevelt uplift. These intrusions formed at about 1.1 Ga and are related in time to both the Mid-Continent rift system and the Grenville orogeny in Texas. Precambrian <span class="hlt">basement</span> <span class="hlt">structures</span> and changes in lithology have influenced the <span class="hlt">structure</span> and stratigraphy in the overlying Permian <span class="hlt">basin</span>, and thus have potential exploration significance.</p> </li> <li> <p><span>Venezuela <span class="hlt">Basin</span> crustal <span class="hlt">structure</span></span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Diebold, J. B.; Stoffa, P. L.; Buhl, P.; Truchan, M.</p> <p>1981-09-01</p> <p>Velocity-depth profiles derived from six two-ship expanding spread experiments, in combination with other geophysical data, define the characteristics of two distinct types of Venezuela <span class="hlt">Basin</span> crust and the boundary between them. Each two-ship common midpoint reflection/refraction profile is automatically transformed into the τ-p plane, `picked' and interpreted to provide V(Z) functions with appropriate confidence bounds. The results, together with gravity, magnetic, and near-vertical incidence reflection data, reveal a 50,000 km2 triangle of Venezuela <span class="hlt">Basin</span> crust which resembles normal oceanic crust in a magnetic quiet zone. North and west of this triangle lies the previously defined, thick `Caribbean' crust, having two distinct layers above the M discontinuity. Acoustic <span class="hlt">basement</span> there appears unusually smooth due to extensive basaltic sills and flows which were cored at Deep Sea Drilling Project sites 146/149(sills), and 150 (flows); also, depths to mantle are greater than normal. Interpretations of near-vertical and wide-angle reflection data show that the extra crustal thickness is due not only to the emplacement of the flows but also to the crust below being somewhat thicker than normal. The boundary between the two crustal areas has a NE-SW trend which parallels the dominant <span class="hlt">structural</span> and magnetic lineations.This boundary coincides in position, though not in trend, with the previously defined `central Venezuela <span class="hlt">Basin</span> fault zone'. Further study is required to determine whether this boundary is of tectonic origin or if it represents a change in style of crustal production.</p> </li> <li> <p><span>3D gravity interpretation of the pre-Tertiary <span class="hlt">basement</span> in the intramontane depressions of the Western Carpathians: a case study from the Turiec <span class="hlt">Basin</span></span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Bielik, Miroslav; Krajňák, Martin; Makarenko, Irina; Legostaeva, Olga; Starostenko, Vitaly I.; Bošanský, Marián; Grinč, Michal; Hók, Jozef</p> <p>2013-10-01</p> <p>New results related to the thickness and density of the sedimentary fill of the Turiec <span class="hlt">Basin</span> allowed us to construct the first original stripped gravity map for this typical intramontane Neogene depression of the Western Carpathians. The stripped gravity map of the Turiec <span class="hlt">Basin</span> represents the Bouguer gravity anomalies corrected for the gravity effect of the density contrast of its Quaternary-Tertiary sedimentary <span class="hlt">basin</span> fill. It means that the map reflects the gravity effects of the density inhomogeneities which are located beneath the sedimentary <span class="hlt">basin</span> fill. This map is therefore suitable for the interpretation of the <span class="hlt">structure</span> and composition of the pre-Tertiary <span class="hlt">basement</span>. Based on the new data analysis, two different density models of the sedimentary fill were constructed. The 3D density modelling was used to calculate the gravity effect of the density models. The stripped gravity maps were produced by subtracting the density model gravity effects from Bouguer anomalies. The regional trend was also removed from the stripped gravity maps. The residual stripped gravity maps were consequently used for geological interpretation of the pre-Tertiary <span class="hlt">basement</span> of the Turiec <span class="hlt">Basin</span>. The pre-Tertiary <span class="hlt">basement</span> of the Turiec <span class="hlt">Basin</span> can be divided into northern and southern parts due to its gravity characteristics. Furthermore the northern part can be split into two domains: western and eastern. The crystalline <span class="hlt">basement</span> of the western domain is probably formed by the Hercynian crystalline <span class="hlt">basement</span> of the Tatric Unit. In the eastern domain the <span class="hlt">basement</span> could consist mostly of the Mesozoic complexes of the Fatric Unit. The southern part of the pre-Tertiary <span class="hlt">basement</span> of the Turiec <span class="hlt">Basin</span> is built predominantly by Mesozoic complexes of the Hronic Unit. It is suggested that the Hronic Unit also forms the bedrock of the volcano-sedimentary complex of the Kremnické vrchy Mts. The resultant stripped gravity maps and the map of total horizontal gravity gradients have also proven to be very</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li>«</li> <li>1</li> <li class="active"><span>2</span></li> <li>3</li> <li>4</li> <li>5</li> <li>»</li> </ul> </div> </div> </div> </div> </a> </li> </div> </div> </div> <br><img src="" alt="Canada Goose Amsterdam"><br> <br><a href=""><b>canadá ganso usa</b></a> <br><a href=""><b>canada goose polar bear</b></a> <br><a href=""><b>canada goose citadel</b></a> <br><a href=""><b>canada goose naisten takki</b></a> <br><a href=""><b>canada ganso chicago</b></a> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li>«</li> <li>1</li> <li>2</li> <li class="active"><span>3</span></li> <li>4</li> <li>5</li> <li>»</li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><span>Evaluating the fate of freshwater lenses on atoll islands after <span class="hlt">eustatic</span> <span class="hlt">sea-level</span> rise and cyclone-driven inundation: A modelling approach</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Terry, James P.; Chui, Ting Fong May</p> <p>2012-05-01</p> <p>Dispersed human populations inhabiting remote atolls across the tropical Pacific Ocean are reliant on the viability of thin freshwater lenses (FWLs) contained within the island coralline sediments for their survival. Yet FWLs are uniquely fragile and easily damaged by saline intrusion. <span class="hlt">Eustatic</span> <span class="hlt">sea-level</span> rise (SLR) and sea flooding generated by intense tropical cyclones therefore pose special perils for continued existence on atolls. In this work, mathematical modelling is used to examine the effects on an atoll freshwater lens of various