Abstract
Repeated precise leveling in the earthquake swarm area of Ontake, central Japan has revealed uplift of 3-6 mm in proximity to the epicentral region of the most active earthquake cluster in 2002-2004. Although the uplift is small, the vertical displacement is significant even considering leveling error. This uplift is associated with increases in 3He/4He ratios and CO2 δ13C values at a mineral spring in the region, indicating an upper mantle contribution. A region of low resistivity at a depth of 2 km beneath the uplift area has also been inferred, suggesting that the observed uplift is related to changes in a shallow seismogenic layer due to increased hydrothermal input from the earthquake swarm area.
Original language | English |
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Pages (from-to) | e45-e48 |
Journal | earth, planets and space |
Volume | 56 |
Issue number | 12 |
DOIs | |
Publication status | Published - 2004 |
Externally published | Yes |
Keywords
- Ground uplift
- He/He ratio δC, CO
- Low resistivity layer
- Ontake earthquake swarm
- Precise leveling
- Shallow seismogenic layer
ASJC Scopus subject areas
- Geology
- Space and Planetary Science