Anne E Jennings
Biographic Data
| ID | 8551935 |
|---|---|
| NAME | Anne E Jennings |
| GIVEN NAMES | Anne E |
| FAMILY NAME | Jennings |
| SIGNATURE | JENNINGS A E |
| AFFILIATIONS | Department of Geological Sciences, University of Colorado, Boulder, CO 80309-0450, USA |
| VERIFIED | No |
| TOTAL WORKS | 11 |
| TOTAL CITATIONS | 36 |
| AUTHOR COUNT | 11 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1996 |
| LATEST PUBLICATION YEAR | 2018 |
| H-INDEX | 4 |
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores
The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marine-terminating outlet glaciers, which lose mass through increases in calving, submarine melting and terrestrial meltwater discharge. In terms of iceberg production, Jakobshavn Isbræ is the largest marine-terminating glacier in Greenland, yet relatively little is known about its history before the fir…
Holocene Mg/Ca, alkenones, and light stable isotope measurements on the outer North Iceland shelf (MD99-2269)
To evaluate whether proxies that record surface, near-surface, and bottom water conditions from the North Iceland shelf have similar trends and periodicities, we examine Holocene century-scale paleoceanographic records from core MD99-2269. This core site lies close to the boundary between Atlantic and Arctic/Polar waters, and in an area frequently influenced by drift ice. The proxies are stable δ 13 C and δ 18 O values on planktonic and benthic f…
Cooling and freshening at 8.2 ka on the NW Iceland Shelf recorded in paired δ 18 O and Mg/Ca measurements of the benthic foraminifer Cibicides lobatulus
A shallow marine sediment core from NW Iceland provides evidence for a brief cooling and freshening at ~ 8200 cal yr BP, consistent with the hypothesis that the catastrophic outburst flood of the proglacial lakes Oijbway and Agassiz caused the 8.2 ka event. This is the first high-resolution record reconstructing near-surface temperatures and δ 18 O sw by paired measurements of Mg/Ca and δ 18 O calcite of a benthic foraminifer. We developed a new …
A robust, multisite Holocene history of drift ice off northern Iceland
An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative x-ray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quar…
Geochemistry of Holocene cryptotephras from the North Iceland Shelf (MD99-2269)
Tephra-grain counting, morphology and geochemistry in the 150–1000 μm size fraction were used to identify 22 individual tephra horizons and one visible tephra layer (Saksunarvatn) from postglacial sediment of the north Iceland shelf. Core MD99-2269 (66°37.53‘N, 20°51.16‘W, water depth 365 m, length 2533 cm) from the Reykjafjardaráll basin is constrained at the base by the Vedde tephra (c. 12 000 cal. yr BP). Geochemical analyses and stratigraphic…
Accumulation in East Greenland Fjords and on the Continental Shelves Adjacent to the Denmark Strait over the Last Century Based on 210Pb Geochronology
Sediment (SAR) and mass (MAR) accumulation rates for the last 100 years are derived from 210Pb profiles of box cores collected in three fjords and on the continental shelf in the Kangerlussuaq region, East Greenland, and on the SW Iceland continental shelf. The MAR is lower on East Greenland (0.09 g/cm2·yr) than on SW Iceland (0.14 g/cm2·yr) because of differences in the biogenic component of the sediments, although SAR is similar. The difference…
A mid-Holocene shift in Arctic sea-ice variability on the East Greenland Shelf
Records of iceberg-rafting and palaeohydrography from two East Greenland shelf cores (JM96-1206/1-GC and JM96-1207/1-GC) are reported. Benthic foraminifera, stable isotopes and IRD fluxes indicate a shift toward colder, lower-salinity ‘polar’ conditions c. 5 cal. ka. A new proxy of iceberg-rafting on the East Greenland Shelf is the flux of calcium carbonate (TIC) thought to be derived from glacial erosion of Cretaceous calcareous mudstones. A cha…
Multicentury-Scale Records of Carbonate (Hydrographic?) Variability on the Northern Iceland Margin over the Last 5000 Years
The waters off northern Iceland are subjected to extreme hydrographic variability on annual to decadal timescales. In years when cold low-salinity water moves coastward and sea ice is prevalent (i.e., the late 1960s), marine productivity of surface waters is low because the water column is well stratified. In the opposite oceanographic mode, warm, salty Atlantic Water dominates the shelf and vertical mixing results in high productivity. We track …
Problems and Possible Solutions Concerning Radiocarbon Dating of Surface Marine Sediments, Ross Sea, Antarctica
