Ocean temperature impact on ice shelf and glaciers around the Antarctic Peninsula during the Holocene

Abstract

The Antarctic Peninsula is one of the most affected regions on Earth by the global warming. Both surface atmosphere and subsurface ocean temperatures have rapidly increased over the last decades and contributed to massive regional ice shelf and glacier regressions. However, we still need to further understand the relationship between changes in temperatures and ice cap, especially around the North of the Peninsula where the glaciers have the potential to raise sea level by nearly 70m. To this aim, we provide a new subsurface ocean temperature (SOT) (50-400m) record in the northern Antarctic Peninsula spanning the last 9,000 years before present (BP). We applied the TEX86L (TetraEther Index of tetraethers with 86 carbons) proxy for low temperatures to the relatively well-dated marine core Jumbo Piston Core (JPC) 33, retrieved in the southern Bransfield Strait. Our new Holocene SOT record reveals a strong +3ºC warming episode between 8.3 and 6.5 kyrs BP, before a cooling period preceding a second +2ºC warming phase during the last 4.0 kyrs BP. These two warming intervals are synchronous with pronounced regional ice shelf and glaciers retreat. Similar connections between increasing SOT and ice cap recession have also been reported along the Western and Eastern Antarctic Peninsula, thus confirming the predominant role of the SOT, mainly tied to the enhanced supply of relatively warm subsurface deep waters onto the ice shelf, on the ice cap extent over the last millennia.