Mechanism of Phreatic Eruptions at Aso Volcano Inferred from Near-Field Broadband Seismic Observations
1996; American Association for the Advancement of Science; Volume: 273; Issue: 5275 Linguagem: Inglês
10.1126/science.273.5275.642
ISSN1095-9203
AutoresSatoshi Kaneshima, Hitoshi Kawakatsu, Hirotoshi Matsubayashi, Yasuaki Sudo, Tomoki Tsutsui, Takao Ohminato, Hisao Ito, Koichi Uhira, Hitoshi Yamasato, Jun Oikawa, Minoru Takeo, Takashi Iidaka,
Tópico(s)Seismology and Earthquake Studies
ResumoBroadband seismometers deployed at Aso volcano in Japan have detected a hydrothermal reservoir 1 to 1.5 kilometers beneath the crater that is continually resonating with periods as long as 15 seconds. When phreatic eruptions are observed, broadband seismograms elucidate a dynamic interplay between the reservoir and discharging flow along the conduit: gradual pressurization and long-period (approximately20 seconds) pulsations of the reservoir during the 100 to 200 seconds before the initiation of the discharge, followed by gradual deflation of the reservoir concurrent with the discharging flow. The hydrothermal reservoir, where water and heat from the deeper magma chamber probably interact, appears to help control the surface activity at Aso volcano.
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