Radiocarbon accelerator mass spectrometric (AMS) dates on the acid-insoluble fraction from 38 core tops from the western Ross Sea, Antarctica, are used to address these questions: (1) What are the apparent ages of sediments at or close to the present sediment/water interface? (2) Is there a statistically significant pattern to the spatial distribution of core top ages? and (3) Is there a “correction factor” that can be applied to these age determ…
Late Pleistocene-Holocene marine conditions in the Ross Sea, Antarctica
Statistical analyses of diatom assemblages from radiocarbon-dated sediment cores were used to reconstruct changing palaeoceanographic conditions in the western and west-central Ross Sea, Antarctica, from. c.12 14 C kyr BP to the present. Data from three Kasten cores support a north-to-south time-transgressive glacial/interglacial transition. Assemblages at the base of each core suggest that glacial processes affecting frustule preservation were s…
Environmental change in eastern Greenland during the last 1300 years
Lithofacies and benthic foraminiferal analyses of two sediment cores (BS1191-K13B and K14) from Nansen Fjord, eastern Greenland, show evidence of changing oceanographic and sea-ice conditions from AD 730 to the present. Radiocarbon dates on foraminifera provide century-scale resolution of events, but the frequency of events between dated levels can be estimated with a resolution of approximately 4 to 9 years per centimetre of core. Unstratified g…
A mid-Holocene shift in Arctic sea-ice variability on the East Greenland Shelf
Records of iceberg-rafting and palaeohydrography from two East Greenland shelf cores (JM96-1206/1-GC and JM96-1207/1-GC) are reported. Benthic foraminifera, stable isotopes and IRD fluxes indicate a shift toward colder, lower-salinity ‘polar’ conditions c. 5 cal. ka. A new proxy of iceberg-rafting on the East Greenland Shelf is the flux of calcium carbonate (TIC) thought to be derived from glacial erosion of Cretaceous calcareous mudstones. A cha…
Environmental change in eastern Greenland during the last 1300 years
Lithofacies and benthic foraminiferal analyses of two sediment cores (BS1191-K13B and K14) from Nansen Fjord, eastern Greenland, show evidence of changing oceanographic and sea-ice conditions from AD 730 to the present. Radiocarbon dates on foraminifera provide century-scale resolution of events, but the frequency of events between dated levels can be estimated with a resolution of approximately 4 to 9 years per centimetre of core. Unstratified g…
Geochemistry of Holocene cryptotephras from the North Iceland Shelf (MD99-2269)
Tephra-grain counting, morphology and geochemistry in the 150–1000 μm size fraction were used to identify 22 individual tephra horizons and one visible tephra layer (Saksunarvatn) from postglacial sediment of the north Iceland shelf. Core MD99-2269 (66°37.53‘N, 20°51.16‘W, water depth 365 m, length 2533 cm) from the Reykjafjardaráll basin is constrained at the base by the Vedde tephra (c. 12 000 cal. yr BP). Geochemical analyses and stratigraphic…
Late Pleistocene-Holocene marine conditions in the Ross Sea, Antarctica
Statistical analyses of diatom assemblages from radiocarbon-dated sediment cores were used to reconstruct changing palaeoceanographic conditions in the western and west-central Ross Sea, Antarctica, from. c.12 14 C kyr BP to the present. Data from three Kasten cores support a north-to-south time-transgressive glacial/interglacial transition. Assemblages at the base of each core suggest that glacial processes affecting frustule preservation were s…
A robust, multisite Holocene history of drift ice off northern Iceland
An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative x-ray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quar…
Environmental change in eastern Greenland during the last 1300 years
Lithofacies and benthic foraminiferal analyses of two sediment cores (BS1191-K13B and K14) from Nansen Fjord, eastern Greenland, show evidence of changing oceanographic and sea-ice conditions from AD 730 to the present. Radiocarbon dates on foraminifera provide century-scale resolution of events, but the frequency of events between dated levels can be estimated with a resolution of approximately 4 to 9 years per centimetre of core. Unstratified g…
Problems and Possible Solutions Concerning Radiocarbon Dating of Surface Marine Sediments, Ross Sea, Antarctica
Radiocarbon accelerator mass spectrometric (AMS) dates on the acid-insoluble fraction from 38 core tops from the western Ross Sea, Antarctica, are used to address these questions: (1) What are the apparent ages of sediments at or close to the present sediment/water interface? (2) Is there a statistically significant pattern to the spatial distribution of core top ages? and (3) Is there a “correction factor” that can be applied to these age determ…
Late Pleistocene-Holocene marine conditions in the Ross Sea, Antarctica
