ODP Site 882 M
ag ne tic s us cp et ib ili ty mbsf M G North Pacific sediment character Ocean drilling in the subarctic Pacific during ODP Leg 145 recovered high-resolution records of the onset of Northern Hemisphere glaciation. Cores from Detroit Seamount in the northern Emperor Seamount chain and from Patton-Mur...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.621.8759 http://odplegacy.org/PDF/Outreach/Brochures/Greatest_Hits/Events/Rea.pdf |
| Summary: | ag ne tic s us cp et ib ili ty mbsf M G North Pacific sediment character Ocean drilling in the subarctic Pacific during ODP Leg 145 recovered high-resolution records of the onset of Northern Hemisphere glaciation. Cores from Detroit Seamount in the northern Emperor Seamount chain and from Patton-Murray Seamount in the Gulf of Alaska show the transition from nearly pure siliceous oozes that characterize preglacial times to ash-, clay-, and ice rafted debris-rich ooze of the glacial ages was very sudden, a matter of at most one or two thousand years [Rea et al., 1995]. The transition occurs everywhere at 2.65 Ma and records a sudden change in continental weathering and erosion all around the North Pacific basin. Since the rate of change is an indication of cause, both tectonic forcing, which requires many hundreds of thousands of years, and orbital forcing, which requires ten or more thousand years, seem to be ruled out as direct causes of the 2.65 Ma onset of Northern Hemisphere glaciation. Therefore we have turned our attention to the period of intense volcanic activity that began all around the North Pacific at exactly this same time. The Sudden onset of Northern Hemisphere glaciation at 2.65 Ma: A possible result of volcanic forcing |
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