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| Titel |
Continuous and discrete measurements of atmospheric methane from an ice core from Roosevelt Island, East Ross Sea, Antarctica |
| VerfasserIn |
James Lee, Ed Brook, Thomas Blunier, Paul Vallelonga, Nancy Bertler |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250093899
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| Publikation (Nr.) |
 EGU/EGU2014-9078.pdf |
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| Zusammenfassung |
| A new ice core from Roosevelt Island was drilled for the Roosevelt Island Climate Evolution
(RICE) project to establish the history of deglaciation of the Ross Sea through the Holocene.
Evidence of glacial retreat in the Ross Sea Embayment shows that deglaciation happened in
several stages of rapid collapse and persisted well after the melting of the Northern
Hemisphere ice sheets was complete. The ice rise on Roosevelt Island records the timing of
the last leap when the West Antarctic Ice Sheet (WAIS) receded past Roosevelt
Island.
In order to discern the timing of deglaciation, a precise age-depth relationship is required
for the RICE ice core. We present a timescale for Roosevelt Island using mixing ratios of
methane in air preserved within the ice core measured continuously with a Picarro laser
spectrometer as well as in high-resolution with gas chromatography (GC). Discrete data from
GC analysis over the top 400m of core replicate both the magnitude and variations from
other high-resolution ice core records from WAIS Divide, Law Dome, GISP2 and
NEEM S1. Both the continuous and discrete methane records of the RICE core
were matched to these established records and provide an accurate and consistent
depth-age relationship for the past 3.6kyr. Future work on the 400-750m depth section is
expected to extend the RICE chronology to at least the Last Glacial Maximum. |
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