Direct comparison of marine and terrestrial climate variability during marine isotope stages 6 and 5: Results from Santa Barbara Basin ODP Hole 893A

Planktonic foraminiferal δ18O, pollen, and opal records from Santa Barbara Basin are used to evaluate climate changes in the northeast Pacific during marine isotope stages (MIS) 6 and 5. While the oak and foraminifera record the major glacial‐interglacial changes, opal is not correlated with these large‐scale transitions. Surface water warming in the basin was synchronous with terrestrial warming but earlier than ice sheet melting and increasing Northern Hemisphere insolation at Termination II. During and immediately after deglaciation, our marine proxies indicate the presence of an isothermal upper water column. Later in substage 5E, the water column became thermally stratified, surface productivity increased, and laminated sediments began accumulating. Sediment trap and hydrographic data suggest these changes were due to the onset of a strong seasonal cycle similar to that seen today in the basin. A series of rapid coolings within MIS 5 appears to be synchronous with North Atlantic ice‐rafting events and Greenland stadials.