3:30 PM - 4:30 PM
[S12-P-05] Anomalies of astronomical time-latitude observations before strong earthquake and discussions on the problems of its application
Strong earthquake may create a large number of casualties and huge property losses. Due to the complexity of crustal structure and movement, the geophysical process during the gestation and occurrence of earthquake is extremely complex. So it is very difficult to forecast an earthquake in advance. To find effectual earthquake precursors is one of the key for meliorating earthquake prediction. A phenomenon that short-term anomalies appeared in residuals of astronomical time and latitude observations before major earthquakes, which occurred in regions around the astrometric instruments, was discovered by Chinese astronomers after Tangshan Earthquake in 1976. The phenomenon was called anomalies of residuals of astronomical time and latitude observations (ATLR). The major characteristics of the phenomenon have been studied preliminarily. ATLR anomalies may be from the variation of the vertical, which is the datum line of such astrometric instruments, due to the motion of underground mass.
The possibility that using the observations to provide information for strong earthquakes in advance has been researched and related tests to provide forecast information have made in China. Present results and tests showed that the phenomenon would possibly become a kind of significant short-term earthquake precursors. However, observations of one instrument can only reflect the vertical variations within a certain range around the instrument, so ATLR of one station cannot afford the information of position and magnitude of an earthquake. To set up an network using seemly astrometric telescopes in seismogenetic zone will be needful for finding significant forecasting information. The new Digital Zenith Telescope (DZT) which has characters of high precision, robotization, miniaturization and low cost was made in China recently years. DZT is propitious to set up such network. The scheme on setting up network is put forward. The notions and problems related to network are discussed.
The possibility that using the observations to provide information for strong earthquakes in advance has been researched and related tests to provide forecast information have made in China. Present results and tests showed that the phenomenon would possibly become a kind of significant short-term earthquake precursors. However, observations of one instrument can only reflect the vertical variations within a certain range around the instrument, so ATLR of one station cannot afford the information of position and magnitude of an earthquake. To set up an network using seemly astrometric telescopes in seismogenetic zone will be needful for finding significant forecasting information. The new Digital Zenith Telescope (DZT) which has characters of high precision, robotization, miniaturization and low cost was made in China recently years. DZT is propitious to set up such network. The scheme on setting up network is put forward. The notions and problems related to network are discussed.