projected long-term SLR scenarios (10, 20, and 40 cm). A cyclone-driven wave washover event is then simulated in order to observe the responses and recovery of the FWL, subsequent to the SLR scenarios imposed. A key attribute of our model design is the inclusion of a topographic depression containing a low-lying fresh swamp in the atoll islet interior (which is often ignored), where seawater accumulates during inundation. Results indicate that a 40 cm SLR produces a major impact: the FWL decreases in thickness by approximately 50%, develops a brackish centre and contracts to a shrunken 'doughnut' morphology. Following cyclone inundation, observed salinity profiles are illuminating. Steep salinity gradients show how a strong saline plume forms at shallow depths, but also reveal the existence of an undisturbed fresh horizon beneath the salt plume under both present conditions and the modest 10 cm SLR scenario. Within the preserved fresh horizon, salt concentrations are maintained below 1.5 g/L (i.e. within usable limits) for at least a year. In contrast, the diminished freshwater lenses that exist after 20 and 40 cm SLR then exhibit far less resilience to saline damage over comparable post-cyclone timeframes. The findings point towards Pacific atolls becoming increasingly uninhabitable long before their complete submergence by <span class="hlt">sea-level</span> rise, owing to irrecoverable groundwater salinisation seriously reducing the availability of</p> </li> <li> <p><span>Generalized Cauchy model of <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> with long-range dependence</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Li, Ming; Li, Jia-Yue</p> <p>2017-10-01</p> <p>This article suggests the contributions with two highlights. One is to propose a novel model of <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> (<span class="hlt">sea</span> <span class="hlt">level</span> for short), which is called the generalized Cauchy (GC) process. It provides a new outlook for the description of local and global behaviors of <span class="hlt">sea</span> <span class="hlt">level</span> from a view of fractal in that the fractal dimension D that measures the local behavior of <span class="hlt">sea</span> <span class="hlt">level</span> and the Hurst parameter H which characterizes the global behavior of <span class="hlt">sea</span> <span class="hlt">level</span> are independent of each other. The other is to show that <span class="hlt">sea</span> <span class="hlt">level</span> appears multi-fractal in both spatial and time. Such a meaning of multi-fractal is new in the sense that a pair of fractal parameters (D, H) of <span class="hlt">sea</span> <span class="hlt">level</span> is varying with measurement sites and time. This research exhibits that the ranges of D and H of <span class="hlt">sea</span> <span class="hlt">level</span>, in general, are 1 ≤ D < 2 and 0 . 5 < H < 1, respectively but D is independent of H. With respect to the global behavior of <span class="hlt">sea</span> <span class="hlt">level</span>, we shall show that H > 0 . 96 for all data records at all measurement sites, implying that strong LRD may be a general phenomenon of <span class="hlt">sea</span> <span class="hlt">level</span>. On the other side, regarding with the local behavior, we will reveal that there appears D = 1 or D ≈ 1 for data records at a few stations and at some time, but D > 0 . 96 at most stations and at most time, meaning that <span class="hlt">sea</span> <span class="hlt">level</span> may appear highly local irregularity more frequently than weak local one.</p> </li> <li> <p><span>The anatomy of recent large <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> in the Mediterranean Sea</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Landerer, Felix W.; Volkov, Denis L.</p> <p>2013-02-01</p> <p><title type="main">Abstract During the boreal winter months of 2009/2010 and 2010/2011, Mediterranean mean <span class="hlt">sea</span> <span class="hlt">level</span> rose 10 cm above the average monthly climatological values. The non-seasonal anomalies were observed in sea surface height (from altimetry), as well as ocean mass (from gravimetry), indicating they were mostly of barotropic nature. These relatively rapid basin-wide <span class="hlt">fluctuations</span> occurred over time scales of 1-5 months. Here we use observations and re-analysis data to attribute the non-seasonal <span class="hlt">sea</span> <span class="hlt">level</span> and ocean mass <span class="hlt">fluctuations</span> in the Mediterranean Sea to concurrent wind stress anomalies over the adjacent subtropical Northeast Atlantic Ocean, just west of the Strait of Gibraltar, and extending into the strait itself. The observed Mediterranean <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> are strongly anti-correlated with the monthly North-Atlantic-Oscillation (NAO) index.</p> </li> <li> <p><span>Reconstruction of Caspian <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span>: Radiocarbon dating coastal and bottom deposits</span></p> <p>SciTech Connect</p> <p>Karpytchev, Yu.A. )</p> <p>1993-01-01</p> <p>Owing to the large basin area of the Caspian Sea, <span class="hlt">fluctuations</span> in its level reflect climatic changes in the northern hemisphere. To reconstruct these <span class="hlt">fluctuations</span>, they collected mollusk shells, plant debris, carbonates and organic matter samples for [sup 14]C dating from deposits of ancient salt marshes, depressions and bars formed during significant <span class="hlt">sea-level</span> decline they studied the impact of eolian sedimentation via parallel dating of carbonates and other materials. The data demonstrate that <span class="hlt">sea</span> <span class="hlt">level</span> rises during periods of cooling and falls during warming periods; this is true for both long-term (2--2.5 ka) and short-term climatic changes.</p> </li> <li> <p><span>A "chaos" of Phanerozoic <span class="hlt">eustatic</span> curves</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Ruban, Dmitry A.