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Multidecadal to centennial planktic δ18O and Mg/Ca records were generated at Ocean Drilling Program Site 976 (ODP976) in the Alboran Sea. The site is in the flow path of Atlantic inflow waters entering the Mediterranean and captured North Atlantic signals through the surface inflow and the atmosphere. The records reveal similar climatic oscillations during the last two glacial‐to‐interglacial transitions, albeit with a different temporal pacing. Glacial termination 1 (T1) was marked by Heinrich event 1 (H1), post‐H1 Bølling/Allerød warming, and Younger Dryas (YD) cooling. During T2 the H11 δ18O anomaly was twice as high and lasted 30% longer than during H1. The post‐H11 warming marked the start of MIS5e while the subsequent YD‐style cooling occurred during early MIS5e. The post‐H11 temperature increase at ODP976 matched the sudden Asian Monsoon Termination II at 129 ka B.P. Extending the 230Th‐dated speleothem timescale to ODP976 suggests glacial conditions in the Northeast Atlantic region were terminated abruptly and interglacial warmth was reached in less than a millennium. The early‐MIS5e cooling and freshening at ODP976 coincided with similar changes at North Atlantic sites suggesting this was a basin‐wide event. By analogy with T1, we argue that this was a YD‐type event that was shifted into the early stages of the last interglacial period. This scenario is consistent with evidence from northern North Atlantic and Nordic Sea sites that the continuing disintegration of the large Saalian Stage (MIS6) ice sheet in Eurasia delayed the advection of warm North Atlantic waters and full‐strength convective overturn until later stages of MIS5e. Last Interglacial started within 1000 years or lessYounger Dryas‐type rebound occurred during last interglacialContinuing ice melt delayed full interglacial conditions by several millennia

The rise in atmospheric CO2concentrations observed at the end of glacial periods has, at least in part, been attributed to the upwelling of carbon-rich deep water in the Southern Ocean. The magnitude of outgassing of dissolved CO2, however, is influenced by the biological fixation of upwelled inorganic carbon and its transfer back to the deep sea as organic carbon. The efficiency of this biological pump is controlled by the extent of nutrient utilization, which can be stimulated by the delivery of iron by atmospheric dust particles. Changes in nutrient utilization should be reflected in the d13C gradient between intermediate and deep waters. Here we use the d13C values of intermediate- and bottom-dwelling foraminifera to reconstruct the carbon isotope gradient between thermocline and abyssal water in the subantarctic zone of the South Atlantic Ocean over the past 360,000 years. We find millennial-scale oscillations of the carbon isotope gradient that correspond to changes in dust flux and atmospheric CO2concentrations as reported from Antarctic ice cores. We interpret this correlation as a relationship between the efficiency of the biological pump and fertilization by dust-borne iron. As the correlation is exponential, we suggest that the sensitivity of the biological pump to dust-borne iron fertilization may be increased when the background dust flux is low.

James F. Lander and Patricia A. Lockridge, United States Tsunamis (including United States possessions) 1690-1988. Publication 41-2, NOAA, August 1989, 265 p.Nannofossils and Their Application. Jason A. Crux and Shirley E. van Heck, eds. Proceedings of the International Nannofossil Association Conference, London 1987. British Micropalaeontological Society Series (New York: Halsted Press, John Wiley & Sons, 1989), 356 pp.Andrew Brookes, Channelized Rivers: Perspectives for Environmental Management. (New York: John Wiley & Sons, 1988), 326 pp. $79.95.Roger N. Anderson, Marine Geology: A Planet Earth Perspective. Revised edition. (New York: John Wiley & Sons, 1989), 328 pp. $39.95.

A core 120 km off the coast of southern Oregon was examined for changes in lithology, diatoms, and pollen over the past 30,000 yr. Primary production during the late Pleistocene was about half that of the Holocene. Evidence from diatoms and pollen indicates that summer upwelling was much weaker, implying an absence of strong northerly winds. Early Pliocene diatoms found throughout the late Pleistocene section were probably derived from diatomites east of the Cascades and provide evidence for strong easterly winds over a dry continental interior. The findings verify predictions of a climate model based on glacial maximum conditions. There is no compelling evidence for a climatic reversal corresponding to the European Younger Dryas chron. During the early Holocene (9000−7000 yr B.P.) there may have been years when winds were insufficiently strong to support upwelling, so that warm stratified waters lay closer to the coast.

There has been much speculation about the history of the Arctic Ocean, particularly its response to the late Quaternary climatic fluctuations1–8. As a result, considerable data have been gathered from Arctic Ocean sediment cores to reconstruct glacial and interglacial Arctic Ocean palaeoenvironments8,9. But even with these data the reconstructions and the correlations with the Quaternary chronostratigraphy have been unsatisfactory, mainly because of the lack of detailed stratigraphical data such as those provided by stable oxygen-isotope stratigraphy10. Here we present stable isotope records from Arctic Ocean sediment cores which can be correlated convincingly with corresponding data from the North Atlantic. Together with lithostratigraphical data, they provide new evidence on Arctic Ocean history in relation to global late Quaternary climatic fluctuations.