Dr. Jann-Yenq Liu’s Research on Ionospheric Earthquake Precursory Signs Has Attracted International Attention
Dr. Jann-Yenq Liu, a space scientist and Professor at the Graduate Institute of Space Science and Engineering at National Central University, has devoted his time and effort to studying ionospheric earthquake precursors for more than twenty-five years. Dr. Liu was rank 11th among the top twenty authors with the largest number of scientific articles on seismic events published by the International Seismological Centre (ISC) in 2019.
The ISC is a non-governmental organization (NGO) established in 1964 with the assistance of the United Nations Educational, Scientific and Cultural Organization (UNESCO). The ISC is the very first organization that collects the data of seismicity worldwide. It is recognized that the seismic data possessed by the ISC is the most chronic, the most stable, and the most reliable one in the world. Among the rank of top 20 authors in the ISC Event Bibliography, the first ten authors are the most prominent seismologists around the globe. To be ranked 11th “was an utter surprise to many professionals and scientists,” described Dr. Liu.
Dr. Liu originally specialized in the coupling of the ionosphere and the magnetosphere at high latitudes. In 1990, he returned to Taiwan and began to conduct research related to his homeland. Taiwan is located in the area under the region of the equatorial ionization anomaly in the ionosphere, and earthquakes also frequently occur in this area. A large amount of data on co-seismic ionospheric disturbances suggests that precursory signals might be observed before large earthquakes, and various types of energy could be released or leaked during the period of the stress accumulation of faults before large earthquakes. Dr. Liu states that the “electromagnetic response” in space is the key to observing earthquake precursors (i.e., electromagnetic foreshocks).
Dr. Liu had worked for almost seven years on the research of ionospheric earthquake precursors, and his papers on seismo-ionospheric precursors were published by Geophysical Research Letters (GRL) not long after the Chi-Chi Earthquake in 1999. The discoveries of Liu et al. (GRL 2000; GRL 2001) marked the first time that human beings could observe ionospheric earthquake precursors three to four days before the occurrence of earthquakes and locate possible forthcoming large earthquakes. Six years later, for the first time in human history, his research team reported ionospheric tsunami disturbances (or iononami) triggered by the 2004 M9.3 Sumatra Earthquake, and their report was published by the Journal of Geophysical Research (JGR) (Liu et al., JGR 2006). In 2011, with dense ground-based GPS receivers in Taiwan and Japan, Dr. Liu reported ionospheric tsunami disturbances induced by the Tohoku Earthquake in great detail and observed from space for the first time in human history the epicenter where a tsunami was formed (Liu et al., JGR 2011). Dr. Liu not only created the studies of seismo-ionospheric precursors but also initiated the development of the ionospheric tsunami early warning system.
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