The Hawaii-2 Observatory: Observation of Nanoearthquakes
The Hawaii-2 Observatory: Observation of Nanoearthquakes
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Hawaii-2 天文台:纳米地震观测
DOI:
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发表时间:
2003
期刊:
影响因子:
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通讯作者:
R. Butler
中科院分区:
文献类型:
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作者:
R. Butler
The Hawaii-2 Observatory (H2O; http://www.iris.edu/GSN/) was established on the seafloor between Hawaii and California (Figure 1) in 1998 using the retired ATT Duennebier et al. , 2002; Harris and Duennebier, 2002; Pettit et al. , 2002). This is the first undersea seismic station in the Global Seismographic Network. The on-site instrumentation includes a broadband Guralp CMG-3 and 4.5 Hz Geospace HS1 geophones, buried 0.5 m into the sea-floor mud, and an OAS E2PD hydrophone 0.5 m above the seafloor. All of the data are natively sampled at 160 sps continuously and sent via the Hawaii-2 cable to Oahu, where they are distributed by the University of Hawaii to IRIS. Data are available in real-time via a Live Internet Seismic Server (LISS) server and are being used by the Pacific Tsunami Warning Center and the National Seismic Network. In early 2002, the Ocean Drilling Program drilled a borehole through 29±1 m of sediment into basalt about 1.5 km northeast of the current H2O instrumentation as a site for a future borehole sensor (Stephen et al. , 2003).
Figure 1.
(left) The Hawaii-2 Observatory at 27° 52.916 N, 141° 59.504 W is sited 1,750 km east-northeast of Honolulu (Butler et al. , 2000). The site lies between the Murray and Molokai Fracture Zones at 4,979 m depth on predominantly terrigeneous, pelagic clay. The oceanic crust is of Eocene age (45–50 m.y.) and is normal but fast-spreading with a spreading half-rate of 7 cm/y. (top, center) The Hawaii-2 cable terminates in western Oahu and passes between Kauai and Oahu before traversing northeast toward California, (right) The abyssal bathymetry is locally flat in a ∼5,000 km2 region with abyssal hills rising less than 500 m high at about 30 …