Sea-surface temperature anomalies associated with the 1997-1998 El Nino recorded in the oxygen isotope composition of planktonic foraminifera

Anomalously warm sea-surface temperatures and associated high rainfall prop agated northward from the eastern equatorial Pacific along the western marg in of North America during the 1997-98 El Nino. We present data from the Gu aymas Basin (Gulf of California) and the Santa Barbara Basin (Southern Cali fornia Borderlands) that clearly demonstrate that the oxygen isotope compos ition of planktonic foraminifera accurately records the local sea-surface t emperature changes related to the El Nino phenomenon. On the basis of this observation, the varved sediments accumulating in these basins should conta in a detailed history of both the occurrence and intensity of past El Nino events.