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Volcanic Ash Record in the Siple Dome Ice Core N.W. Dunbar 1, A. Kurbatov 2, G.A. Zielinski 2, W.C. McIntosh 1, P.B. Price 3, R.C. Bay 3 1. E&ES Department,

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Presentation on theme: "Volcanic Ash Record in the Siple Dome Ice Core N.W. Dunbar 1, A. Kurbatov 2, G.A. Zielinski 2, W.C. McIntosh 1, P.B. Price 3, R.C. Bay 3 1. E&ES Department,"— Presentation transcript:

1 Volcanic Ash Record in the Siple Dome Ice Core N.W. Dunbar 1, A. Kurbatov 2, G.A. Zielinski 2, W.C. McIntosh 1, P.B. Price 3, R.C. Bay 3 1. E&ES Department, New Mexico Tech, Socorro, NM, Climate Change Institute, University of Maine, Orono, ME Physics Department, University of California, Berkeley, CA 94720

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5 Techniques for finding tephra layers in ice cores Visual identification Sulfate record Searching at depth of known eruptions Optical dust logger

6 Tephra layers found in Siple Dome A ice core A total of 40 layers with adequate ash for chemical analysis have been found.

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9 Analysis of tephra layers in the Siple Dome core indicates derivation from: Mt. Berlin (most layers) Mt. Takahe Pleiades Volcanic Center/Mt. Melbourne local basaltic centers in the Royal Society Range at least one non-Antarctic volcano

10 Microbeam chemical analysis of glass shards in tephra layers coupled with statistical difference calculations allows: 1. Correlation to tephra layers in other ice cores 2. Correlation to eruptions of known age to provide time- stratigraphic markers

11 79.2 m 1147 yrs bef. 1995?? Prefer 675+/-25 yrs before m 703 yrs before 1995 Cross-correlation between ice cores

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13 Mt. Takahe 8.2+/-2.7 Mt. Berlin 10.3+/-2.7 Mt. Hudson 11.1+/-1.8

14 TIf Mt. Hudson 11.1+/-1.8 Mt. Berlin 10.3+/-2.7 Mt. Takahe 8.2+/-2.7

15 Mt. Berlin 24.7+/-1.5 Mt. Berlin <92.2+/-0.9 Mt. Berlin <118.7+/-2.5?? Mt. Berlin 18.2+/-5.8

16 Conclusions There are many identifiable and analyzable tephra layers in the Siple Dome Ice Core, and probably will be in other WAIS cores Most tephra layers are locally-derived, most having been erupted from Mt. Berlin, located in West Antarctica, although Mt. Takahe, the Pleiades volcano and some basaltic centers are also represented. Several non-local tephra (probably South American) have also been identified Cross correlation of tephra layers between ice cores allow for better- dated cores to aid in dating of other cores. This also provide absolute time-stratigraphic markers between cores Chronology of tephra layers in the upper part of the Siple Dome core agree well with existing chronology, however agreement in the lower part of the core is less good. Further dating of source ashes (Mt. Berlin) may provide further information about age of lower Siple Dome tephra layers


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