Obrochta, Stephen P. and Crowley, Thomas J. and Channell, James E. T. and Hodell, David A. and Baker, Paul A. and Seki, Arisa and Yokoyama, Yusuke (2014) Climate variability and ice-sheet dynamics during the last three glaciations. Earth and Planetary Science Letters, 406. pp. 198-212. ISSN 0012821X DOI https://doi.org/10.1016/j.epsl.2014.09.004
|
Text
Obrochta et al. - 2014 - Climate variability and ice-sheet dynamics during.pdf - Published Version Available under License Creative Commons Attribution. Download (2MB) | Preview |
|
![]()
|
Image
1-s2.0-S0012821X14005494-gr001.jpg Download (108kB) | Preview |
|
|
Text
mmc1.pdf - Supplemental Material Available under License Creative Commons Attribution. Download (7MB) | Preview |
|
![]() |
Image
mmc2.kml - Supplemental Material Available under License Creative Commons Attribution No Derivatives. Download (11kB) |
Abstract
A composite North Atlantic record from DSDP Site 609 and IODP Site U1308 spans the past 300,000 years and shows that variability within the penultimate glaciation differed substantially from that of the surrounding two glaciations. Hematite-stained grains exhibit similar repetitive down-core variations within the Marine Isotope Stage (MIS) 8 and 4–2 intervals, but little cyclic variability within the MIS 6 section. There is also no petrologic evidence, in terms of detrital carbonate-rich (Heinrich) layers, for surging of the Laurentide Ice Sheet through the Hudson Strait during MIS 6. Rather, very high background concentration of iceberg-rafted debris (IRD) indicates near continuous glacial meltwater input that likely increased thermohaline disruption sensitivity to relatively weak forcing events, such as expanded sea ice over deepwater formation sites. Altered (sub)tropical precipitation patterns and Antarctic warming during high orbital precession and low 65°N summer insolation appear related to high abundance of Icelandic glass shards and southward sea ice expansion. Differing European and North American ice sheet configurations, perhaps aided by larger variations in eccentricity leading to cooler summers, may have contributed to the relative stability of the Laurentide Ice Sheet in the Hudson Strait region during MIS 6.
Item Type: | Article |
---|---|
Additional Information: | Data included in this manuscript are available at http://dx.doi.org/10.1594/PANGAEA.834640 |
Uncontrolled Keywords: | 2014AREP; IA68; |
Subjects: | 01 - Climate Change and Earth-Ocean Atmosphere Systems |
Divisions: | 01 - Climate Change and Earth-Ocean Atmosphere Systems 07 - Gold Open Access |
Journal or Publication Title: | Earth and Planetary Science Letters |
Volume: | 406 |
Page Range: | pp. 198-212 |
Identification Number: | https://doi.org/10.1016/j.epsl.2014.09.004 |
Depositing User: | Sarah Humbert |
Date Deposited: | 06 Feb 2015 17:28 |
Last Modified: | 16 Feb 2015 18:22 |
URI: | http://eprints.esc.cam.ac.uk/id/eprint/3233 |
Actions (login required)
![]() |
View Item |