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.
|Title||Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum|
|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 Subtype||Journal Article|
|Series Title||Science Advances|
|Record Source||USGS Publications Warehouse|
|USGS Organization||Florence Bascom Geoscience Center|