scholarly journals 14C Ages of a Varved Last Glacial Maximum Section Off Pakistan

Radiocarbon ◽  
2003 ◽  
Vol 45 (3) ◽  
pp. 467-477 ◽  
Author(s):  
Ulrich von Rad ◽  
Michael Sarnthein ◽  
Pieter M Grootes ◽  
Heidi Doose-Rolinski ◽  
Jochen Erbacher
Keyword(s):  
Mass Spectrometry ◽  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Accelerator Mass Spectrometry ◽  
Ice Core ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Oxygen Isotope Record ◽  
Isotope Record

In a core off Pakistan, we obtained 38 14C analyses by accelerator mass spectrometry (AMS) from a 4.4-m-thick, expanded, annually-laminated Last Glacial Maximum (LGM) section, bracketed by bioturbated intervals ascribed to the Heinrich-1 (H1) and Heinrich-2 (H2) equivalent events (52 14C analyses between 24–15 kyr BP). A floating varve age scale, anchored to the oxygen isotope record of the layer-counted GISP2 ice core at the H2/LGM boundary, results in an annually dated record for the LGM from 23,450–17,900 cal BP. The floating varve scale of the LGM provides us with a tentative calibration of local marine AMS 14C age dates to calendar years.

Controlling factors on a paleo-lake oxygen isotope record (Yammoûneh, Lebanon) since the Last Glacial Maximum

2010 ◽  
Vol 29 (7-8) ◽  
pp. 865-886 ◽  
Author(s):  
Anne-Lise Develle ◽  
Julien Herreros ◽  
Laurence Vidal ◽  
Alexandre Sursock ◽  
Françoise Gasse
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Controlling Factors ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Oxygen Isotope Record ◽  
Isotope Record ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Direct dating of the oxygen-isotope record of the last deglaciation by 14C accelerator mass spectrometry

Nature ◽  
1986 ◽  
Vol 320 (6060) ◽  
pp. 350-352 ◽  
Author(s):  
Jean-Claude Duplessy ◽  
Maurice Arnold ◽  
Pierre Maurice ◽  
Edouard Bard ◽  
Josette Duprat ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Oxygen Isotope ◽  
Accelerator Mass Spectrometry ◽  
Last Deglaciation ◽  
Oxygen Isotope Record ◽  
Isotope Record ◽  
The Last Deglaciation

scholarly journals Constituent elements of insoluble and non-volatile particles during the Last Glacial Maximum exhibited in the Dome Fuji (Antarctica) ice core

2009 ◽  
Vol 55 (191) ◽  
pp. 552-562 ◽  
Author(s):  
Yoshinori Iizuka ◽  
Takayuki Miyake ◽  
Motohiro Hirabayashi ◽  
Toshitaka Suzuki ◽  
Sumito Matoba ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Calcium Ion ◽  
Ice Core ◽  
Ice Cores ◽  
Glacial Maximum ◽  
Ion Concentrations ◽  
Last Glacial ◽  
Insoluble Particles ◽  
Almost All ◽  
Constituent Elements

AbstractIn order to find environmental signals based on the dust and calcium-ion concentrations in ice cores, we determine the constituent elements of residue particles obtained after melting ice samples. We have designed a sublimating system that operates at −45°C, below the eutectic temperatures of major salts. This system permits us to obtain a great many non-volatile particles. After studying the non-volatile particles, we immersed them in water to remove soluble particles and compounds. We thereby analyzed a total of 1272 residue particles (from the melted sample), 2418 non-volatile particles (after sublimation) and 1463 insoluble particles taken from five sections of Last Glacial Maximum ice from the Dome Fuji (Antarctica) ice core. Their constituent elements were determined by scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDS) and compared to the dust, calcium-ion and sodium-ion concentrations measured by ion chromatography. Our results indicate that >99.9% of the insoluble particles contain silicon but no sulfur, nitrogen or chlorine. A significant number of the non-volatile particles, however, contain sulfur and chlorine. We conclude that insoluble dust consists mostly of silicate, that almost all calcium ions originate from calcium sulfate and that almost all sodium ions originate from sodium sulfate and sodium chloride.

