Reconstruction of the Holocene seismic history of a seabed fault using relative sea-level curves reconstructed by ostracode assemblages: Case study on the Median Tectonic Line in Iyo-nada Bay, western Japan

2005 ◽  
Vol 222 (3-4) ◽  
pp. 285-312 ◽  
Author(s):  
Moriaki Yasuhara ◽  
Shusaku Yoshikawa ◽  
Futoshi Nanayama
Keyword(s):  
Sea Level ◽  
Relative Sea Level ◽  
The Holocene ◽  
Level Curves ◽  
Median Tectonic Line ◽  
History Of ◽  
Western Japan ◽  
Tectonic Line

Mid-Cretaceous onlap history of the Market Weighton structural high, northeast England

1999 ◽  
Vol 136 (6) ◽  
pp. 681-696 ◽  
Author(s):  
C. J. UNDERWOOD ◽  
S. F. MITCHELL
Keyword(s):  
Sea Level ◽  
High Frequency ◽  
Sedimentary Facies ◽  
Relative Sea Level ◽  
Western Margin ◽  
Level Curves ◽  
History Of ◽  
Tectonic Settings ◽  
Global Sea Level ◽  
Structural High

The mid-Cretaceous sediments of northeast England were deposited at the western margin of the southern North Sea Basin, with sedimentation occurring in a range of tectonic settings. Detailed analysis of the areal distribution and sedimentary facies of Aptian to earliest Cenomanian sediments has allowed the pattern of onlap onto the Market Weighton structural high and changes in relative sea level to be documented. Successive onlap episodes during the Early Aptian, Late Aptian and Early Albian culminated in the final flooding of the structure during the Late Albian (varicosum Subzone). Sea-level curves generated from coastal onlap patterns are difficult to relate to published ‘global’ sea-level curves due to the high frequency of the fluctuations in relative sea level observed. Despite this, detailed correlation and analysis of sedimentological events suggest that even the most expanded, basinal succession is relatively incomplete. This study has also shown that the change from dominantly syn-tectonic to dominantly post-tectonic sedimentation style occurred in the late Early Albian.

Holocene sea-level history of the Canadian Beaufort shelf

1993 ◽  
Vol 30 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Philip R. Hill ◽  
Arnaud Héquette ◽  
Marie-Hélène Ruz
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Marine Sediments ◽  
Tidal Marsh ◽  
Relative Sea Level ◽  
The Holocene ◽  
Single Piece ◽  
History Of ◽  
Holocene Sea Level

New radiocarbon ages pertaining to the Holocene sea-level history of the Canadian Beaufort shelf are presented. The ages were obtained on samples of freshwater and tidal-marsh peat beds from offshore boreholes and shallow cores in the coastal zone and on molluscs and a single piece of wood deposited in foraminifera-bearing marine sediments. Although none of the samples record directly the position of relative sea level, the suite of ages constrains the regional curve sufficiently to suggest a faster rate of mid Holocene sea level rise (7–14 mm/a) than previously thought. The rate of relative rise slowed markedly in the last 3000 years, approaching the present at a maximum probable rate of 2.5 mm/a.

Isostatic adjustments in a full glacial sea

1983 ◽  
Vol 20 (6) ◽  
pp. 895-917 ◽  
Author(s):  
John England
Keyword(s):  
Sea Level ◽  
Ellesmere Island ◽  
Relative Sea Level ◽  
Level Curves ◽  
Last Glaciation ◽  
Isostatic Equilibrium ◽  
Paleoclimatic Changes ◽  
History Of ◽  
Rapid Emergence

