Joint Passive/Controlled Source Seismic Experiment Across Taiwan

Abstract

Scientists who study Earth structures and interactions at tectonic plate boundaries illuminate the three‐dimensional (3‐D) subsurface primarily through passive or active source seismic studies. In passive source studies, natural earthquakes are observed through arrays of seismic stations, allowing seismologists to image structures at depth and infer physical properties of the Earth. In active (controlled) source studies, scientists provide an artificial seismic source to be recorded by seismic networks, allowing more detailed views of fine‐scale structures buried within plate boundaries. The use of “continuous” modes on large‐storage‐capacity seismic recording systems enables seismologists to blur traditional lines between active and passive source seismology in regions of high earthquake activity. In addition to generating seismograms from controlled sources, a deployed dense array can record local and teleseismic earthquakes with exceptionally coherent signals across its aperture. As a result of such joint recording, the scientific value of the collected data increases. Moreover, whether or not the seismic sources are natural or engineered becomes less of a factor for data storage, sorting, and analysis methods. Local earthquakes can supplement controlled sources, multichannel processing and imaging methods traditionally used in active seismic studies become amenable to dense sets of passive source data, and active source data with known source origin times and locations are easily incorporated into regional seismic 3‐D tomography and earthquake location studies.

Broad‐band Rayleigh wave tomography of Taiwan and its implications on gravity anomalies

“…Besides two major permanent seismic networks, the Central Weather Bureau Broad‐Band network (CWBBB), operated by the Central Weather Bureau, Taiwan, and the Broadband Array in Taiwan for Seismology (BATS), operated by the Institute of Earth Science, Academia Sinica, we have incorporated data from three east‐west linear arrays from a temporary broadband network deployed by the TAIGER project [ Okaya et al , 2009]. In total, we have collected continuous data from 85 stations, including 25 CWBBB stations, 14 BATS stations and the other 46 from TAIGER arrays.…”

The Deep Electrical Structure of Southern Taiwan and Its Tectonic Implications

“…The TAIGER (Taiwan Integrated Geodynamics Research) project has been investigating the tectonics of Taiwan since 2004 with the goal of addressing these issues. The TAIGER project (Wu and US/Taiwan TAIGER teams 2007; Okaya et al 2009) aims to provide a detailed study of the Taiwan orogen through an integrated program of petrophysics, geodynamic modeling, seismology and magnetotellurics (MT). The initial results of the TAIGER MT studies in central Taiwan were described by Bertrand et al (2009) and the profile location is shown in Fig.…”

Significant crustal structural variation across the Chaochou Fault, southern Taiwan: New tectonic implications for convergent plate boundary

“…3) (Okaya et al, 2009). A total of 39 broadband stations with digital three-component instruments were deployed between 26 March 2009 and 2 June 2009.…”