Light δ13C events during deglaciation of the East Greenland Continental Shelf attributed to methane release from gas hydrates

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Abstract

We have documented high-resolution stable isotope records from three marine cores on the East Greenland shelf. These records exhibit three rapid light δ13C events (−3 to −7‰) in benthic and planktic foraminifera during deglaciation that are spatially and temporally transgressive. The light δ13C events are associated with light planktic δ18O, indicative of meltwater. In Kangerlussuaq Trough, the first δ13C event occurs at initial deglaciation, 13.94–14.0 cal ka and the second occurs at 12.85–12.9 cal ka. A younger event at 10.3–9.3 cal ka is recorded near the mouth of Nansen Fjord during final deglaciation. The hypothesized mechanism for the light δ13C is expulsion of methane from gas hydrates in the seafloor from pressure release during ice sheet retreat.

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