</p> <p>2016-04-01</p> <p>The knowledge of eustasy has changed during the past two decades. Although there is not any single global <span class="hlt">sea-level</span> curve for the entire Phanerozoic, new curves have been proposed for all periods. For some geological time intervals, there are two and more alternative reconstructions, from which it is difficult to choose. A significant problem is the available <span class="hlt">eustatic</span> curves are justified along different geological time scales (sometimes without proper explanations), which permits to correlate <span class="hlt">eustatic</span> events with the possible error of 1-3 Ma. This degree of error permits to judge about only substage- or stage-order global <span class="hlt">sea-level</span> changes. Close attention to two geological time slices, namely the late Cambrian (Epoch 3‒Furongian) and the Late Cretaceous, implies that only a few <span class="hlt">eustatic</span> events (6 events in the case of the late Cambrian and 9 events in the case of the Late Cretaceous) appear on all available alternative curves for these periods, and different (even opposite) trends of <span class="hlt">eustatic</span> <span class="hlt">fluctuations</span> are shown on these curves. This reveals significant uncertainty in our knowledge of eustasy that restricts our ability to decipher factors responsible for regional transgressions and regressions and relative <span class="hlt">sea-level</span> changes. A big problem is also inadequate awareness of the geological research community of the new <span class="hlt">eustatic</span> developments. Generally, the situation with the development and the use of the Phanerozoic <span class="hlt">eustatic</span> reconstructions seems to be ;chaotic;. The example of the shoreline shifts in Northern Africa during the Late Cretaceous demonstrates the far-going consequences of this situation. The practical recommendations to avoid this ;chaos; are proposed. Particularly, these claim for good awareness of all <span class="hlt">eustatic</span> developments, their critical discussion, and clear explanation of the employed geological time scale.</p> </li> <li> <p><span>Pleistocene <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> and human evolution on the southern coastal plain of South Africa</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Compton, John S.</p> <p>2011-03-01</p> <p>Humans evolved in Africa, but where and how remain unclear. Here it is proposed that the southern coastal plain (SCP) of South Africa may have served as a geographical point of origin through periodic expansion and contraction (isolation) in response to glacial/interglacial changes in <span class="hlt">sea</span> <span class="hlt">level</span> and climate. During Pleistocene interglacial highstands when <span class="hlt">sea</span> <span class="hlt">level</span> was above -75 m human populations were isolated for periods of 360-3400 25-yr generations on the SCP by the rugged mountains of the Cape Fold Belt, climate and vegetation barriers. The SCP expands five-fold as <span class="hlt">sea</span> <span class="hlt">level</span> falls from -75 to -120 m during glacial maxima to form a continuous, unobstructed coastal plain accessible to the interior. An expanded and wet glacial SCP may have served as a refuge to humans and large migratory herds and resulted in the mixing of previously isolated groups. The expansive glacial SCP habitat abruptly contracts, by as much as one-third in 300 yr, during the rapid rise in <span class="hlt">sea</span> <span class="hlt">level</span> associated with glacial terminations. Rapid flooding may have increased population density and competition on the SCP to select for humans who expanded their diet to include marine resources or hunted large animals. Successful adaptations developed on an isolated SCP are predicted to widely disperse during glacial terminations when the SCP rapidly contracts or during the initial opening of the SCP in the transition to glacial maxima. The hypothesis that periodic expansion and contraction of the SCP, as well as the coastal plain of North Africa, contributed to the stepwise origin of our species over the last 800 thousand years (kyr) is evaluated by comparing the archeological, DNA and <span class="hlt">sea-level</span> records. These records generally support the hypothesis, but more complete and well dated records are required to resolve the extent to which <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> influenced the complex history of human evolution.</p> </li> <li> <p><span>Global <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> and uncertainties through a Wilson cycle based on ocean basin volume reconstructions</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Wright, Nicky; Seton, Maria; Williams, Simon E.; Dietmar Müller, R.</p> <p>2017-04-01</p> <p>Variations in the volume of ocean basins is the main driving force for (long-wavelength) changes in <span class="hlt">eustatic</span> <span class="hlt">sea</span> <span class="hlt">level</span> in an ice-free world, i.e. most of the Mesozoic and Cenozoic. The volume of ocean basins is largely dependent on changes in the seafloor spreading history, which can be reconstructed based on an age-depth relationship for oceanic crust and an underlying global plate kinematic model. Ocean basin volume reconstructions need to include: (1) a predicted history of back-arc basin formation, including where geological evidence exists for the opening and closing of back-arc basins within a single Wilson cycle, (2) the emplacement and subsidence of oceanic plateaus (LIPs), (3) variations in sediment thickness through time, and (4) a reconstruction of the depth of continental margins and fragments. Unfortunately, due to subduction of oceanic crust, we must rely on synthetically modelled ocean crust for much of Earth's history, for which it is impossible to ground truth the history of LIPs and sediment thickness. In order to improve reconstructions of <span class="hlt">sea</span> <span class="hlt">level</span> on geologic time scales and assess the uncertainty in deriving the volume of ocean basins based on a global plate kinematic model, we investigate the influence of these poorly constrained features (e.g. LIPs, back-arc basins, sediment thickness, passive margins) on ocean basin volume since 230 Ma (i.e. throughout an entire Wilson cycle). We assess the characteristics for each feature at present-day and during well-constrained times during the Cenozoic, and create suites of alternative paleobathymetry grids which incorporate varying degrees of each feature's influence. Further, we derive a global <span class="hlt">sea</span> <span class="hlt">level</span> curve based only on the reconstruction of ocean basin volume (i.e. excluding effects such as dynamic topography and glaciation), and present the influence of each component and their uncertainties through time. We find that by incorporating reasonable predictions for these components during times</p> </li> <li> <p><span>Relative <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> since deglaciation in western North America</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Shugar, D. H.; Walker, I. J.; Lian, O. B.; Eamer, J.; Neudorf, C. M.