Earthquake Related Anomalies in Geomagnetic Data
Speaker: Yuan-Chung Yang Advise: Horng-Yuan Yen
Abstract
Seismo-magnetic anomalies induced from the momentary existence of current and/or high-conductivity materials have been widely reported. There are many way to analyze the relationship between geomagnetic data and seismic events. According to the previous studies, frequency band of 0.1-0.01Hz is the earthquake-related band, in which the data could be affected by the upcoming earthquakes. (Wen at el., 2012) used the cross correlation value between amplitude of the earthquake-related frequency (0.1-0.01Hz) and the comparable frequency (0.01-0.001Hz), for isolated amplitude enhancements as indexes of determination associated with seismo-magnetic anomalies. (Chen at el., 2015) used the concept of Parkinson vector which is a calculated vector that point toward high conductivity materials to reveal the high conductivity area occurred during the fault zone. Azimuth distribution constructed from the entire Parkinson vectors during the observation period is utilized to estimate the persistent background at each station. The result show that high-conductivity materials appeared in areas (121.25°E, 23.70°N) and about 15-25Km in depth which is 32Km away from the epicenter and covers the hypocenter depth. These researches shed lights on the location and hypocenter depths of forthcoming earthquakes via analizing the effect of earthquake on geomagnetic field.
Reference
Wen, S., et al. "Magnetic storm free ULF analysis in relation with earthquakes in Taiwan." Natural Hazards and Earth System Science 12.5 (2012): 1747-1754.
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