| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2012: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
|
|---|
| Outline of Final Research Achievements |
We investigated characteristics of the volcanic tremor occurred at Shinmoedake volcano, Japan. Detailed analysis for the seismograms obtained by two seismic arrays and stations deployed near the volcano provided the source locations and focal mechanism of the tremor. We observed changes in the seismic ray direction during a volcanic tremor sequence and inferred two major sources of the tremor from the slowness vectors of the approaching waves. One was located in a shallow region beneath the crater. The other was found in a direction N30W from the array, pointing to a location above a pressure source. The time evolution of the tremor suggests that instability occurs at the edge of the conduit. The fine volcanic tremor structure suggests an interaction between conduits located in both deep and shallow depths. Source models were also estimated from observed radiation pattern of the tremor at the seismic network. The sources were modeled by almost horizontal tesile cracks.
|