</p> <p>2013-12-01</p> <p>We synthesize the state of knowledge regarding post-glacial <span class="hlt">sea-level</span> changes on the Pacific coast of North America based on more than 2,000 radiocarbon dates from Oregon to Alaska. Relative <span class="hlt">sea-level</span> (RSL) history over the late Quaternary is complex owing to regional differences in crustal deformation (neotectonics), changes in global ocean volumes (eustasy) and the depression and rebound of the Earth's crust in response to ice sheets on land (isostasy). The RSL history is further complicated by the diachronous timing of the Last Glacial Maximum (LGM) and subsequent ice retreat across the region. For instance, the LGM ranged in timing from as early as 25 ka (14C years) BP in south-central Alaska, to between 15-14 ka BP at its southernmost extent in southwest BC and northern Washington. During this time, the Cordilleran Ice Sheet depressed the crust over which it formed and, as the ice thinned and retreated, the sea rapidly transgressed isostatically depressed lowland areas. Early-postglacial RSL highstands within the region range from ~25 masl in Cook Inlet, Alaska, to approximately 200 masl at fjord head locations such as Kitimat and in the Lower Mainland of southern BC. As the crust rebounded, RSL dropped. In contrast to the BC mainland, <span class="hlt">sea</span> <span class="hlt">levels</span> at the LGM were 150 m lower than present in Haida Gwaii on BC's north coast, due to an isostatic forebulge raising the land. Forebulge collapse led to a rise in relative <span class="hlt">sea</span> <span class="hlt">level</span>, up to about 15-18 masl by 9.5 ka BP. Spatial and temporal gaps exist in our understanding of post-glacial <span class="hlt">sea-level</span> change and landscape evolution along the Pacific coast as data constraining RSL <span class="hlt">fluctuations</span> around the LGM are limited (e.g. south-central Alaska). Similarly, we lack understanding of post-glacial <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> on BC's central coast. We present an overview of the differences in RSL patterns from Oregon to south-central Alaska and discuss the geophysical foundations for them, as well as present new data filling data</p> </li> <li> <p><span>Early Pleistocene <span class="hlt">sea</span> <span class="hlt">level</span> and millennial-scale climate <span class="hlt">fluctuations</span>: a view from the tropical Pacific</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Alix Jakob, Kim; Friedrich, Oliver; Pross, Jörg</p> <p>2015-04-01</p> <p>This project aims at deciphering the rate of <span class="hlt">sea</span> <span class="hlt">level</span> variability and its effect on millennial-scale climate <span class="hlt">fluctuations</span> during the final phase of the intensification of northern hemisphere glaciation (NHG). Millennial-scale climate <span class="hlt">fluctuations</span> appear to have changed significantly at glacial-interglacial time scales during the late Pliocene and Pleistocene. Thereby, millennial-scale climate <span class="hlt">fluctuations</span> under a warmer climate during late Pliocene and early Pleistocene show markedly lower ampitudes compared to the <span class="hlt">fluctuations</span> of the late Pleistocene. Numerous Pleistocene proxy records (e.g. McManus et al., 1999) suggest that this difference can be explained by an ice-volume/<span class="hlt">sea-level</span> threshold that amplifies millennial-scale climate <span class="hlt">fluctuations</span> and was not reached prior to the Mid-Pleistocene Transition (MPT). However, new records question the existence of this threshold (Bolton et al., 2010) and indicate that either the amplification of millennial-scale climate <span class="hlt">fluctuations</span> before the MPT required a higher ice-volume threshold than in the late Pleistocene, that ice-volume had no significant effect on the amplitude of climate <span class="hlt">fluctuations</span>, and/or the available <span class="hlt">sea</span> <span class="hlt">level</span> estimates for the early Pleistocene are inaccurate. For identifying the mechanisms underlying the dynamics of early Pleistocene ice sheets, material from the tropical Pacific Ocean (ODP Site 849) is studied over a time interval from 2.6 to 2.4 Ma (marine isotope stages 104 to 96). In summary, the main deliverables are (1) the establishment of a precise δ18O chemostratigraphy using the benthic foraminifera Cibicidoides wuellerstorfi by tuning the δ18O dataset to the LR04 benthic isotope stack (Lisiecki & Raymo, 2005), and (2) providing high-resolution (˜700 years) Mg/Ca and δ18O datasets using the benthic foraminifera Oridorsalis umbonatus and the planktonic foraminifera Globigerinoides ruber. This combined geochemical approach will be used to address the following research questions: (1</p> </li> <li> <p><span>Interannual <span class="hlt">fluctuations</span> of the global mean <span class="hlt">sea</span> <span class="hlt">level</span> during the altimetry era</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Dieng, H.; Munier, S.; Henry, O.; Palanisamy, H.; Meyssignac, B.; Cazenave, A. A.</p> <p>2012-12-01</p> <p>The detrended global mean <span class="hlt">sea</span> <span class="hlt">level</span> (GMSL) displays significant year-to-year <span class="hlt">fluctuations</span> of 2-3 mm amplitude, as revealed by satellite altimetry over the past 2 decades. In particular, the detrended GMSL shows positive anomalies during El Nino and negative anomalies during La Nina. Previous studies (Llovel et al, 2011, Boening et al., 2012, Cazenave et al., 2012) have shown that these ENSO-related anomalies are mostly caused by ocean mass variations linked to changes of the global water cycle, with precipitation excess (deficit ) over the oceans (land) during El Nino, and inversely during La Nina. Here, we study the respective contributions of the mass and steric contributions to the interannual GMSL <span class="hlt">fluctuations</span> over the whole altimetry period (since 1993); We find that over this time span, interannual GMSL <span class="hlt">fluctuations</span> are in general poorly correlated to the steric component while ocean mass variations explain most of the observed year to year oscillations, even apart from ENSO events . These ocean mass oscillations appear inversely correlated to the total land water storage oscillation. However over the oceanic domain, interannual mass changes are not uniformly distributed but mostly confined in the tropical Pacific and Indian oceans. We also find that at some periods (in particular during the 2010/2011 La Nina event), the steric <span class="hlt">sea</span> <span class="hlt">level</span> contribution has to be accounted for, in addition to the mass term, to fully explain the observed GMSL anomaly.