Light delta C-13 events during deglaciation of the East Greenland continental shelf attributed to methane release from gas hydrates

Citation
Lm. Smith et al., Light delta C-13 events during deglaciation of the East Greenland continental shelf attributed to methane release from gas hydrates, GEOPHYS R L, 28(11), 2001, pp. 2217-2220
Citations number
30
Categorie Soggetti
Earth Sciences
Journal title
GEOPHYSICAL RESEARCH LETTERS
ISSN journal
00948276 → ACNP
Volume
28
Issue
11
Year of publication
2001
Pages
2217 - 2220
Database
ISI
SICI code
0094-8276(20010601)28:11<2217:LDCEDD>2.0.ZU;2-K
Abstract
We have documented high-resolution stable isotope records from three marine cores on the East Greenland shelf. These records exhibit three rapid light delta C-13 events (-3 to -7 parts per thousand) in benthic and planktic fo raminifera during deglaciation that are spatially and temporally transgress ive. The light delta C-13 events are associated with light planktic delta O -18, indicative of meltwater. In Kangerlussuaq Trough, the first delta C-13 event occurs at initial deglaciation, 13.94-14.0 cal ka and the second occ urs at 12.85-12.9 cal ka. A younger event at 10.3-9.3 ed ka is recorded nea r the mouth of Nansen Fjord during final deglaciation. The hypothesized mec hanism for the light delta C-13 is expulsion of methane from gas hydrates i n the seafloor from pressure release during ice sheet retreat.