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What Will Core Drilling in the Most Powerful Ocean Current Reveal? Adapted from Information by Columbia University and the International Ocean Discovery Program A team of 30 scientists from 13 countries sailed from Puntas Arenas, Chile, on the ship JOIDES Resolution , to begin Expedition 383 of the International Ocean Discovery Program (IODP) last spring. The team plans to drill into the seabed of some of the planet’s most remote marine regions to study the Antarctic Circumpolar Current (ACC) and how it might respond to human-induced climate change. The ACC is the world’s largest current system and the only current which flows all the way around the globe without getting diverted by landmass. It sends up to 150 times the flow of all the world’s rivers clockwise around Antarctica connecting all three major ocean basins, the Pacific, Atlantic, and Indian. “This is really a key piece of the world climate system, because this is where so much heat and carbon are exchanged between the ocean and the atmosphere,” said cochief scientist Gisela Winckler, a geochemist and paleoclimatologist at Columbia University’s Lamont-Doherty Earth Observatory. “We should learn about how the winds, the ocean, and the Antarctic ice sheet have responded to warming in the past. That will help us know what they might do in the future.” Little is known about how the ACC works, but it is believed to play a key role in regulating natural climate swings. What is known is that the ACC is a complex set of currents with spinoffs containing huge amounts of carbon dioxide, nutri- ents, and heat from the deep ocean. Scientists plan to drill into sediment lying 3300-16,500 feet beneath the sea surface, and gather cores up to 1600 feet long. The first cores will come from the continental shelf along the southernmost coast of Chile where the ACC must pass through the narrow Drake Passage between South America and the Antarctic peninsula. The deeper cores will come from the southeastern Pacific, near the oceanic pole of inaccessibility, also known as Point Nemo. This spot in the ocean is the farthest from any land - more than 1000 miles in any direction. In fact, at certain times, this location is closer to the International Space Station than to inhabited land. The shallow cores are expected to contain shells of tiny creatures that died and sank to the bottom of the ocean some 8 million years ago. These capture information about ancient water temperatures, plankton production, nutrient concentrations, and other qualities which could help map the changes in the ACC’s strength and other workings. Cores from the southeast Pacific may contain rocky debris scraped up by glaciers in Antarctica, rafted out to sea in icebergs, and then dropped to the bottom when the bergs melted. Changes in this debris over time would allow researchers to see how the ice sheet reacted to cold and hot swings hooked into the ACC. One mystery the scientists are hop- ing to solve is how the ACC has not become any stronger even though the powerful winds from the west that drive the ACC’s clockwise motion have increased in recent decades. Coring may help scientists test hypotheses about why. 23 WorldWide Drilling Resource ® JANUARY 2020 Dealmakers Daniel Mosley, Jr. of MG Services in Dilley, Texas, stands proudly by his new 9X3 pump hoist from TDH Manufacturing in Haslet, Texas. TDH Manufacturing Send your deals to: michele@ worldwidedrillingresource.com ENV