研究期間：10108~10207;There are two fatal limitations for the past studies of earthquake precursors -- the rarity of great earthquakes and the low coverage of instrumental observatories. Taiwan is a small island located at the western Pacific Ocean. It is the good fortune that we have unfortunately frequent seismicity. So that, if we can construct a dense network of electromagnetic monitoring stations a lot of earthquake-induced electromagnetic phenomena, no matter precursory or co-seismic ones, will be eventually observed throughout Taiwan. This then leads to a good possibility of earthquake prediction. This project aims at arguing, based on three viewpoints of theory, experiments and field-observations, the conditions of producing the electrical polarization charges and the electric field prior to a great earthquake of a shear zone. We will set up the long-term monitoring net of electrical fields throughout the island, to record the wide-band data of the electrical fields with the frequency range from 100 to 10-4 Hz which can image hypocentral materials at various depths from few to several ten kilometers. Based on both laboratory experiments and effective medium theory of rock mechanics, we will also probe into the possibility of electrical polarization field existing before macroscopic breakdown of rocks, which might help us to elucidate the prediction feasibility of electromagnetic phenomena. Having high quality data of seismology, which is actually a consequence of the densest seismological network equipped, makes Taiwan a unique and important position in the solid earth discipline around the world. Now, frequent earthquakes and small territory are giving us another opportunity to be unique in the role of earthquake prediction among the international Earth Science community, by means of equipping Taiwan a dense observatory network of monitoring natural electrical fields.