scholarly journals A 3500-Year Ice Chemistry Record From The Dominion Range, Antarctica: Linkages Between Climatic Variations and Precipitation Chemistry

1990 ◽  
Vol 14 ◽  
pp. 358-358
Author(s):  
Mary Jo Spencer ◽  
Paul A. Mayewski ◽  
W. Berry Lyons ◽  
Mark S. Twickler ◽  
Pieter Grootes
Keyword(s):  
Oxygen Isotope ◽  
Global Climate ◽  
Ice Core ◽  
Precipitation Chemistry ◽  
Climate Forcing ◽  
Climatic Forcing ◽  
Climatic Variations ◽  
Oxygen Isotope Record ◽  
Isotope Record

In 1984 a 200-m ice core was collected from a local accumulation basin in the Dominion Range, Transantarctic Mountains, Antarctica. A complete oxygen isotope record has been obtained and a considerable portion of the core has been analyzed in detail for chloride, nitrate, sulfate, and sodium. About half of the chloride is due to sea salt with the remainder originating as gaseous HCl. Nitrate levels have increased markedly over the last 1000 years whereas the levels of the other constituents have remained fairly constant.The oxygen isotope results suggest that this region of Antarctica is responding to long-term global climate forcing as well as to shorter-term climatic variations. This data will be compared with the anion and sodium records in order to determine the effects of climatic forcing on these other records. In particular, nitrate appears to vary in concert with fluctuations in long-term climate. Additionally, variations in each constituent over the 3500 year period will be examined in detail to determine the influence of other processes which affect their concentrations.

scholarly journals Global Speleothem Oxygen Isotope Measurements Since the Last Glacial Maximum

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
A. M. Shah ◽  
C. Morrill ◽  
E. P. Gille ◽  
W. S. Gross ◽  
D. M. Anderson ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Large Scale ◽  
Asian Summer Monsoon ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Hydrologic Variability ◽  
The World ◽  
The Last Glacial Maximum ◽  
The Last Glacial

This synthesis of thirty-six sites (sixty cores with over 27 000 measurements) located around the world facilitates scientific research on the climate of the last 21 000 years ago obtained from oxygen isotope ( or delta-O-18) measurements. Oxygen isotopes in speleothem calcite record the influence of ambient temperature and the isotopic composition of the source water, the latter providing evidence of hydrologic variability and change. Compared to paleoclimate proxies from sedimentary archives, the age uncertainty is unusually small, around +/−100 years for the last 21 000-year interval. Using data contributed to the World Data Center (WDC) for Paleoclimatology, we have created consistently formatted data files for individual sites as well as composite dataset of annual to millennial resolution. These individual files also contain the chronology information about the sites. The data are useful in understanding hydrologic variability at local and regional scales, such as the Asian summer monsoon and the Intertropical Convergence Zone (as discussed in the underlying source publications), and should also be useful in understanding large-scale aspects of hydrologic change since the Last Glacial Maximum (LGM).

Oxygen isotope stage 3 fluvial and eolian successions in Europe compared with climate model results

2003 ◽  
Vol 59 (2) ◽  
pp. 223-233 ◽  
Author(s):  
K.o van Huissteden ◽  
David Pollard
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Climate Model ◽  
Regional Climate ◽  
Glacial Maximum ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Wind Speeds ◽  
Fluvial Response ◽  
Eolian Deposits

AbstractFluvial and eolian successions of oxygen isotope stage 3 are compared with global (GCM) and regional climate (RCM) modeling experiments of the stage 3 and last glacial maximum climate in Europe. Differences in precipitation between stage-3 stades and interstades were minor, which is confirmed by the fluvial successions. The fluvial response to climate variation is non-uniform, and in southern Europe more pronounced than in northern Europe. The model simulations indicate a strong western winter circulation over Europe during stage 3, which is supported by the eolian deposits data. Wind speeds in the last glacial maximum simulation appear modest compared with those of stage 3, which contrasts with the abundance of eolian deposits. This suggests that during glacial climates the stabilizing effect of vegetation determines eolian sedimentation rates, rather than wind speed. Stage 3 can be divided into an older part (>45,000 cal yr B.P.) with a relatively stable landscape and moist climate and a younger part with more frequent climate change and decreasing landscape stability.

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