Obliquity Pacing of the Late Pleistocene Glacial Terminations
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منابع مشابه
Glacial variability over the last two million years: an extended depth-derived agemodel, continuous obliquity pacing, and the Pleistocene progression
An agemodel not relying upon orbital assumptions is estimated over the last 2Ma using depth in marine sediment cores as a proxy for time. Agemodel uncertainty averages 10Ka in the early Pleistocene ( 2–1Ma) and 7Ka in the late Pleistocene ( 1Ma to the present). Twelve benthic and five planktic d O records are pinned to the agemodel and averaged together to provide a record of glacial variabilit...
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Throughout the last ∼ 900 kyr, the Late Pleistocene, Earth has experienced periods of cold glacial climate, punctuated by seven abrupt transitions to warm interglacials, the so-called terminations. Although most of glacial ice is located in the Northern Hemisphere (NH), the Southern Hemisphere (SH) seems to play a crucial role in deglaciation. Variation in the seasonal distribution of solar ins...
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Early Pleistocene glacial cycles in marine δO exhibit strong obliquity pacing, but there is a perplexing lack of precession variability despite its important influence on summer insolation intensity – the presumed forcing of ice sheet growth and decay according to the Milankovitch hypothesis. This puzzle has been explained in two ways: Northern Hemisphere ice sheets instead respond to insolatio...
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Variations in the eccentricity (100,000 yr), obliquity (41,000 yr) and precession (23,000 yr) of Earth’s orbit have been linked to glacial–interglacial climate cycles. It is generally thought that the 100,000-yr glacial cycles of the past 800,000 yr are a result of orbital eccentricity1–4. However, the eccentricity cycle produces negligible 100-kyr power in seasonal or mean annual insolation, a...
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The characteristics of glacial oscillations changed drastically 0:8Ma ago, at the ‘‘mid-Pleistocene transition’’. During the past 0.8Ma the 100kyr glacial–interglacial oscillations were strongly asymmetric (i.e., long glacial intervals of growth followed by rapid intervals of deglaciation). The 40 kyr oscillations prior to the mid-Pleistocene transition were of a smaller amplitude and lessasymm...
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