Pacific Highs: A Treasure Trove of Past Warm Climate Archives

Abstract

Past ocean conditions are recorded in deep-sea sediments, which provide opportunities to ground truth future climate change scenarios and their impacts on marine ecosystems—fundamental and urgent societal challenges. The Pacific Ocean is the largest and deepest ocean basin on Earth and currently holds more carbon and heat than any other ocean. Much of what we know about past conditions in the Pacific during warm climates, including times of widespread oceanic anoxia and large-scale ecosystem turnover, is from sediment cores drilled at a handful of locations. Climate models stress the importance of the Pacific Ocean for global climate, carbon storage, ocean heat content and ocean circulation, but existing regional proxy records are insufficient to test these models. We highlight findings from a workshop centered on building consortia around shared research questions whose answers lie within ancient Pacific sediments. Coordinated international efforts are needed to (a) systematically revisit legacy deep-sea sediment records, (b) plan expeditions to recover well-preserved sediments from intervals of major scientific interest, and (c) explore new locations with the aim to study geological analogs of future conditions, and thus transform our understanding of Earth's life and climate systems. We argue that Pacific Highs (e.g., Shatsky Rise, Hess Rise, Mid-Pacific Mountains, Magellan Rise) have the potential to deliver new high-resolution carbonate-rich sediments for paleoceanographic reconstructions. In addition to scientific discoveries, these efforts will provide opportunities to engage and train a new generation of scientific ocean drilling scientists.