During the last glaciation an ice-free corridor existed between the northeast Ellesmere Island and northwest Greenland ice sheets. This corridor constituted a peripheral depression in which the marine limit marks the uppermost extent of a full glacial sea. The full glacial sea is characterized by (1) 14C dates on in situ marine shells that predate initial emergence (unloading) followed by (2) synchronous emergence from the marine limit throughout the peripheral depression. Relative sea-level curves from the full glacial sea confirm previous morphostratigraphic and glacioisostatic evidence for limited ice extent during the last glaciation. These curves also document the history of glacial unloading and the form of the relative sea-level curve that one would theoretically expect in the peripheral depression. The form of the curves presented here is unlike any other published emergence curves from arctic Canada or from Fennoscandia.The relative sea-level curves for northeast Ellesmere Island show three segments: (1) an interval of stable relative sea level (isostatic equilibrium) at the marine limit between at least 11 000 and 8000 BP; (2) an interval of slow emergence from 8000 to 6200 BP during which northeast Ellesmere Island ice slowly retreated; and (3) an interval of rapid emergence, caused by rapid glacial unloading, after 6200 BP when a prominent amelioration was in progress. These relative sea-level curves are discussed in relation to other paleoclimatic changes and the deglacial history of northwest Greenland. These curves are of regional importance in that they provide a new means of distinguishing between areas that were ice covered and ice free during the last glaciation.

Palaeoenvironmental significance of a large-scale buried ice-marginal landsystem, Skeiðarársandur, SE Iceland

2021 ◽  
Author(s):  
Devin Harrison ◽  
Neil Ross ◽  
Andrew J. Russell ◽  
Stuart J. Jones
Keyword(s):  
Surface Morphology ◽  
Environmental History ◽  
Sea Level ◽  
Ice Age ◽  
Glacial History ◽  
Relative Sea Level ◽  
The Holocene ◽  
Geophysical Surveys ◽  
History Of ◽  
Dip Angle

<p>The sedimentary record of Icelandic ice-contact environments provides valuable information about glacier margin dynamics and position, relative sea-level, and the geomorphic processes that drive the evolution of proglacial environments. This important archive has been little exploited, however, with most glacier and sea level reconstructions based on limited sedimentary exposures and surface geomorphic evidence. Although geophysical surveys of Icelandic sandur have been conducted, they have often been of limited spatial scale and focus on specific landforms. We report an extensive (42 km of data within a 24 km<sup>2 </sup>study area) and detailed (reflections recorded at depths of up to 100 m) low-frequency (40 and 100 MHz) Ground-Penetrating Radar (GPR) survey of the Sandgígur moraine complex, SE Iceland. This transforms our understanding of this landform, with implications for the Holocene glacial history and evolution of Skeiðarársandur and SE Iceland.</p><p>The Sandgígur moraines are located on Skeiðarársandur, SE Iceland, down-sandur of large Little Ice Age-moraines of Skeiðarárjökull. They have a relatively subtle surface geomorphic expression (typically 7 m high and 125 m wide), and knowledge of their formation is limited, with no dating control on their age or detailed geomorphic or sedimentological investigations. GPR-data reveals reflections interpreted as large progradational foresets (dip angle: 2.19° – 6.87°) beneath the morainic structure (depth of 100 m). These features are consistent with a sub-aqueous depositional environment before moraine formation, providing potential indications of past relative sea-level limits. GPR profiles in the vicinity of the Sandgígur moraines reveal a much larger (67 m high and 1.25 km wide) and extensive buried moraine complex than that suggested by surface morphology. Indicating that the moraine was a major Holocene ice margin of Skeiðarárjökull. The buried Sandgígur moraine ridge is comprised of a unit of chaotic folded reflections adjacent to a unit of parallel, down-sandur dipping reflections (dip angle: 1.29° – 2.27°) indicative of an ice-contact or end-moraine fan. Possible evidence of buried ice at depth is also present within radargrams surrounding the moraine ridges. Sediment above the morainic bounding surface is interpreted to be dominated by glaciofluvial deposits with an estimated sediment volume of 1.04 km<sup>3</sup> over the 24 km<sup>2</sup> study area. Potential moraine breaches, possibly caused by high magnitude jökulhlaups (glacier outburst floods) are coincident within the GPR data and the surface geomorphology.</p><p>We combine GPR-derived subsurface architecture with the current surface morphology to develop a conceptual model detailing the geomorphic evolution of the moraines and surrounding region, from pre-moraine morphology, to their formation and burial, resulting in the present-day morphology. These results provide new insights into the Holocene to present-day glacial history of Skeiðarárjökull and the controls on sedimentation responsible for the evolution of Skeiðarársandur, with implications for the formation of sandar environments and the Holocene environmental history of SE Iceland.</p>

