| Abstract: | Time-series sensor data reveal significant short-term and seasonal variations of magmatic CO2 in soil over a 12 month period in 1995-1996 at the largest tree-kill site on Mammoth Mountain, central-eastern California. Short-term variations leading to ground-level soil CO2 concentrations hazardous and lethal to humans were triggered by shallow faulting in the absence of increased seismicity or intrusion, consistent with tapping a reservoir of accumulated CO2, rather than direct magma degassing. Hydrologic processes closely modulated seasonal variations in CO2 concentrations, which rose to 65%-100% in soil gas under winter snowpack and plunged more than 25% in just days as the CO2 dissolved in spring snowmelt. The high efflux of CO2 through the tree-kill soils acts as an open-system CO2 buffer causing infiltration of waters with pH values commonly of < 4.2, acid loading of up to 7 keqH+.ha-1.yr-1, mobilization of toxic Al3+, and long-term decline of soil fertility. |
| Genre: | Article |
| ProdID: | 70020406 |
| Citation Author: | McGee, K. A.; Gerlach, T. M. |
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| Citation End Page: | 466 |
| Citation Issue: | 5 |
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| Citation Language: | English |
| Citation Larger Work Title: | Geology |
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| Citation Number Of Pages: | 4 |
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| Citation Search Results Text: | Annual cycle of magmatic CO2 in a tree-kill soil at Mammoth Mountain, California: implications for soil acidification; 1998; Article; Journal; Geology; McGee, K. A.; Gerlach, T. M. |
| Citation Start Page: | 463 |
| Citation Volume: | 26 |
| Citation Year: | 1998 |
| Type: | citation/reference |
| Text: | Annual cycle of magmatic CO2 in a tree-kill soil at Mammoth Mountain, California: implications for soil acidification; 1998; Article; Journal; Geology; McGee, K. A.; Gerlach, T. M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1998 00:00 -0600 |
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