</p> </li> <li> <p><span><span class="hlt">Sea-level</span> <span class="hlt">fluctuations</span> show Ocean Circulation controls Atlantic Multidecadal Variability</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>McCarthy, Gerard; Haigh, Ivan; Hirschi, Joel; Grist, Jeremy; Smeed, David</p> <p>2015-04-01</p> <p>We present observational evidence that ocean circulation controls the decadal evolution of heat content and consequently sea-surface temperatures (SST) in the North Atlantic. One of the most prominent modes of Atlantic variability is the Atlantic multidecadal oscillation (AMO) observed in SSTs. Positive (negative) phases of the AMO are associated with warmer (cooler) SSTs. Positive phases of the AMO have been linked with decadal climate <span class="hlt">fluctuations</span> including increased summer precipitation in Europe; increased northern hemisphere land temperatures, fewer droughts in the Sahel region of Africa and increased Atlantic hurricane activity. It is widely believed that the Atlantic circulation controls the phases of the AMO by controlling the decadal changes in heat content in the North Atlantic. However, due to the lack of ocean circulation observations, this link has not been previously proven. We present a new interpretation of the <span class="hlt">sea-level</span> gradient along to the east coast of the United States to derive a measure of ocean circulation spanning decadal timescales. We use this to estimate heat content changes that we validate against direct estimates of heat content. We use the longevity of the tide gauge record to show that circulation, as interpreted in <span class="hlt">sea-level</span> gradient changes, drives the major transitions in the AMO since the 1920's. We show that the North Atlantic Oscillation is highly correlated with this <span class="hlt">sea-level</span> gradient, indicating that the atmosphere drives the circulation changes. The circulation changes are essentially integrated by the ocean in the form of ocean heat content and returned to the atmosphere as the AMO. An additional consequence of our interpretation is that recently reported accelerations in <span class="hlt">sea-level</span> rise along the US east coast are consistent with a declining AMO that has been predicted by a number of authors.</p> </li> <li> <p><span>Orbital forced <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> during the Middle Eocene (ODP site 1172, East Tasman Plateau)</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Warnaar, J.; Stickley, C.; Jovane, L.; Roehl, U.; Brinkhuis, H.; Visscher, H.</p> <p>2004-12-01</p> <p>Ocean Drilling Program leg 189 was undertaken to test and refine the hypothesis (by Kennett et al., 1975), that the reconfiguration of continents around Antarctica (e.g.: the opening of the Tasmanian Gateway and Drake passage) led to the onset of the Antarctic Circumpolar Current that, in turn, would cause thermal isolation and hence cooling of Antarctica. This would possibly even cause global cooling, as suggested by the 33.3 Ma Oi1 event. The cores of leg 189, site 1172 on the eastern side of the Tasmanian Gateway provided a nearly complete succession of Eocene and Oligocene sediments. Cyclostratigraphic analysis based on XRF derived Ca and Fe records indicates distinct Milankovitch cyclicity between 40 and 36 Ma. (Röhl et al, in press). In the core-section representing magnetochron 18n-1n, the Ca record shows precession cycles in combination with obliquity, suggested to reflect <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">fluctuations</span> (Röhl et al, in press). New datasets include microfossil data (organic-walled dinoflagellate cysts, pollen/spores and diatoms), loss-on-ignition measurements, magnetic data (environmental magnetics - ARM). Here, we aim to further investigate the proposed relationship between astronomical forcing and <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span>. Additionally, we aim to obtain insight in the palaeoecology of the distinct endemic circum-Antarctic late Middle to Late Eocene dinoflagellate cyst assemblages. Results corroborate the concept that the cyclicity recorded by Ca and Fe measurements is the result of <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span>. This implies that during late Middle Eocene times, astronomical forcing has modulated <span class="hlt">sea</span> <span class="hlt">level</span> - most likely through Antarctic ice buildup and meltdown. In turn, this would indicate the presence of significant, though probably modest, ice masses already ~40 Ma ago, well before the onset of the Antarctic Circumpolar Current. Kennett, J. P., R. E. Houtz, et al. (1975). Development of the circum-Antarctic current. Science 186: 144-147. Röhl, U.; H. Brinkhuis, C</p> </li> <li> <p><span>Global <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> during the Last Interglaciation (MIS 5e)</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Hearty, Paul J.; Hollin, John T.; Neumann, A. Conrad; O'Leary, Michael J.; McCulloch, Malcolm</p> <p>2007-09-01</p> <p>The geomorphology and morphostratigraphy of numerous worldwide sites reveal the relative movements of <span class="hlt">sea</span> <span class="hlt">level</span> during the peak of the Last Interglaciation (Marine Isotope Stage (MIS) 5e, assumed average duration between 130±2 and 119±2 ka). Because <span class="hlt">sea</span> <span class="hlt">level</span> was higher than present, deposits are emergent, exposed, and widespread on many stable coastlines. Correlation with MIS 5e is facilitated by similar morphostratigraphic relationships, a low degree of diagenesis, uranium-thorium (U/Th) ages, and a global set of amino-acid racemization (AAR) data. This study integrates information from a large number of sites from tectonically stable areas including Bermuda, Bahamas, and Western Australia, and some that have experienced minor uplift (˜2.5 m/100 ka), including selected sites from the Mediterranean and Hawaii. Significant <span class="hlt">fluctuations</span> during the highstand are evident at many MIS 5e sites, revealed from morphological, stratigraphic, and sedimentological evidence. Rounded and flat-topped curves derived only from reef tracts are incomplete and not representative of the entire interglacial story. Despite predictions of much different <span class="hlt">sea-level</span> histories in Bermuda, the Bahamas, and Western Australia due to glacio- and hydro-isostatic effects, the rocks from these sites reveal a nearly identical record during the Last Interglaciation. The Last Interglacial highstand is characterized by several defined <span class="hlt">sea-level</span> intervals (SLIs) that include: (SLI#1) post-glacial (MIS 6/5e Termination II) rise to above present before 130 ka; (SLI#2) stability at +2 to +3 m for the initial several thousand years (˜130 to ˜125 ka) during which fringing reefs were established and terrace morphology was imprinted along the coastlines; (SLI#3) a brief fall to near or below present around 125 ka; (SLI#4) a secondary rise to and through ˜+3-4 m (˜124 to ˜122 ka); followed by (SLI#5) a brief period of instability (˜120 ka) characterized by a rapid rise to between +6 to +9 m during</p> </li> <li> <p><span>Humboldt Bay Vertical Reference System Working Group: unraveling tectonic and <span class="hlt">eustatic</span> factors of <span class="hlt">sea</span> <span class="hlt">level</span> rise in northern California, Humboldt Bay</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Williams, T. B.; Anderson, J. K.; Burgette, R. J.; Gilkerson, W.; Hemphill-Haley, M.; Leroy, T. H.; Patton, J. R.; Southwick, E.; Stallman, J.; Weldon, R. J.