Glacial discharge into the subarctic Northeast Pacific Ocean during the last glacial

摘要

Understanding the response of the climate to abrupt changes in the Earth system represents a key objective in paleoclimatol-ogy. Heinrich events in the last glacial, during which significant amounts of glacial discharge entered the North Atlantic Ocean, triggered the development of colder conditions across much of the globe. Despite widespread documentation of these events, including their occurrence and global significance, the impact of Heinrich events on the North American Cordilleran Ice Sheet and subarctic North Pacific Ocean remains relatively unconstrained. Here, records of diatom oxygen isotopes are used to show that significant amounts of glacial discharge from the Cordilleran Ice Sheet were released into the open waters of the northeast Pacific Ocean throughout the last glacial. Based on the available age model, many of these episodes and calculated changes in sea surface salinity coincide with Heinrich events. If accurate, these findings would confirm that ocean-atmospheric teleconnections linked the North Atlantic and North Pacific Oceans during intervals of abrupt change in the last glacial, as well as indicating the wider susceptibility of regional ice-sheets to global alterations in the climate system.