Relative sea level changes during the Holocene in the Sisimiut area, south-western Greenland

2011 ◽  
Vol 26 (4) ◽  
pp. 353-361 ◽  
Author(s):  
Ole Bennike ◽  
Bernd Wagner ◽  
Andreas Richter
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
The Holocene

scholarly journals Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern Brazil

2014 ◽  
Vol 86 (2) ◽  
pp. 671-683 ◽  
Author(s):  
JOÃO WAGNER A. CASTRO ◽  
KENITIRO SUGUIO ◽  
JOSÉ C.S. SEOANE ◽  
ALINE M. DA CUNHA ◽  
FABIO F. DIAS
Keyword(s):  
Sea Level ◽  
Rio De Janeiro ◽  
Atlantic Coast ◽  
Southeastern Brazil ◽  
Brazilian Coast ◽  
14C Dating ◽  
Relative Sea Level ◽  
Coastal Evolution ◽  
The Holocene ◽  
First Time

The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops, we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere along the Atlantic coast of South America. The results of this study are consistent with previous researches and they help to refine the Holocene sea-level record along the Brazilian coast.

scholarly journals New relative sea-level insights into the isostatic history of the Western Mediterranean

2018 ◽  
Vol 201 ◽  
pp. 396-408 ◽  
Author(s):  
Matteo Vacchi ◽  
Matthieu Ghilardi ◽  
Rita T. Melis ◽  
Giorgio Spada ◽  
Matthieu Giaime ◽  
...  
Keyword(s):  
Sea Level ◽  
Western Mediterranean ◽  
Relative Sea Level ◽  
History Of

scholarly journals Lack of marine entry into Marmara and Black Sea-lakes indicate low relative sea level during MIS 3 in the northeastern Mediterranean

2019 ◽  
Author(s):  
Anastasia G. Yanchilina ◽  
Celine Grall ◽  
William B. F. Ryan ◽  
Jerry F. McManus ◽  
Candace O. Major
Keyword(s):  
Sea Level ◽  
Black Sea ◽  
Global Ocean ◽  
The Black Sea ◽  
Marmara Sea ◽  
Independent Data ◽  
Relative Sea Level ◽  
Mis 3 ◽  
History Of ◽  
Marine Isotope Stage 3

Abstract. The Marine Isotope Stage 3 (MIS 3) is considered a period of persistent and rapid climate and sea level variabilities during which eustatic sea level is observed to have varied by tens of meters. Constraints on local sea level during this time are critical for further estimates of these variabilities. We here present constraints on relative sea level in the Marmara and Black Sea regions in the northeastern Mediterranean, inferred from reconstructions of the history of the connections and disconnections (partial or total) of these seas together with the global ocean. We use a set of independent data from seismic imaging and core-analyses to infer that the Marmara and Black Seas remained connected persistent freshwater lakes that outflowed to the global ocean during the majority of MIS 3. Marine water intrusion during the early MIS-3 stage may have occurred into the Marmara Sea-Lake but not the Black Sea-Lake. This suggests that the relative sea level was near the paleo-elevation of the Bosporus sill and possibly slightly above the Dardanelles paleo-elevation, ~80 mbsl. The Eustatic sea level may have been even lower, considering the isostatic effects of the Eurasian ice sheet would have locally uplifted the topography of the northeastern Mediterrranean.

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