Seismic observations in the DPRI 1800 m borehole drilled into the Nojima Fault zone, south-west Japan

Citation
K. Nishigami et al., Seismic observations in the DPRI 1800 m borehole drilled into the Nojima Fault zone, south-west Japan, ISL ARC, 10(3-4), 2001, pp. 288-295
Citations number
8
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
ISLAND ARC
ISSN journal
1038-4871 → ACNP
Volume
10
Issue
3-4
Year of publication
2001
Pages
288 - 295
Database
ISI
SICI code
1038-4871(200109/12)10:3-4<288:SOITD1>2.0.ZU;2-L
Abstract
Seismometers were installed at three depths in the Disaster Prevention Rese arch Institute, Kyoto University (DPRI) 1800 m borehole drilled into the No jima Fault zone, southwest Japan. The waveforms recorded by these seismomet ers are rather simple compared with those recorded at the DPRI 800 m boreho le or on the ground surface. These data should be well suited for detecting fault zone-trapped waves and estimating the fault zone structure and its t emporal variation related to the healing process of the ruptured fault. Typ ical waveforms trapped in the fault zone were observed by a surface seismog raphic array across the Nojima Fault just after the 1995 Hyogo-ken Nanbu ea rthquake (Kobe earthquake). Among the wave data recorded in the DPRI 1800 m borehole, however, clear evidences of fault zone-trapped waves have not ye t been found, and further studies are continuing. The present study outline s the observation system in the DPRI 1800 m borehole, which will make it ea sier to access and analyze the borehole data.