Statistical analyses of diatom assemblages from radiocarbon-dated sediment cores were used to reconstruct changing palaeoceanographic conditions in the western and west-central Ross Sea, Antarctica, from. c.12 14 C kyr BP to the present. Data from three Kasten cores support a north-to-south time-transgressive glacial/interglacial transition. Assemblages at the base of each core suggest that glacial processes affecting frustule preservation were s…
Multicentury-Scale Records of Carbonate (Hydrographic?) Variability on the Northern Iceland Margin over the Last 5000 Years
The waters off northern Iceland are subjected to extreme hydrographic variability on annual to decadal timescales. In years when cold low-salinity water moves coastward and sea ice is prevalent (i.e., the late 1960s), marine productivity of surface waters is low because the water column is well stratified. In the opposite oceanographic mode, warm, salty Atlantic Water dominates the shelf and vertical mixing results in high productivity. We track …
Accumulation in East Greenland Fjords and on the Continental Shelves Adjacent to the Denmark Strait over the Last Century Based on 210Pb Geochronology
Sediment (SAR) and mass (MAR) accumulation rates for the last 100 years are derived from 210Pb profiles of box cores collected in three fjords and on the continental shelf in the Kangerlussuaq region, East Greenland, and on the SW Iceland continental shelf. The MAR is lower on East Greenland (0.09 g/cm2·yr) than on SW Iceland (0.14 g/cm2·yr) because of differences in the biogenic component of the sediments, although SAR is similar. The difference…
A mid-Holocene shift in Arctic sea-ice variability on the East Greenland Shelf
Records of iceberg-rafting and palaeohydrography from two East Greenland shelf cores (JM96-1206/1-GC and JM96-1207/1-GC) are reported. Benthic foraminifera, stable isotopes and IRD fluxes indicate a shift toward colder, lower-salinity ‘polar’ conditions c. 5 cal. ka. A new proxy of iceberg-rafting on the East Greenland Shelf is the flux of calcium carbonate (TIC) thought to be derived from glacial erosion of Cretaceous calcareous mudstones. A cha…
Geochemistry of Holocene cryptotephras from the North Iceland Shelf (MD99-2269)
Tephra-grain counting, morphology and geochemistry in the 150–1000 μm size fraction were used to identify 22 individual tephra horizons and one visible tephra layer (Saksunarvatn) from postglacial sediment of the north Iceland shelf. Core MD99-2269 (66°37.53‘N, 20°51.16‘W, water depth 365 m, length 2533 cm) from the Reykjafjardaráll basin is constrained at the base by the Vedde tephra (c. 12 000 cal. yr BP). Geochemical analyses and stratigraphic…
A robust, multisite Holocene history of drift ice off northern Iceland
An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative x-ray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quar…
Cooling and freshening at 8.2 ka on the NW Iceland Shelf recorded in paired δ 18 O and Mg/Ca measurements of the benthic foraminifer Cibicides lobatulus
A shallow marine sediment core from NW Iceland provides evidence for a brief cooling and freshening at ~ 8200 cal yr BP, consistent with the hypothesis that the catastrophic outburst flood of the proglacial lakes Oijbway and Agassiz caused the 8.2 ka event. This is the first high-resolution record reconstructing near-surface temperatures and δ 18 O sw by paired measurements of Mg/Ca and δ 18 O calcite of a benthic foraminifer. We developed a new …
Holocene Mg/Ca, alkenones, and light stable isotope measurements on the outer North Iceland shelf (MD99-2269)
To evaluate whether proxies that record surface, near-surface, and bottom water conditions from the North Iceland shelf have similar trends and periodicities, we examine Holocene century-scale paleoceanographic records from core MD99-2269. This core site lies close to the boundary between Atlantic and Arctic/Polar waters, and in an area frequently influenced by drift ice. The proxies are stable δ 13 C and δ 18 O values on planktonic and benthic f…
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores
The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marine-terminating outlet glaciers, which lose mass through increases in calving, submarine melting and terrestrial meltwater discharge. In terms of iceberg production, Jakobshavn Isbræ is the largest marine-terminating glacier in Greenland, yet relatively little is known about its history before the fir…
Geology and Paleoclimatology Research (11 works) · Geology (8 works) · Holocene (7 works) · Methane Hydrates and Related Phenomena (7 works) · Oceanography (7 works) · Paleontology (6 works) · Geography (5 works) · Physical geography (5 works) · Arctic (4 works) · Benthic zone (4 works)