</p> <p>2012-12-01</p> <p><span class="hlt">Sea-level</span> rise is a critical factor in managing estuarine ecosystems, maintaining public infrastructure, and mitigating geologic hazards along north coastal California. The coastal region between Fort Bragg, California and Vancouver Island experiences ongoing land-level changes due to Cascadia subduction zone tectonics. These tectonic land-level changes sufficiently modify relative <span class="hlt">sea</span> <span class="hlt">level</span> such that <span class="hlt">sea-level</span> rise cannot be accurately estimated without determining the tectonic contribution. We use tide gages and precise level-loop surveys to observe modern land and water surface elevations around Humboldt Bay. These modern data, combined with historic survey data, will be used to deconfound the various factors contributing to relative <span class="hlt">sea</span> <span class="hlt">level</span> change. Independent analysis of existing NOAA tide gages and EarthScope CGPS stations indicate 2.5 mm/yr of land subsidence near Humboldt Bay and 2 mm/yr of land uplift in Crescent City. Presuming the bulk of the strain accumulation is due to the southern portion of the Cascadia subduction zone, these data suggest Humboldt Bay is west of the locked zone, not to the east as previously reported by several researchers.</p> </li> <li> <p><span>Effects of Pleistocene <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> on mangrove population dynamics: a lesson from Sonneratia alba.</span></p> <p>PubMed</p> <p>Yang, Yuchen; Li, Jianfang; Yang, Shuhuan; Li, Xinnian; Fang, Lu; Zhong, Cairong; Duke, Norman C; Zhou, Renchao; Shi, Suhua</p> <p>2017-01-18</p> <p>A large-scale systematical investigation of the influence of Pleistocene climate oscillation on mangrove population dynamics could enrich our knowledge about the evolutionary history during times of historical climate change, which in turn may provide important information for their conservation. In this study, phylogeography of a mangrove tree Sonneratia alba was studied by sequencing three chloroplast fragments and seven nuclear genes. A low level of genetic diversity at the population level was detected across its range, especially at the range margins, which was mainly attributed to the steep <span class="hlt">sea-level</span> drop and associated climate <span class="hlt">fluctuations</span> during the Pleistocene glacial periods. Extremely small effective population size (Ne) was inferred in populations from both eastern and western Malay Peninsula (44 and 396, respectively), mirroring the fragility of mangrove plants and their paucity of robustness against future climate perturbations and human activity. Two major genetic lineages of high divergence were identified in the two mangrove biodiversity centres: the Indo-Malesia and Australasia regions. The estimated splitting time between these two lineages was 3.153 million year ago (MYA), suggesting a role for pre-Pleistocene events in shaping the major diversity patterns of mangrove species. Within the Indo-Malesia region, a subdivision was implicated between the South China Sea (SCS) and the remaining area with a divergence time of 1.874 MYA, corresponding to glacial vicariance when the emerged Sunda Shelf halted genetic exchange between the western and eastern coasts of the Malay Peninsula during Pleistocene <span class="hlt">sea-level</span> drops. Notably, genetic admixture was observed in populations at the boundary regions, especially in the two populations near the Malacca Strait, indicating secondary contact between divergent lineages during interglacial periods. These interregional genetic exchanges provided ample opportunity for the re-use of standing genetic variation</p> </li> <li> <p><span>Millennial/submillennial-scale <span class="hlt">sea-level</span> <span class="hlt">fluctuations</span> in western Mediterranean during the second highstand of MIS 5e</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Dabrio, C. J.; Zazo, C.; Cabero, A.; Goy, J. L.; Bardají, T.; Hillaire-Marcel, C.; González-Delgado, J. A.; Lario, J.; Silva, P. G.; Borja, F.; García-Blázquez, A. M.</p> <p>2011-02-01</p> <p>This paper investigates a series of small-scale, short-lived <span class="hlt">fluctuations</span> of <span class="hlt">sea</span> <span class="hlt">level</span> registered in a prograding barrier spit that grew during the MIS 5e. This interglacial includes three highstands ( Zazo et al., 2003) and we focus on the second highstand, of assumed duration ˜10 ± 2 ka, given that U-Th ages do not provide more accurate data. Geometry and 3D architecture of beach facies, and thin-section petrography were used to investigate eight exposed offlapping subunits separated by seven conspicuous erosion surfaces, all interpreted as the result of repeated small-scale <span class="hlt">fluctuations</span> of <span class="hlt">sea</span> <span class="hlt">level</span>. Each subunit records a relatively rapid rise of <span class="hlt">sea</span> <span class="hlt">level</span> that generated a gravelly shoreface with algal bioherms and a sandy uppermost shoreface and foreshore where most sand accumulated. A second range of still smaller-scaled oscillations of <span class="hlt">sea</span> <span class="hlt">level</span> has been deduced in this phase of <span class="hlt">sea-level</span> <span class="hlt">fluctuation</span> from lateral and vertical shifts of the foreshore-plunge-step-uppermost shoreface facies. Eventually, progradation with gently falling <span class="hlt">sea</span> <span class="hlt">level</span> took place and foreshore deposits underwent successive vadose cementation and subaerial dissolution, owing to relatively prolonged exposure. Later recovery of <span class="hlt">sea</span> <span class="hlt">level</span> re-established the highstand with <span class="hlt">sea</span> <span class="hlt">level</span> at approximately the same elevation, and there began deposition of a new subunit. The minimum <span class="hlt">sea-level</span> variation (fall and subsequent rise) required to generate the observed features is 4 m. The time span available for the whole succession of events, and comparison with the Holocene prograding beach ridge complex in the nearby Roquetas (Almería) were used to calculate the periodicity of events. A millennial-suborbital time scale is suggested for <span class="hlt">fluctuations</span> separating subunits and a decadal scale for the minor oscillations inside each subunit.