Early Pleistocene East Antarctic temperature in phase with local insolation
Yan, Y.; Kurbatov, A.V.; Mayewski, P.A.; Shackleton, S.; Higgins, J.A. (2023). Early Pleistocene East Antarctic temperature in phase with local insolation. Nature Geoscience 16(1): 50-55. https://dx.doi.org/10.1038/s41561-022-01095-x
In: Nature Geoscience. Nature Publishing Group: London. ISSN 1752-0894; e-ISSN 1752-0908, more
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| Authors | | Top |
- Yan, Y.
- Kurbatov, A.V.
- Mayewski, P.A.
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- Shackleton, S.
- Higgins, J.A.
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| Abstract |
During the Pleistocene Epoch (2.58 million years ago (Ma) to 11.7 thousand years ago (ka)), intervals with extensive continental glaciation in the Americas and Eurasia (glacial) alternated with intervals in which large ice sheets were restricted to Greenland and Antarctica (interglacial). These glacial cycles are captured by the isotopic composition of oxygen (δ18O) in benthic foraminifera, a classic proxy for ice volume and seawater temperature. The δ notation here is expressed as Rsample / Rstandard − 1, where R is the ratio of interest. Before approximately 1.2 Ma, the benthic δ18O time series has a 41 thousand year (kyr) period, often interpreted to reflect insolation forcing driven by variations of Earth’s axial tilt (obliquity). After approximately 0.7 Ma, glacial cycles lengthened to an irregular, asymmetrical, but roughly approximately 100 kyr period, numerically compatible with the eccentricity variability of Earth’s orbit. The shift from the 41 kyr to the quasi-100 kyr cycle between approximately 1.2 Ma and 0.7 Ma is known as the Mid-Pleistocene Transition (MPT) |
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