A smoking gun for methane hydrate release during the Paleocene-Eocene thermal maximum

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Author(s): Frieling, Joost; Peterse, Francien; Lunt, Dan John; Bohaty, Steven M.; Sinninghe Damsté, Jaap S.; Reichart, Gert-Jan; Sluijs, Appy
Author Affiliation(s): Primary:
Utrecht University, Utrecht, Netherlands
University of Bristol, United Kingdom
University of Southampton, United Kingdom
Royal Netherlands Institute for Sea Research, Netherlands
Volume Title: AGU 2016 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2016; American Geophysical Union 2016 fall meeting, San Francisco, CA, Dec. 12-16, 2016. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The Paleocene-Eocene Thermal Maximum (PETM; ∼56 Ma) was a period of rapid 4-5°C global warming and a global negative carbon isotope excursion (CIE) of 3-4.5 ppm, signaling the input of at least 1500 Gt of δ13C-depleted carbon into the ocean-atmosphere system. Methane from submarine hydrates has long been proposed as a carbon source, but direct and indirect evidence is lacking. We generated a new high-resolution TEX86 and δ13C record from Ocean Drilling Program Site 959 in the eastern tropical Atlantic and find that initial warming preceded the PETM CIE by ∼10 kyr. Moreover, time-shifted cross-correlations on these new and published temperature-δ13C data imply that substantial (2-3°C) warming lead 13C-depleted carbon injection by an average of 2-3 kyr globally. Finally, a data compilation shows that global burial fluxes of biogenic Ba approximately doubled across all depths of the ocean studied, which on PETM time scales can only be explained by significant Ba addition to the oceans. Submarine hydrates are Ba-rich and require warming to dissociate. The simplest explanation for the temperature lead and Ba addition to the ocean is that methane hydrate dissociated as a response to initial warming and acted as a positive carbon cycle feedback during the PETM.
Year of Publication: 2016
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Aliphatic hydrocarbons; Alkanes; Atlantic Ocean; Cenozoic; Equatorial Atlantic; Gas hydrates; Hydrocarbons; Leg 159; Methane; North Atlantic; ODP Site 959; Ocean Drilling Program; Organic compounds; Paleocene-Eocene Thermal Maximum; Paleoclimatology; Paleogene; Tertiary
Coordinates: N033740 N033740 W0024408 W0024408
Record ID: 2017051598
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