</p> </li> <li> <p><span>Paleo-surfaces of glacio-<span class="hlt">eustatically</span> forced aggradational successions in the coastal area of Rome: Assessing interplay between tectonics and <span class="hlt">sea-level</span> during the last ten interglacials</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Marra, Fabrizio; Florindo, Fabio; Anzidei, Marco; Sepe, Vincenzo</p> <p>2016-09-01</p> <p>Recently acquired geochronological and stratigraphic data provide new information on the sedimentary successions deposited by the Paleo-Tiber River in the coastal and near-coastal area of Rome in consequence of the glacio-<span class="hlt">eustatic</span> changes, allowing to better define their inner geometry and palaeogeographic spatial distribution. In the present work we use this revised sedimentary dataset to provide a geochronologically constrained and tectonically adjusted record of paleo <span class="hlt">sea-level</span> indicators. Aimed at this scope, we review literature data acquired in the last 35 years and using the new geochronological constraints we pinpoint the coastal-to-fluvial terraces of MIS 5 and MIS 7, mapping their relic surfaces in an area of 30 km along the coast north and south of the Tiber River mouth, and 20 km inland of the fluvial valleys of Tiber and Aniene rivers. The geometry of these paleo-surfaces provides constraints on the relative elevation of the <span class="hlt">sea-level</span> during the last interglacials and on the uplift rates in this region during the last 200 ka. In particular, we recognize the previously undetected terraces of MIS 5.3 and MIS 5.1 interstadials, and we assess their spatial relationship with respect to MIS 5.5, providing important information on <span class="hlt">sea-level</span> oscillations during this time span. Comparison with <span class="hlt">sea-level</span> indicators provided by previous aggradational successions deposited during past interglacials spanning MIS 9 through MIS 21 in the coastal area of Rome, also allows us to reconstruct the tectonic history and investigate its relationships with the Middle-Pleistocene volcanic activity of the Roman Comagmatic Region along the Tyrrhenian Sea margin of Italy in the last 900 ka.</p> </li> <li> <p><span>An algorithm based on <span class="hlt">sea</span> <span class="hlt">level</span> pressure <span class="hlt">fluctuations</span> to identify major Baltic inflow events</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Schimanke, Semjon; Dieterich, Christian; Markus Meier, H. E.</p> <p>2014-05-01</p> <p>The Baltic Sea is one of world largest brackish water areas with an estuarine like circulation. It is connected to the world ocean through the narrow Danish straits limiting the exchange of water masses. The deep water of the Baltic Sea is mainly renewed by so called major Baltic inflows which are an important feature to sustain the sensitive steady state of the Baltic Sea. We introduce an algorithm to identify atmospheric variability favourable for major Baltic inflows. The algorithm is based on <span class="hlt">sea</span> <span class="hlt">level</span> pressure fields as the only parameter. Characteristic <span class="hlt">sea</span> <span class="hlt">level</span> pressure pattern <span class="hlt">fluctuations</span> include a precursory phase of 30 days and 10 days of inflow period. The algorithm identifies successfully the majority of observed major Baltic inflows between 1961--2010. In addition, the algorithm finds some occurrences which cannot be related to observed inflows. In these cases with favourable atmospheric conditions inflows were precluded by contemporaneously existing saline water masses or strong freshwater supply. No event is registered during the stagnation period 1983-1993 indicating that the lack of inflows is a consequence of missing favourable atmospheric variability. The only striking inflow which is not identified by the algorithm is the event in January 2003. We demonstrate that this is due to the special evolution of <span class="hlt">sea</span> <span class="hlt">level</span> pressure fields which are not comparable with any other event. Finally, the algorithm is applied to an ensemble of scenario simulations. The result indicates that the number of atmospheric events favourable for major Baltic inflows increases slightly in all scenarios. Possible explanations as for instance more frequent atmospheric blockings or changes in the NAO will be discussed.</p> </li> <li> <p><span>Temporal scaling behavior of <span class="hlt">sea-level</span> change in Hong Kong - Multifractal temporally weighted detrended <span class="hlt">fluctuation</span> analysis</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Zhang, Yuanzhi; Ge, Erjia</p> <p>2013-01-01</p> <p>The rise in global <span class="hlt">sea</span> <span class="hlt">levels</span> has been recognized by many scientists as an important global research issue. The process of <span class="hlt">sea-level</span> change has demonstrated a complex scaling behavior in space and time. Large numbers of tide gauge stations have been built to measure <span class="hlt">sea-level</span> change in the North Pacific Ocean, Indian Ocean, North Atlantic Ocean, and Antarctic Ocean. Extensive studies have been devoted to exploring <span class="hlt">sea-level</span> variation in Asia concerning the Bohai Gulf (China), the Yellow Sea (China), the Mekong Delta (Thailand), and Singapore. Hong Kong, however, a mega city with a population of over 7 million situated in the mouth of the Pear River Estuary in the west and the South China Sea in the east, has yet to be studied, particularly in terms of the temporal scaling behavior of <span class="hlt">sea-level</span> change. This article presents an approach to studying the temporal scaling behavior of <span class="hlt">sea-level</span> change over multiple time scales by analyzing the time series of <span class="hlt">sea-level</span> change in Tai Po Kou, Tsim Bei Tsui, and Quarry Bay from the periods of 1964-2010, 1974-2010, and 1986-2010, respectively. The detection of long-range correlation and multi-fractality of <span class="hlt">sea-level</span> change seeks answers to the following questions: (1) Is the current <span class="hlt">sea-level</span> rise associated with and responsible for the next rise over time? (2) Does the <span class="hlt">sea-level</span> rise have specific temporal patterns manifested by multi-scaling behaviors? and (3) Is the <span class="hlt">sea-level</span> rise is temporally heterogeneous in the different parts of Hong Kong? Multi-fractal temporally weighted de-trended <span class="hlt">fluctuation</span> analysis (MF-TWDFA), an extension of multi-fractal de-trended <span class="hlt">fluctuation</span> analysis (MF-DFA), has been applied in this study to identify long-range correlation and multi-scaling behavior of the <span class="hlt">sea-level</span> rise in Hong Kong. The experimental results show that the <span class="hlt">sea-level</span> rise is long-range correlated and multi-fractal. The temporal patterns are heterogeneous over space. This finding implies that mechanisms associated with the</p> </li> <li> <p><span>Bay sedimentation as controlled by regional crustal behaviour, local tectonics and <span class="hlt">eustatic</span> <span class="hlt">sea-level</span> changes: Coquimbo Formation (Miocene Pliocene), Bay of Tongoy, central Chile</span></p> <p>NASA Astrophysics Data System (ADS)</p> <p>Le Roux, J. P.; Olivares, Danisa M.; Nielsen, Sven N.; Smith, Norman D.; Middleton, Heather; Fenner, Juliane; Ishman, Scott E.