Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma
The two-dimensional electrical resistivity structure beneath Naruko volcano was determined using magnetotelluric soundings. The resulting model shows that a prominent conductor exists through the middle crust to the uppermost mantle beneath the volcano. The location of the conductor agrees closely w...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2010-01-01
|
| Series: | International Journal of Geophysics |
| Online Access: | http://dx.doi.org/10.1155/2010/738139 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832548870271270912 |
|---|---|
| author | Koichi Asamori Koji Umeda Yasuo Ogawa Teruki Oikawa |
| author_facet | Koichi Asamori Koji Umeda Yasuo Ogawa Teruki Oikawa |
| author_sort | Koichi Asamori |
| collection | DOAJ |
| description | The two-dimensional electrical resistivity structure beneath Naruko volcano was determined using magnetotelluric soundings. The resulting model shows that a prominent conductor exists through the middle crust to the uppermost mantle beneath the volcano. The location of the conductor agrees closely with a seismic low-velocity zone. Low-frequency microearthquakes occur near the conductor around the Moho depth. The cutoff depth of crustal earthquakes is coincident with the upper boundary of the conductor, implying that the conductor has a temperature appreciably higher than 400∘C. Furthermore, new helium isotope data from hot springs around the volcano were obtained. The spatial distribution of the observed 3He/4He ratios reveals the extent of mantle-derived materials beneath Naruko volcano. Consequently, it is apparent that the conductor determined beneath the volcano reflects the presence of high-temperature mantle-derived materials such as magmas and/or related fluids derived from active magmatism in the northeastern Japan subduction zone. |
| format | Article |
| id | doaj-art-2ac12eb769f64b83b2f74c221bb169e1 |
| institution | Kabale University |
| issn | 1687-885X 1687-8868 |
| language | English |
| publishDate | 2010-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Geophysics |
| spelling | doaj-art-2ac12eb769f64b83b2f74c221bb169e12025-02-03T06:12:44ZengWileyInternational Journal of Geophysics1687-885X1687-88682010-01-01201010.1155/2010/738139738139Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal MagmaKoichi Asamori0Koji Umeda1Yasuo Ogawa2Teruki Oikawa3Tono Geoscientific Research Unit, Geological Isolation Research and Development Directorate, Japan Atomic Energy Agency, 959-31, Jorinji, Izumi, Toki 509-5102, JapanTono Geoscientific Research Unit, Geological Isolation Research and Development Directorate, Japan Atomic Energy Agency, 959-31, Jorinji, Izumi, Toki 509-5102, JapanVolcanic Fluid Research Center, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro, Tokyo 152-8551, JapanTono Geoscientific Research Unit, Geological Isolation Research and Development Directorate, Japan Atomic Energy Agency, 959-31, Jorinji, Izumi, Toki 509-5102, JapanThe two-dimensional electrical resistivity structure beneath Naruko volcano was determined using magnetotelluric soundings. The resulting model shows that a prominent conductor exists through the middle crust to the uppermost mantle beneath the volcano. The location of the conductor agrees closely with a seismic low-velocity zone. Low-frequency microearthquakes occur near the conductor around the Moho depth. The cutoff depth of crustal earthquakes is coincident with the upper boundary of the conductor, implying that the conductor has a temperature appreciably higher than 400∘C. Furthermore, new helium isotope data from hot springs around the volcano were obtained. The spatial distribution of the observed 3He/4He ratios reveals the extent of mantle-derived materials beneath Naruko volcano. Consequently, it is apparent that the conductor determined beneath the volcano reflects the presence of high-temperature mantle-derived materials such as magmas and/or related fluids derived from active magmatism in the northeastern Japan subduction zone.http://dx.doi.org/10.1155/2010/738139 |
| spellingShingle | Koichi Asamori Koji Umeda Yasuo Ogawa Teruki Oikawa Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma International Journal of Geophysics |
| title | Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma |
| title_full | Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma |
| title_fullStr | Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma |
| title_full_unstemmed | Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma |
| title_short | Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma |
| title_sort | electrical resistivity structure and helium isotopes around naruko volcano northeastern japan and its implication for the distribution of crustal magma |
| url | http://dx.doi.org/10.1155/2010/738139 |
| work_keys_str_mv | AT koichiasamori electricalresistivitystructureandheliumisotopesaroundnarukovolcanonortheasternjapananditsimplicationforthedistributionofcrustalmagma AT kojiumeda electricalresistivitystructureandheliumisotopesaroundnarukovolcanonortheasternjapananditsimplicationforthedistributionofcrustalmagma AT yasuoogawa electricalresistivitystructureandheliumisotopesaroundnarukovolcanonortheasternjapananditsimplicationforthedistributionofcrustalmagma AT terukioikawa electricalresistivitystructureandheliumisotopesaroundnarukovolcanonortheasternjapananditsimplicationforthedistributionofcrustalmagma |