scholarly journals Late Weichselian history of relative sea level changes in Iceland during a collapse and subsequent retreat of marine based ice sheet

2015 ◽  
Vol 41 (2) ◽  
pp. 261 ◽  
Author(s):  
H.G. Pétursson ◽  
H. Norðdahl ◽  
Ó. Ingólfsson
Keyword(s):  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
History Of ◽  
Late Weichselian

Late Weichselian relative sea-level changes and ice sheet history in southeast Greenland

2008 ◽  
Vol 272 (1-2) ◽  
pp. 8-18 ◽  
Author(s):  
Antony J. Long ◽  
David H. Roberts ◽  
Matthew J.R. Simpson ◽  
Sue Dawson ◽  
Glenn A. Milne ◽  
...  
Keyword(s):  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Late Weichselian

scholarly journals Antarctic Ice-Sheet Volume at 18000 Years B.P. and Holocene Sea-Level Changes at the West Antarctic Margin

1979 ◽  
Vol 24 (90) ◽  
pp. 213-230 ◽  
Author(s):  
Craig S. Lingle ◽  
James A. Clark
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Changes ◽  
Ice Shelf ◽  
Relative Sea Level ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
The Antarctic

AbstractThe Antarctic ice sheet has been reconstructed at 18000 years b.p. by Hughes and others (in press) using an ice-flow model. The volume of the portion of this reconstruction which contributed to a rise of post-glacial eustatic sea-level has been calculated and found to be (9.8±1.5) × 106 km3. This volume is equivalent to 25±4 m of eustatic sea-level rise, defined as the volume of water added to the ocean divided by ocean area. The total volume of the reconstructed Antarctic ice sheet was found to be (37±6) × 106 km3. If the results of Hughes and others are correct, Antarctica was the second largest contributor to post-glacial eustatic sea-level rise after the Laurentide ice sheet. The Farrell and Clark (1976) model for computation of the relative sea-level changes caused by changes in ice and water loading on a visco-elastic Earth has been applied to the ice-sheet reconstruction, and the results have been combined with the changes in relative sea-level caused by Northern Hemisphere deglaciation as previously calculated by Clark and others (1978). Three families of curves have been compiled, showing calculated relative sea-level change at different times near the margin of the possibly unstable West Antarctic ice sheet in the Ross Sea, Pine Island Bay, and the Weddell Sea. The curves suggest that the West Antarctic ice sheet remained grounded to the edge of the continental shelf until c. 13000 years b.p., when the rate of sea-level rise due to northern ice disintegration became sufficient to dominate emergence near the margin predicted otherwise to have been caused by shrinkage of the Antarctic ice mass. In addition, the curves suggest that falling relative sea-levels played a significant role in slowing and, perhaps, reversing retreat when grounding lines approached their present positions in the Ross and Weddell Seas. A predicted fall of relative sea-level beneath the central Ross Ice Shelf of as much as 23 m during the past 2000 years is found to be compatible with recent field evidence that the ice shelf is thickening in the south-east quadrant.

PISM paleo simulations of the Antarctic Ice Sheet over the last two glacial cycles

2020 ◽  
Author(s):  
Torsten Albrecht ◽  
Ricarda Winkelmann ◽  
Anders Levermann
Keyword(s):  
Boundary Conditions ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Changes ◽  
Glacial Cycles ◽  
Antarctic Ice Sheet ◽  
History Of ◽  
Global Sea Level ◽  
Glacial Time ◽  
The Antarctic

<p>Simulations of the glacial-interglacial history of the Antarctic Ice Sheet provide insights into dynamic threshold behavior and estimates of the ice sheet's contributions to global sea-level changes, for the past, present and future. However, boundary conditions are weakly constrained, in particular at the interface of the ice-sheet and the bedrock. We use the Parallel Ice Sheet Model (PISM) to investigate the dynamic effects of different choices of input data and of various parameterizations on the sea-level relevant ice volume. We evaluate the model's transient sensitivity to corresponding parameter choices and to different boundary conditions over the last two glacial cycles and provide estimates of involved uncertainties. We also present isolated and combined effects of climate and sea-level forcing on glacial time scales. </p>

New observations on the relative sea level and deglacial history of Greenland from Innaarsuit, Disko Bugt

2003 ◽  
Vol 60 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Antony J. Long ◽  
David H. Roberts ◽  
Morten Rasch
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Ice Sheet ◽  
The South ◽  
Relative Sea Level ◽  
West Greenland ◽  
History Of ◽  
A Site ◽  
Marine Embayment

AbstractRelative sea level (RSL) data derived from isolation basins at Innaarsuit, a site on the south shores of the large marine embayment of Disko Bugt, West Greenland, record rapid RSL fall from the marine limit (ca. 108 m) at 10,300–9900 cal yr B.P. to reach the present sea level at 3500 cal yr B.P. Since 2000 cal yr B.P., RSL rose ca. 3 m to the present. When compared with data from elsewhere in Disko Bugt, our results suggest that the embayment was deglaciated later and more quickly than previously thought, at or slightly before 10,300 cal yr B.P. The northern part of Disko Bugt experienced less rebound (ca. 10 m at 6000 cal yr B.P.) compared with areas to the south. Submergence during the late Holocene supports a model of crustal down-warping as a result of renewed ice-sheet growth during the neoglacial. There is little evidence for west to east differences in crustal rebound across the southern shores of Disko Bugt.

