HR: 1340h
AN: OS53A-0976    [Abstracts]
TI: The MicrOBS study around Taiwan
AU: * Liang, C
EM: leecs@mail.ntou.edu.tw
AF: Institute of Applied Geosciences, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, 202, Taiwan
AU: Lee, C
EM: leecs@mail.ntou.edu.tw
AF: Institute of Applied Geosciences, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, 202, Taiwan
AB: Since 2005, we have managed 16 MicrOBS, designed by the French IFREMER, to study the earthquake and crustal structute around Taiwan. The instrument itself is very light (20 kgs) and easy to operate. This OBS has a measuring period up to 2 weeks in the seafloor. We have conducted the works, aiming to get a better understanding of the ¡§marine¡¨ earthquakes, from the in situ small event to the big earthquake. For example, a study of the seismic gaps in the offshore region becomes workable as compare with the time when we only have the land seismological instruments. We have also used this instrument to obtain a detail study of the gas hydrate and free gas zone. Whenever a large seismic source is available, we then conduct the local and regional crustal studies, such as in the Philippine Sea and South China Sea. In the last 3 years, we have directed 285 deployments of MicrOBS around Taiwan. More than 80 per cent of the natural earthquakes in Taiwan (in an average of about 15,000 events of Mm greater than 2 events per year) were occurred in offshore area. Big earthquakes (i.e. Mm greater than 6) are more often happen in the offshore area than that in the onshore region. Therefore, the tools (MicrOBS and OBS) to measure these ¡§marine¡¨ earthquakes become essential to understand the character and origin of crustal dynamics, particularly in the seismogenic zone.
DE: 4200 OCEANOGRAPHY: GENERAL
DE: 4219 Continental shelf and slope processes (3002)
DE: 4243 Marginal and semi-enclosed seas
DE: 8110 Continental tectonics: general (0905)
DE: 8169 Sedimentary basin processes
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting