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Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum

March 16, 2022
The Paleocene-Eocene Thermal Maximum (PETM) is recognized by a major negative carbon isotope (δ13C) excursion (CIE) signifying an injection of isotopically light carbon into exogenic reservoirs, the mass, source, and tempo of which continue to be debated. Evidence of a transient precursor carbon release(s) has been identified in a few localities, although it remains equivocal whether there is a global signal. Here, we present foraminiferal δ13C records from a marine continental margin section, which reveal a 1.0 to 1.5‰ negative pre-onset excursion (POE), and concomitant rise in sea surface temperature of at least 2°C and a decline in ocean pH. The recovery of both δ13C and pH before the CIE onset and apparent absence of a POE in deep-sea records suggests a rapid (< ocean mixing time scales) carbon release, followed by recovery driven by deep-sea mixing. Carbon released during the POE is therefore likely more similar to ongoing anthropogenic emissions in mass and rate than the main CIE.

Citation Information

Publication Year 2022
Title Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum
DOI 10.1126/sciadv.abg1025
Authors Tali L. Babila, Don E Penman, CD Standish, Monica Doubrawa, Tim J Bralower, Marci M. Robinson, Jean Self-Trail, Robert P Speijer, Peter Stassen, Gavin L Foster, James C. Zachos
Publication Type Article
Publication Subtype Journal Article
Series Title Science Advances
Index ID 70230533
Record Source USGS Publications Warehouse
USGS Organization Florence Bascom Geoscience Center