</p> <p>2006-02-01</p> <p>The north-facing Bay of Tongoy in central Chile is flanked by topographic highs in the west and east. During the Miocene and Pliocene, the bay extended inland at least 30 km farther south than a present. It was filled with muds, sands, coquinas and gravel during a series of transgressions and regressions related to regional and local tectonic movements combined with global <span class="hlt">sea-level</span> variations. 87Sr/ 86Sr and microfossil dating indicates transgressions between 11.9-11.2 Ma, 10.1-9.5 Ma, 9.0-7.3 Ma, 6.3-5.3 Ma, 4.3-2.2 Ma and 1.7-1.4 Ma. The regional tectonic behaviour of the crust shows general uplifting from 10.5 Ma to 6.9 Ma, associated with subduction of the Juan Fernández Ridge (JFR) beneath this part of the continent. Subsidence followed between 6.9 and 2.1 Ma, in the wake of the southeastward-migrating JFR. The subsequent subduction of an oceanic plateau similar to the JFR caused rapid uplift that led to the final emergence of the bay above <span class="hlt">sea</span> <span class="hlt">level</span>. The Puerto Aldea normal fault along the western limit of the study area was reactivated during the regional uplift and subsidence events, with reverse faulting occurring during the latter phase. Sporadic fault reactivation probably triggered the rapid changes in water depth reflected in the recorded vertical succession of facies.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li>«</li> <li>1</li> <li>2</li> <li class="active"><span>3</span></li> <li>4</li> <li>5</li> <li>»</li> </ul> </div> </div> </div> </div> <br><img src=""><br> <header><h1 class="entry-title" itemprop="headline">Week in Review: Travis Fimmel for Canada Goose, J.Crew Heads to Amsterdam + More</h1> <div class="collection-pub">Published on <time class="entry-time" itemprop="datePublished" datetime="2016-09-18T17:38:29+00:00">September 18, 2016</time> </div> </header><div class="entry-content" itemprop="text"><figure id="attachment_496776" style="max-width: 800px" class="wp-caption aligncenter"><img data-attachment-id="496776" data-permalink="" data-orig-file="" data-orig-size="800,1028" data-comments-opened="1" data-image-meta='{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"1"}' data-image-title="travis-fimmel-2016-canada-goose-fall-winter-campaign-002" data-image-description="" data-medium-file="" data-large-file="" src="" alt="Travis Fimmel sports a camouflage jacket for Canada Goose's fall-winter 2016 campaign." width="800" height="1028" class="size-full wp-image-496776" srcset=" 800w, 450w" sizes="(max-width: 800px) 100vw, 800px"><figcaption class="wp-caption-text">Travis Fimmel sports a camouflage jacket for Canada Goose’s fall-winter 2016 campaign.</figcaption></figure><div id="advads-c4940db86b3dd132560cc1176313646a"></div><p><em>Review the most popular updates from the prior week.</em></p> <p>Travis Fimmel Heads to Newfoundland for Canada Goose’s Fall Campaign<br>7 Must-Haves from H&M’s Fall Studio Collection<br>Mountain Time: Bergdorf Goodman Spotlights Fashions for the Outdoors<br>David Beckham & Kevin Hart Reunite for H&M Road Trip<br>New Fall Arrivals: Gap + Pendleton Collaboration</p> <p><span id="more-496946"></span><figure id="attachment_496491" style="max-width: 800px" class="wp-caption aligncenter"><img data-attachment-id="496491" data-permalink="" data-orig-file="" data-orig-size="600,750" data-comments-opened="1" data-image-meta='{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"1"}' data-image-title="jcrew-2016-october-mens-style-guide-ludlow-glen-plaid-suit" data-image-description="" data-medium-file="" data-large-file="" src="" alt="Clément Chabernaud dons a Glen plaid Ludlow suit with a topcoat from J.Crew." width="800" class="size-full wp-image-496491" srcset=" 600w, 450w" sizes="(max-width: 600px) 100vw, 600px"><figcaption class="wp-caption-text">Clément Chabernaud dons a Glen plaid Ludlow suit with a topcoat for J.Crew’s October 2016 style guide.</figcaption></figure></p> <p>J.Crew Heads to Amsterdam for October’s Style Guide<br>David Gandy Covers Special Edition of <em>GQ Turkey</em><br>Original Penguin Takes to Diner for Fall Campaign<br>Eric Decker Embraces Rugged Style for Superdry’s Fall Campaign<br>Robert Reider Goes Sartorial for Stephen Williams London</p> <figure id="attachment_496303" style="max-width: 800px" class="wp-caption aligncenter"><img data-attachment-id="496303" data-permalink="" data-orig-file="" data-orig-size="800,1047" data-comments-opened="1" data-image-meta='{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"1"}' data-image-title="ansel-elgort-2016-prada-lexpress-styles" data-image-description="" data-medium-file="" data-large-file="" src="" alt="Ansel Elgort pictured in Prada for L'Express Styles." width="800" height="1047" class="size-full wp-image-496303" srcset=" 800w, 450w" sizes="(max-width: 800px) 100vw, 800px"><figcaption class="wp-caption-text">Ansel Elgort pictured in Prada for <em>L’Express Styles</em>.</figcaption></figure><div id="advads-ddbf41495b768e2292d1ba32c54cd374"></div><p>Generation Prada: Ansel Elgort & Dane DeHaan Star in <em>L’Express Styles</em> Shoot<br>Rock the Boat: Tony Ward Ventures Outdoors for <em>L’Optimum Thailand</em><br>COS Makes a Case for Sleek Casualwear with Fall Studio Collection<br>Slate & Stone Takes to Downtown New York for Fall Campaign<br>Jordan Barrett Mixes It Up with Pepe Jeans for Fall Campaign</p> <span id="tve_leads_end_content" style="display: block; visibility: hidden; border: 1px solid transparent;"></span><div class="sharedaddy sd-sharing-enabled"><div class="robots-nocontent sd-block sd-social sd-social-official sd-sharing"><h3 class="sd-title">Share this:</h3><div class="sd-content"><ul><li class="share-facebook"><div class="fb-share-button" data-href="" 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