Davide Oppo, School of Geosciences University of Louisiana at Lafayette
Individual benthic foraminifera analysis and its use in reconstructing the history of methane seeps
Abstract:
Ongoing research seeks to identify locations and timing of hydrate dissociation activity, with the ultimate goal of better understanding mechanisms of hydrate instability and feedback related to climate change. Methane hydrates in ocean sediments have been investigated across various timescales using various indicators to better understand hydrate dynamics. The dissociation of methane hydrate drives increased pore water alkalinity and dissolved inorganic carbon, in which the carbon carries the strongly negative isotopic values of the methane from which it is derived. This negative isotopic signal can be incorporated into the CaCO3 skeletal material of foraminifera.
Negative foraminifera δ13C anomalies have been used to indicate methane hydrate dissociation. However, bulk isotopic analysis limits the temporal resolution to reconstruct past dissociation events. We present new benthic and planktonic δ13C and δ18O Individual Foraminifera Analyses of multiple benthic and planktonic species, documenting the unique response to methane seepage of three benthic genera within the Miliolida order. From these results, we infer species within these three Miliolida genera are sensitive recorders of short-duration, transient hydrate dissociation events; events insufficient to precipitate authigenic carbonate crusts and develop macro-biological communities at the seafloor.
Dial-In Information
https://oregonstate.zoom.us/j/92715005615?pwd=RnM2SmdjZXZud3RrV2J1VTZMZlRKdz09
Meeting ID: 927 1500 5615
Password: 152832
Wednesday, April 19, 2023 at 2:30pm to 3:30pm
Virtual EventFree and open to the public
Ernest Colantonio
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