Study On Spatio - Temporal Symmetry Of Taiwan Earthquake Disaster

Taiwan is located in the west bank of the Pacific seismic, its geological activity is intense, and is an earthquake prone area. The earthquake disasters can course larger number casualties and more economic losses because of its dense population and developed industry. So, the study on trends and reasons for earthquakes of Taiwan has far-reaching significance.This research selected and arranged the historical earthquakes in Taiwan from 1900 to 2013, using the commensurability calculations, butterfly structure diagram, commensurability structure, space symmetry method, latitudinal and longitudinal migration and so on, this research revealed the space-time symmetry on Taiwan, the southeast seismic belt, the northeast seismic belt and the western seismic belt of earthquakes, determined its future trends. The main conclusions showed that:(1)During 1900 to 2013, different magnitudes of the earthquakes occurred in Taiwan showed good time symmetry. Taiwan has a strong signal of the occurrence of (Ms≥7.1)earthquake in 2015 and 2016, which is the same as the northeast seismic belt (Ms≥6.2) earthquake; the southeast seismic belt and the western seismic belt have a strong signal of the occurrence of earthquake in 2016,respectively Ms≥7.1 and Ms≥ 7.0 or above earthquake may occur.(2) During 1900 to 2013, different magnitudes of the earthquakes occurred in Taiwan showed three-edge spatial symmetry:① Taiwan takes 23.5°N,121.6°E as the coordinate axis, showed "Northwest-Southeast" symmetrical distribution. We judge the next epicenter location of the Ms≥7.1 earthquake approximate position would in the third quadrant which migrate to the northwest, or eastward skip little near the 2006 year;②The southeast seismic belt takes 22.95°N as the coordinate axis, showed "One North-Two South" symmetrical distribution. We judge the next epicenter location of the Ms≥7.1 earthquake approximate position would migrate to the south of 23°N and the west of 122°E areas; ③the northeast seismic belt takes 122.1°E as the coordinate axis, showed "Two West-One East" anti-symmetrical distribution. We judge the next epicenter location of the Ms≥ 6.2 earthquake approximate position would migrate to the south of 24.7°N and the west of 122.01°E; ④the western seismic belt takes 23.3°N, 120.9°E as the coordinate axis, showed "Two West-One East, Two North-One South" anti-symmetrical distribution. We judge the next epicenter location of the Ms≥7.0 earthquake approximate position would migrate to the south of 23°N and the east of 121°E areas, as well as Nantou count and Hualian city.(3)The analysis on the relevant factors:plate motion, sunspot activity, earth rotation, the ENSO events, we conclude the follow results:①The crustal stress energy which caused by the collision of Eurasian Plate and the Philippine Sea Plate affects Taiwan earthquake most; So the distribution of its earthquake showed to be SE-NW. ②The earthquake which in Taiwan is easier occurred in the decline period of sunspot activity, the ratio was as high as 55.6%、 72.7%、47.1%、53.8%.③While the earth rotation speed is slowing down and the earthquake is likely to happen in the western seismic belt. ④Besides of the western seismic belt, earthquakes of the remaining districts were prone to occurred in the El-Nino year. And its probability all above 70%, the highest is 78.8%.When the El-Nino intensity bigger, the earthquake will more serious, and it is easier to occur a harmer earthquake in the year which El-Nino and La-Nina events alternated.(4) During 1900 to 2013,generally,if Chile occurred an Ms≥8.0 earthquake, one or several Ms≥7.5 earthquakes disaster will be happened in Taiwan. In addition, there were 38-39 years correlation between Chile and Taiwan, which two both have similar construction. In the 38 years change cycle, the seismic stress of Taiwan is active, indicating that an earthquake is probably to be happened in Taiwan in recent time.This research identified the abnormal time and possible domain space of the Taiwan earthquakes in recent 10 years, enriched the disaster case, and provided a reference for earthquake prevention and disaster reduction.