Preliminary result of magnetotelluric soundings in the fold-thrust belt of Taiwan and possible detection of dehydration

Seismo-Ionospheric Precursors of the 26 December 2006 M 7.0 Pingtung Earthquake Doublet

“…8). Typical conductivity at about 100 km altitude for the mid-latitude areas, such as Taiwan, daytime ionosphere is about 100 -300 S m -1 (or mho m -1 ) (Kelly 1989) and that for the lithosphere ranges from 0.1 to 1 S m -1 at about 40 km depth (see papers listed in Chen and Chen 1998). Freund (2000) show that mobile positive holes can be activated in the crust by microfractures during the dilatancy stage of earthquake preparation (Bolt 1999), and diffusion and outflow of these holes further generate strong underground currents and high electric fields on the Earth surface.…”

Crustal Resistivity Anomalies Beneath Central Taiwan Imaged by a Broadband Magnetotelluric Transect

“…Clean time-series data were used for remote reference processing (Gamble et al 1979). Remote reference processing improved the data quality at periods longer than 1 s. The MT dataset used in this study combined previous surveys (Chen and Chen 1998, 2000 with more recent data collected as part of the international TAIGER-MT project. In total, more than 80 MT soundings were collected in central Taiwan.…”

Analysis of site effects in magnetotelluric data by using the multifractal detrended fluctuation analysis

“…The magnetotelluric (MT) method is a technique measuring the variation in the EM field on the Earth's surface for geological mapping of the subsurface structures (Chen and Chen, 1998;Chen et al, 2007). The MT data include two electric (E x , E y ) and two magnetic (H x , H y ) components, both in horizontal layouts with the north-south and east-west directions, and one vertical magnetic (H z ) component.…”