Evidence for orbitally controlled size variations of the East Antarctic Ice Sheet during the late Miocene

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

10

Scientific paper

Ocean Drilling Program Site 1165 penetrated drift sediments on the East Antarctic continental rise and recovered sediments from a low-energy depositional environment. The sediments are characterized by prominent alternations between a green to greenish-gray diatom-bearing hemipelagic facies and gray to dark gray hemiturbiditic facies. Our investigation of an upper Miocene section, using high-resolution color spectra, multisensor core logs, and X-ray fluorescence scans, reveals that sedimentation changes occur at Milankovitch orbital frequencies of obliquity and precession. We use this finding to derive an astronomical calibrated time scale and to calculate iron mass-accumulation rates, as a proxy for sediment-accumulation rates. Terrigenous iron fluxes change by as much as 100% during each obliquity cycle. This change and an episodic pattern of enhanced ice-rafted debris deposition during times of deglaciation provide evidence for a dynamic and likely wet-based late Miocene East Antarctic Ice Sheet (EAIS) that underwent large size variations at orbital time scales. The dynamic behavior of the EAIS implies that a significant proportion of the variability seen in oxygen isotope records of the late Miocene reflects Antarctic ice-volume changes.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Evidence for orbitally controlled size variations of the East Antarctic Ice Sheet during the late Miocene does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Evidence for orbitally controlled size variations of the East Antarctic Ice Sheet during the late Miocene, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for orbitally controlled size variations of the East Antarctic Ice Sheet during the late Miocene will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1482329

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.