Posted ContentMajor West Antarctic Ice Sheet retreat events during the Pliocene: Evidence from the sediment provenance analyses of Amundsen Sea IODP U1532 recordsHorikawa, Keiji (ORCID:0000000303370413); Iwai, Masao (ORCID:0000000174891262); Hillenbrand, Claus-Dieter; Siddoway, Christine S (ORCID:0000000304786138); Halberstadt, Anna Ruth (ORCID:0000000325827074); Cowan, Ellen A (ORCID:0000000165125769); Penkrot, Michelle L; Gohl, Karsten (ORCID:0000000295582116); Wellner, Julia S (ORCID:0000000268078635); Asahara, Yoshihiro; Shin, Ki-Cheol<p>The stability of the West Antarctic Ice Sheet (WAIS), crucial for preventing major future sea-level rise, is threatened by ocean-forced melting in the Pacific sector, especially in the Amundsen Sea. So far, direct evidence of the extent and rate of WAIS retreat during past warm periods has been lacking. Here, we analyzed detrital Nd, Sr, and Pb isotope data of sediments ( 18.93 for 206Pb/204Pb) and low eNd (< &#8211;5 eNd) values. This distinct isotopic signature suggests long-distance supply of detritus sourced from plutonic rocks located in the continental interior. The presence of this material at Site U1532 indicates major inland retreat of the WAIS during the immediately preceding interglacials, which allowed icebergs to transport and deposit the detritus on the Amundsen Sea shelf. Our Pliocene records reveal multiple major inland retreats of the WAIS, highlighting the extent of possible WAIS response to ongoing global warming.&#160;</p>European Geophysical Union2025-04-2710654899https://doi.org/10.5194/egusphere-egu25-145121917176National Science Foundation