Introduction to the Broadband Array in Taiwan for Seismology (BATS) Wen-Tzong Liang* Chun-Chi Liu Bor-Shouh Huang Institute of Earth Sciences, Academia Sinica, Taiwan Waveform Data Management Workshop Oct, 2007

Overview Taiwan Tectonics Broadband Array in Taiwan for Seismology Network Operation Portable Units Future Plans

Taiwan Tectonics Pacific Plate Eurasia Plate Taiwan China Japan Australia Philippine Philippine Sea plate Taiwan is located in the Western Pacific region between Japan and Philippine to the east of mainland China. Tectonically, Taiwan is located on the convergent plate boundary zone between the Eurasian Plate and the Philippine Sea Plate.

Taiwan Tectonic Setting Manila Trench South China Sea CWB M L  3.5 Kuo, 2003 IES DMC 80 mm/y r

Taiwan Seismicity MLML No. of Earthquakes Oct – Sep Mc ~ 2.5 Data Source: IES& CWB > 30 (M L >2.5)/day

TEC Station Information System

Broadband Array in Taiwan for Seismology (BATS) IES Project was initiated by the IES in 1992 Started constructing its first station in 1994 Routinely inverting CMT solutions since 1996 Join FDSN as a member network (open data) An organized BATS DC established in 2001 CWB CWB added BB stations since late BB stations operated by IES/CWB in 2007

BATS Stations 1 GSN station (TATO)  KS 5400i BATS/IES: 21  STS2/STS1/Trillium240 BATS/CWB: 32  Guralp 3ESP/40T/3T 54 Permanent BB Stations in the Taiwan Region

Instrumentation BATS-IES STS1/ STS2 /CMG3TB/ Trillium 240 EpiSensor Q680/ Q4120/ Q330/ Q330HR Frame Relay/ Microwave/ Satellite BATS-CWB CMG3ESP/ CMG40T/ CMG3T EpiSensor Frame Relay/ Satellite transmission

Station Condition TDCB Techi YULB Yuli NACB Taroko STS-1 STS-2 marble schist slate STS-2

BATS Stations High seismicity in the offshore region of eastern and southern Taiwan, where is seriously lacking station coverage The only way to enlarge the array aperture is to deploy OBS or to exchange data with various operating agents

Real-Time Data Exchange NIED  10-minutes mseed files (file-based)  seedlink data streams (packet-based)  4 F-Net stations 2 BATS stations IRIS  orb2orb data streams  Data of 7 BATS stations is accessible to public through IRIS facilities in a real-time manner

BATS + F-Net Stations

Data Acquisition Systems Real-time operation Earthworm System IES/CWB  2001 IES/CWB  USGS Software/ ISTI Antelope System IES  2006 IES  Commercial Package/ BRTT

Earthworm System

Antelope System

Portable Seismic Arrays/ IES Tarim, China Taiwan Tibet, China 2005~ Vietnam 2007~ Georgia STS-2/ Trillium Broadband Sensors Reftek/ Q bit Digitizers

Portable Seismic Arrays/BATS Georgia 2007~ Hi-CLIMB Tarim Northern Vietnam 2005~ TAIGER 2006~ STTA 2005~

IES Broadband OBS Experiment The 1st deployment of BB OBS experiment in the eastern offshore region Kuo and Chi, Sep

BATS Web Services Regional Quick CMT ReportWaveform Viewing and Download

BATS CMT Solutions

Seismotectonic Patterns Kao and Jian, 2001 Regional and local seismotectonic patterns

New Challenges to BATS Ambient noise reduction – borehole stations Expanding array aperture to obtain higher resolution of deep structures Extending observable frequency band of signals Providing better web services to the community

New Observations of BATS Low-Gain Sensors (Velocity type Accelerometer) Borehole Strainmeters (Dynamic Strain) High Sampling Rate Continuous GPS (Horizontal) Superconducting Gravimeter (Vertical) Magnetotelluric (Electromagnetic properties)

Future Plans On-line BATS event waveform database Collaborated with the ASCC/ ASGC for modern IT applications Toward integrated geophysical observatories Seeking for international collaboration on data exchange and tectonic studies Contributing to Pacific-Asia Risk Mitigation

Thank you!