Late Weichselian and Holocene Relative Sea-level History of Bröggerhalvöya, Spitsbergen

1987 ◽  
Vol 27 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Steven L. Forman ◽  
Daniel H. Mann ◽  
Gifford H. Miller
Keyword(s):  
Sea Level ◽  
Barents Sea ◽  
Relative Sea Level ◽  
Norwegian Sea ◽  
Depositional Processes ◽  
Before And After ◽  
History Of ◽  
Ice Conditions ◽  
Late Weichselian ◽  
Raised Beaches

AbstractRadiocarbon-dated whalebones from raised beaches record a relative sea-level history for Bröggerhalvöya, western Spitsbergen that suggest a two-step deglaciation on Svalbard at the end of the late Weichselian glaciation. The late Weichselian marine limit was reached at about 13,000 yr B.P. and was followed by relatively slow emergence until about 10,000 yr B.P. either in response to ice unloading in the Barents Sea, initial retreat of local fjord glaciers, or some combination of the two. Rare whale skeletons dating between 13,000 and 10,000 yr B.P. indicate that the Norwegian Sea was at least seasonally ice free during that interval. Deglaciation of Spitsbergen is recorded by the rapid emergence of Bröggerhalvöya after 10,000 yr B.P. This was followed by a transgression during the mid-Holocene, here named the Talavera Transgression, and another in modern times. Raised beach morphologies suggest striking differences in nearshore depositional processes before and after 10,000 yr B.P. that are probably related to changes in the rate of uplift and in sea-ice conditions.

scholarly journals Antarctic Ice-Sheet Volume at 18000 Years B.P. and Holocene Sea-Level Changes at the West Antarctic Margin

1979 ◽  
Vol 24 (90) ◽  
pp. 213-230 ◽  
Author(s):  
Craig S. Lingle ◽  
James A. Clark
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Changes ◽  
Ice Shelf ◽  
Relative Sea Level ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
The Antarctic

AbstractThe Antarctic ice sheet has been reconstructed at 18000 years b.p. by Hughes and others (in press) using an ice-flow model. The volume of the portion of this reconstruction which contributed to a rise of post-glacial eustatic sea-level has been calculated and found to be (9.8±1.5) × 106km3. This volume is equivalent to 25±4 m of eustatic sea-level rise, defined as the volume of water added to the ocean divided by ocean area. The total volume of the reconstructed Antarctic ice sheet was found to be (37±6) × 106km3. If the results of Hughes and others are correct, Antarctica was the second largest contributor to post-glacial eustatic sea-level rise after the Laurentide ice sheet. The Farrell and Clark (1976) model for computation of the relative sea-level changes caused by changes in ice and water loading on a visco-elastic Earth has been applied to the ice-sheet reconstruction, and the results have been combined with the changes in relative sea-level caused by Northern Hemisphere deglaciation as previously calculated by Clark and others (1978). Three families of curves have been compiled, showing calculated relative sea-level change at different times near the margin of the possibly unstable West Antarctic ice sheet in the Ross Sea, Pine Island Bay, and the Weddell Sea. The curves suggest that the West Antarctic ice sheet remained grounded to the edge of the continental shelf untilc. 13000 years b.p., when the rate of sea-level rise due to northern ice disintegration became sufficient to dominate emergence near the margin predicted otherwise to have been caused by shrinkage of the Antarctic ice mass. In addition, the curves suggest that falling relative sea-levels played a significant role in slowing and, perhaps, reversing retreat when grounding lines approached their present positions in the Ross and Weddell Seas. A predicted fall of relative sea-level beneath the central Ross Ice Shelf of as much as 23 m during the past 2000 years is found to be compatible with recent field evidence that the ice shelf is thickening in the south-east quadrant.

scholarly journals Depositional environment of the Branch Sandstone and correlative sequences: Late Cretaceous changes in relative sea level in the East Coast Basin of New Zealand

2021 ◽  
Author(s):  
◽  
Lisa McCarthy
Keyword(s):  
Sea Level ◽  
East Coast ◽  
Depositional Environments ◽  
Passive Margin ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Level Fluctuations ◽  
The North ◽  
Tasman Sea ◽  
History Of

<p>The Branch Sandstone is located within an overall transgressive, marine sedimentary succession in Marlborough, on the East Coast of New Zealand’s South Island. It has previously been interpreted as an anomalous sedimentary unit that was inferred to indicate abrupt and dramatic shallowing. The development of a presumed short-lived regressive deposit was thought to reflect a change in relative sea level, which had significant implications for the geological history of the Marlborough region, and regionally for the East Coast Basin.  The distribution and lithology of Branch Sandstone is described in detail from outcrop studies at Branch Stream, and through the compilation of existing regional data. Two approximately correlative sections from the East Coast of the North Island (Tangaruhe Stream and Angora Stream) are also examined to provide regional context. Depositional environments were interpreted using sedimentology and palynology, and age control was developed from dinoflagellate biostratigraphy. Data derived from these methods were combined with the work of previous authors to establish depositional models for each section which were then interpreted in the context of relative sea level fluctuations.  At Branch Stream, Branch Sandstone is interpreted as a shelfal marine sandstone, that disconformably overlies Herring Formation. The Branch Sandstone is interpreted as a more distal deposit than uppermost Herring Formation, whilst the disconformity is suggested to have developed during a fall in relative sea level. At Branch Stream, higher frequency tectonic or eustatic sea-level changes can therefore be distinguished within a passive margin sedimentary sequence, where sedimentation broadly reflects subsidence following rifting of the Tasman Sea. Development of a long-lived disconformity at Tangaruhe Stream and deposition of sediment gravity flow deposits at Angora Stream occurred at similar times to the fall in relative sea level documented at the top of the Herring Formation at Branch Stream. These features may reflect a basin-wide relative sea-level event, that coincides with global records of eustatic sea level fall.</p>

Bias in Estimates of Global Mean Sea Level Change Inferred from Satellite Altimetry

2018 ◽  
Vol 31 (13) ◽  
pp. 5263-5271 ◽  
Author(s):  
Megan Jeramaz Lickley ◽  
Carling C. Hay ◽  
Mark E. Tamisiea ◽  
Jerry X. Mitrovica
Keyword(s):  
Sea Level ◽  
Mass Flux ◽  
Satellite Altimetry ◽  
Ice Sheet ◽  
Sea Level Change ◽  
Global Ocean ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Level Change ◽  
The Antarctic

Estimates of regional and global average sea level change remain a focus of climate change research. One complication in obtaining coherent estimates is that geodetic datasets measure different aspects of the sea level field. Satellite altimetry constrains changes in the sea surface height (SSH; or absolute sea level), whereas tide gauge data provide a measure of changes in SSH relative to the crust (i.e., relative sea level). The latter is a direct measure of changes in ocean volume (and the combined impacts of ice sheet melt and steric effects), but the former is not since it does not account for crustal deformation. Nevertheless, the literature commonly conflates the two estimates by directly comparing them. We demonstrate that using satellite altimetry records to estimate global ocean volume changes can lead to biases that can exceed 15%. The level of bias will depend on the relative contributions to sea level changes from the Antarctic and Greenland Ice Sheets. The bias is also more sensitive to the detailed geometry of mass flux from the Antarctic Ice Sheet than the Greenland Ice Sheet due to rotational effects on sea level. Finally, in a regional sense, altimetry estimates should not be compared to relative sea level changes because radial crustal motions driven by polar ice mass flux are nonnegligible globally.

Lower Silurian reefs and post-reef beds of the Attawapiskat Formation, Hudson Bay Platform, northern Ontario

1993 ◽  
Vol 30 (3) ◽  
pp. 575-590 ◽  
Author(s):  
Daniel R. Suchy ◽  
Colin W. Stearn
Keyword(s):  
Debris Flow ◽  
Sea Level ◽  
Hudson Bay ◽  
Burial Diagenesis ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Northern Ontario ◽  
Sea Level Fluctuations ◽  
Wide Range ◽  
History Of

Outcrop exposures along the Attawapiskat River in the Hudson Bay Lowlands of northern Ontario clearly reveal the morphology of Silurian (upper Llandoverian) reefs of the Attawapiskat Formation and the relationships between reef cores, flanking beds, and post-reef beds. These relationships indicate that the reefs had a syndepositional relief of at least 8–10 m. The relief of the reefs is indicated by debris-flow lenses encased within flanking beds, a debris-flow fan at the base of a reef, thin reef-flanking beds truncated against a vertical reef face, penecontemporaneous brachiopod beds on the flanks of reefs, and three large slide blocks that apparently slid over the side of a reef.Reefs of the Attawapiskat Formation are largely limestones with a wide range of lithologies, from stromatoporoid-, coral-, and cement-rich boundstones to alga–cement-rich boundstones. Thick, laterally extensive Nuia grainstone beds, a product of widespread Nuia monocultures in supratidal to intertidal ponds, are present above the reefs. The most important diagenetic processes were early marine cementation (predominantly radial-fibrous calcite), shallow burial diagenesis, and pervasive neomorphism.Schematic reconstructions of the depositional history of the Attawapiskat Formation in outcrop, constructed from observations of outcrop relationships, show a stratigraphic succession that was controlled by relative-sea-level changes. Reefs growth was terminated by a relative-sea-level fall, but subsequent minor relative-sea-level fluctuations resulted in alternating deposition of supratidal to shallow subtidal sediments for a short time before the final retreat of the Silurian seas from the Hudson Bay Platform; only supratidal evaporite facies are present in the remainder of the Silurian section above the Attawapiskat Formation.

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