Rj. Behl et Jp. Kennett, BRIEF INTERSTADIAL EVENTS IN THE SANTA-BARBARA BASIN, NE PACIFIC, DURING THE PAST 60 KYR, Nature, 379(6562), 1996, pp. 243-246
THE instability of the Northern Hemisphere glacial climate over the pa
st 100 kyr has been revealed by at least 20 brief warm (interstadial)
episodes, called Dansgaard-Oeschger events, recorded in Greenland ice
cores(1-3) and in North Atlantic sedimentary records(4,5). A few of th
ese events have been recognized elsewhere(6-8). Here we describe a rec
ord of ocean oxygenation and circulation from the Santa Barbara basin
in the northeast Pacific Ocean which correlates well,vith the Greenlan
d ice-core records. We see 19 of the 20 Dansgaard-Oeschger events, in
the form of laminated sediments deposited under anoxic conditions, and
we can correlate at least 16 of these with the 17 ice-core interstadi
als of the past 60 kyr. Thus, these short-term events were not restric
ted to the North Atlantic region. The events had substantial ecologica
l and oceanographic effects in the Santa Barbara basin, including chan
ges in benthic faunal populations and in the age and composition of bo
ttom waters. Similar ventilation changes have been seen in the Gulf of
California(9,10), suggesting that these changes may have been widespr
ead and synchronous along the northeast Pacific margin. These results
suggest sensitivity of broad areas of the ocean-atmosphere-cryosphere
system to short-term climate change.