DEVELOPPEMENT PAUVRETE ET INSTITUTIONS Introduction au thème Marc Gurgand et Akiko Suwa-Eisenmann
The age reconstruction of the bottom part of the Siple Dome Ice Core Makoto Suwa 1*, Jinho Ahn 2,...
18
The age reconstruction The age reconstruction of the bottom part of of the bottom part of the Siple Dome Ice Core the Siple Dome Ice Core Makoto Suwa Makoto Suwa 1* 1* , Jinho Ahn , Jinho Ahn 2 , Bruce Barnett , Bruce Barnett 1 , , Michael Bender Michael Bender 1 , Ed Brook , Ed Brook 3 , Martin Wahlen , Martin Wahlen 2 and James White and James White 4 1 Department of Geosciences, Princeton University, Princeton, NJ, Department of Geosciences, Princeton University, Princeton, NJ, USA USA 2 Scripps Institution of Oceanography, University of California Scripps Institution of Oceanography, University of California San Diego, CA, USA San Diego, CA, USA 3 Department of Geology and Program in Environmental Science, Department of Geology and Program in Environmental Science, Washington State University, Vancouver, WA, USA Washington State University, Vancouver, WA, USA 4 Institute for Arctic and Alpine Research, and Department of Institute for Arctic and Alpine Research, and Department of Geological Sciences, University of Colorado, Boulder, CO, USA. Geological Sciences, University of Colorado, Boulder, CO, USA. *To whom correspondence should be addressed: [email protected] *To whom correspondence should be addressed: [email protected]
-
Upload
brenda-cobb -
Category
Documents
-
view
213 -
download
0
Transcript of The age reconstruction of the bottom part of the Siple Dome Ice Core Makoto Suwa 1*, Jinho Ahn 2,...
The age reconstruction of the The age reconstruction of the bottom part of the Siple bottom part of the Siple
Dome Ice CoreDome Ice CoreMakoto SuwaMakoto Suwa1*1*, Jinho Ahn, Jinho Ahn22, Bruce Barnett, Bruce Barnett11, Michael , Michael BenderBender11, Ed Brook, Ed Brook33, Martin Wahlen, Martin Wahlen22 and James and James WhiteWhite44
11Department of Geosciences, Princeton University, Princeton, NJ, USADepartment of Geosciences, Princeton University, Princeton, NJ, USA22Scripps Institution of Oceanography, University of California San Diego, CA, Scripps Institution of Oceanography, University of California San Diego, CA, USAUSA33Department of Geology and Program in Environmental Science, Washington Department of Geology and Program in Environmental Science, Washington State University, Vancouver, WA, USAState University, Vancouver, WA, USA44Institute for Arctic and Alpine Research, and Department of Geological Institute for Arctic and Alpine Research, and Department of Geological Sciences, University of Colorado, Boulder, CO, USA. Sciences, University of Colorado, Boulder, CO, USA.
*To whom correspondence should be addressed: [email protected]*To whom correspondence should be addressed: [email protected]
Vostok Ice Core
Siple Dome Ice Core
97.6 Ka
Extrapolated time scale > 97.6 ka
temperature proxy
δ18O of atmospheric O2
CH4
CO2
Bottom section of the Siple Dome Ice Core
CH4 cut off = 800ppbv
CO2 cut off = 300ppmv
~3-4%
δD
δ18O of atmospheric O2
CH4
CO2
total gas content
~40%δ15N of atmospheric N2
Method 1Method 1
97.6 ka
150
130
149148147146145
144143
142141
140139138
137
136
135134 133
132
128
131
129
126127
125 124
123122
121120
101 102103
104
105
106
107108
109 110111 112113114
115
116
118117
119
•Use δ18O – CO2 to constrain age for the bottom part of the Siple Dome Ice Core.•Use CH4 to validate the age reconstruction
Vostok δ18O – CO2
100 ka
150
130
149148147146145
144143
142141
140139138
137
136
135134 133
132
128
131
129
126127
125 124
123122
121120
101 102103
104
105
106
107108
109 110111 112113114
115
116
118117
119
Method 1Method 1
Vostok δ18O – CO2
Method 2Method 2
•Use CH4 – δ18O – CO2 to constrain age for the bottom part of the Siple Dome Ice Core.
Vostok CH4 – δ18O – CO2
150 ka97.6 ka
Method 1 Method 1 (δ18O – CO2 to constrain age)
δD
δ18O of atmospheric O2
CH4
CO2
Method 2 Method 2 (CH4 – δ18O – CO2 to constrain age)
δD
δ18O of atmospheric O2
CH4
CO2
Method 1 Method 1 (δ18O – CO2 to constrain age)
106.5 ka
980.1 m - 982.6 m
Method 2 Method 2 (CH4 – δ18O – CO2 to constrain age)
106.5 ka
980.1 m - 982.6 m
ConclusionsConclusions
• Most of the bottom ice (below 976 m) is from 100 Most of the bottom ice (below 976 m) is from 100 ka – 135 ka ka – 135 ka
• Our results suggest that disturbance of the ice Our results suggest that disturbance of the ice starts between 980.1 m and 982.6 m below starts between 980.1 m and 982.6 m below surface, i.e. stratigraphy is undisturbed up to 106.5 surface, i.e. stratigraphy is undisturbed up to 106.5 ka ka
• We do not find ice from the warmest period of the We do not find ice from the warmest period of the last interglacial, MIS–5e.last interglacial, MIS–5e.
• The bottom-most 5m of ice has anomaly low The bottom-most 5m of ice has anomaly low δδD D record.record. Could have been formed at a higher Could have been formed at a higher elevation site and flowed into the Siple Dome area. elevation site and flowed into the Siple Dome area. The total gas content of this ice is 3-4% lower, and The total gas content of this ice is 3-4% lower, and δδ1515NN is ~40% higher than for samples right above is ~40% higher than for samples right above this section. this section.
97 ka ~ 300 ka
Method 1 Method 1 (δ18O – CO2 to constrain age)
δD
δ18O of atmospheric O2
CH4
CO2
Method 2 Method 2 (CH4 – δ18O – CO2 to constrain age)
δD
δ18O of atmospheric O2
CH4
CO2
Method 1 Method 1 (δ18O – CO2 to constrain age)
106.5 ka
980.1 m - 982.6 m
Method 1 Method 1 (δ18O – CO2 to constrain age)
δD
δ18O of atmospheric O2
CH4
CO2
Method 1 Method 1 (δ18O – CO2 to constrain age)
![Suwa Kanako Resume€¦ · Kanako Suwa [Bilingual Education, ESL PreK-6] phone: 857-333-7199 email: kana7121@bu.edu Skype: kanakosuwa Twitter: @KanakoSuwa DOB : January 21st, 1995](https://static.fdocuments.in/doc/165x107/6009abfdecc33309b60c423d/suwa-kanako-resume-kanako-suwa-bilingual-education-esl-prek-6-phone-857-333-7199.jpg)
