Future plans and strategy of IODP drilling in Antarctica and the Southern Ocean

• Main Author: Gohl, Karsten
• Format: Conference Object
• Language: unknown
• Published: 2015
• Subjects: Antarc*; Antarctic; Antarctica; Greenland; Ice Sheet; Southern Ocean
• Online Access: https://epic.awi.de/id/eprint/37939/; https://hdl.handle.net/10013/epic.45502

The International Ocean Discovery Program (IODP) states in its current IODP Science Plan for 2013-2023 that the polar regions are one of the primary target areas for scientific drilling using the drill vessels Joides Resolution and Chikyu as well as various drilling options in so-called Mission-Specific Platforms. In particular this is expressed in the Science Plan’s Key Theme “Climate and Ocean Change” and its Challenge 1 “How does Earth’s climate system respond to elevated levels of atmospheric CO2” and Challenge 2 “How do ice sheets and sea level respond to a warming climate”: The response of ice sheets to a warmer climate can be reconstructed from sedimentary records of relatively recent interglacial episodes when ice extent was similar, or slightly less than at present, and from much earlier times (34 - 3 Ma) when climate was several degrees warmer than today. Analysis of recently recovered ocean sediment cores suggests that the West Antarctic Ice Sheet (WAIS), with a potential of 4 m sea level rise, is particularly sensitive to climate change and may have collapsed many times over the last 5 million years. Estimates of sea level rise during warm intervals about 3 million years ago suggest the possibility of even larger changes. The Greenland Ice Sheet and WAIS together account for only about 12 m of potential sea level, so estimates greater than 12 m imply a significant loss of ice from the much larger East Antarctic Ice Sheet, containing the equivalent of about 52 m of sea level. Some of the major questions to be urgently addressed are: Did large sections of the West and East Antarctic Ice Sheets collapse the last time when atmospheric CO2 levels reached 400 ppm? What are the time spans over which past ice sheet collapses occurred, and how much warming was required to push them past their “tipping points”? To answer these questions, sediment cores are needed from the Antarctic shelves and slopes where sediment accumulates rapidly. This information is needed, along with land-based records, to constrain ...