Observation of hydroacoustic noise at Kusatsu-Shirane volcano, Japan
Abstract
Kusatsu-Shirane volcano is a quaternary volcano situated in the central part of Japan. The volcano has repeated small phreatic explosions at the interval of several decades and those explosions have occurred at one of 3 crater lakes, Yugama, Mizugama and Karagama. More than 25 years have passed since the last eruption. In 2008, a new fumarole was found at the wall of the central crater lake, Yugama. The next eruption is of great concern. In 2008, we renewed observation system around Yugama, measuring ground temperature, air temperature, water temperature, water level and rain intensity. In the hope of detecting temporal change of the volcanic activity, such as very shallow earthquakes or fumaroles at the bottom of the crater, we also began observation of hydroacoustic noise with hydrophones at 2 sites of the crater lake, one on the shore and the other in the central. The noise is recorded with a portable digital IC recorder Sony ICD-SX900 at a frequency of 8000 Hz. The data storage of the IC recorder is as large as 4 GB, which enables us to record the acoustic signal for 2 continuous months.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.V51C1713Y
- Keywords:
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- 8419 VOLCANOLOGY / Volcano monitoring;
- 8424 VOLCANOLOGY / Hydrothermal systems;
- 8494 VOLCANOLOGY / Instruments and techniques