| NSF Org: |
OPP Office of Polar Programs (OPP) |
| Recipient: |
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| Initial Amendment Date: | June 23, 2011 |
| Latest Amendment Date: | June 23, 2011 |
| Award Number: | 1140098 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Henrietta Edmonds
hedmonds@nsf.gov (703)292-7427 OPP Office of Polar Programs (OPP) GEO Directorate for Geosciences |
| Start Date: | July 1, 2011 |
| End Date: | June 30, 2012 (Estimated) |
| Total Intended Award Amount: | $37,759.00 |
| Total Awarded Amount to Date: | $37,759.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
7 LEBANON ST HANOVER NH US 03755-2170 (603)646-3007 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
19 Fayerweather Hanover NH US 03755-3716 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | ANS-Arctic Natural Sciences |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.078 |
ABSTRACT
The goal of this project is to investigate the long-range transport of radioactive material from the March 2011 Fukushima Daiichi nuclear reactor incident to sites in Alaska (Denali National Park) and Greenland (Thule and Summit Station). Fallout from the accident at these sites could potentially be used as a time marker in future studies of ice and snow samples from these areas, just as fallout from weapons testing and the Chernobyl incident are used to date samples from 1958-1963 and 1986, respectively. Such future applications rely on immediate data collection to establish the pattern and concentration of fallout, and to identify the Fukushima horizon based on "signatures" of short-lived isotopes, so that later samples collected after the shorter-lived isotopes have decayed can be identified. This study will also provide insight into transport pathways of other atmospheric materials and pollutants from Asia to Alaska and Greenland. This project incorporates the participation of several graduate students in collecting samples at all three field locations, including students enrolled in the Dartmouth Polar Environmental Change IGERT program. An undergraduate student will participate in the Alaska fieldwork and the laboratory analyses.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
During the summer of 2011, glacier snow and ice samples were collected during expeditions to the Kahiltna Glacier in Denali National Park (Alaska), Camp Century on the Greenland Ice Sheet (NW Greenland), and the Summit of the Greenland Ice Sheet (central Greenland). At each site, 2-3 snow pits were excavated and sampled to measure snow chemistry, particularly radioactive fallout from the March, 2011 Fukushima Dai-ichi nuclear power plant meltdown in Japan. We found clear evidence of the Fukushima fallout at all three Arctic glacier sites, confirming the widespread transport and deposition of radioactive cesium in the Arctic. We measured a total 137Cs flux of 635 Bq/m2 at Denali, 97 Bq/m2 at Camp Century, and 26 Bq/m2 at Summit, Greenland. The identification of 134Cs at these same sites confirms that the radioactive cesium is from the Fukushima accident and not from previous atmospheric nuclear weapons tests or the Chernobyl nuclear accident. Atmospheric transport modeling studies indicate that the fallout was transported to Greenland via the Bering Sea and eastern Canadian Arctic. The modeled transport path took approximately 3 weeks, and is supported by continuous air monitoring measurements of radioactive cesium at Summit, Greenland. The deposition of radioactive fallout in Denali was likely enhanced by a strong, stationary storm system that rotated over the Aleutian Islands for several days after the Fukushima accident, combined with enhanced rainfall as the storm impacted the Alaska Range Mountains.
Interestingly, our results show a 20-fold higher deposition of radioactive cesium to Denali and Camp Century than indicated by advanced atmospheric transport models. This discrepancy is likely due to erroneously low estimates of the initial amount of radioactive cesium emitted during the Fukushima accident. Thus, this research may help to place constraints on the amount of radiation released during this accident, with implications for human health particularly in Japan. Furthermore, this study constrains the radioactive fallout flux for future potential research investigating the ecological impact of this accident in the Arctic.
This is the first conclusive evidence that radioactive fallout from the Fukushima accident impacted the Arctic region. This tragic accident provides a clear example of how Asian pollution is transported into the Arctic every year, primarily during springtime, and provides critical information about pollution transport paths and deposition rates. Asia is the primary source of many atmospheric pollutants in the Arctic, including lead and mercury. Furthermore, this study has shown conclusively that the Fukushima fallout horizon is identifiable in Arctic snow and ice, and can serve as a critical absolute time marker in future Arctic ice core studies.
This study provided a critical educational research opportunity for one Dartmouth undergraduate student who participated in all aspects of the research, including field sample collection and laboratory data analyses. One graduate student benefited from a student mentoring opportunity during the Denali fieldwork, and this project served as a focus for six Dartmouth Polar IGERT (Integrated Graduate Education and Research Traineeship) graduate students who collected the samples at Summit, Greenland. Finally, this research catalyzed new research collaborations between the PI, an early career scientist, and four polar researchers.
Last Modified: 09/29/2012
Modified by: Erich Osterberg
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