The borehole strain meter at Wushi station recorded obvious anomaly before Jiashi MS= 6.8 earthquake occurred on February 24, 2003. Its features are as follows. j Anomaly types are complete. The trend anomaly, short-...The borehole strain meter at Wushi station recorded obvious anomaly before Jiashi MS= 6.8 earthquake occurred on February 24, 2003. Its features are as follows. j Anomaly types are complete. The trend anomaly, short-term anomaly, short-imminent anomaly and exponential anomaly appeared 19 months, 56 days, 4 days, and more than 1 month before the event, respectively; k Anomaly is large in magnitude. The maximal magnitude of strain anomaly is 1.7×10?5, which is rare in the past 20-year observation records at Wushi station; l Strain rate fluctuates sharply with obvious alternation of tension and compression. According to the magnitude of strain anomaly, time of expo- nential anomaly appearance and regional features of recorded anomaly, we could predict the magnitude, occur- rence time and potential region to a certain degree.展开更多
The Kunlunshan Mountain Ms8.1 earthquake, occurred in Nov.14, 2001, is the first event with magnitude more than 8 in the China earthquake monitoring history, specifically at the beginning of digital techniques in prec...The Kunlunshan Mountain Ms8.1 earthquake, occurred in Nov.14, 2001, is the first event with magnitude more than 8 in the China earthquake monitoring history, specifically at the beginning of digital techniques in precursor monitoring networks. Any investigation of recorded data on this earthquake is very important for testing the operation of the digital monitoring networks and understanding the preparation, occurrence, and adjustment of stress/strain of strong continental earthquakes. In this paper we investigated the coseismic response changes of well water level of groundwater and volume strain meter of bore hole in digital earthquake monitoring network of Capital area and its vicinity, due to the Nov.14, 2001 Ms8.1 Kunlun Mountain earthquake. The responding time, shapes or manners, amplitudes, and lasting time of well water level and strain-meters to seismic wave are studied in comparison. Then we discussed the possibility that the response changes of groundwater to strong distant earthquakes can be understood as one kind of observing evidence of stress/strain changes induced by distant earthquake.展开更多
文摘The borehole strain meter at Wushi station recorded obvious anomaly before Jiashi MS= 6.8 earthquake occurred on February 24, 2003. Its features are as follows. j Anomaly types are complete. The trend anomaly, short-term anomaly, short-imminent anomaly and exponential anomaly appeared 19 months, 56 days, 4 days, and more than 1 month before the event, respectively; k Anomaly is large in magnitude. The maximal magnitude of strain anomaly is 1.7×10?5, which is rare in the past 20-year observation records at Wushi station; l Strain rate fluctuates sharply with obvious alternation of tension and compression. According to the magnitude of strain anomaly, time of expo- nential anomaly appearance and regional features of recorded anomaly, we could predict the magnitude, occur- rence time and potential region to a certain degree.
基金supported by Natural Science Foundation of China(41274061 and 40374019)
文摘The Kunlunshan Mountain Ms8.1 earthquake, occurred in Nov.14, 2001, is the first event with magnitude more than 8 in the China earthquake monitoring history, specifically at the beginning of digital techniques in precursor monitoring networks. Any investigation of recorded data on this earthquake is very important for testing the operation of the digital monitoring networks and understanding the preparation, occurrence, and adjustment of stress/strain of strong continental earthquakes. In this paper we investigated the coseismic response changes of well water level of groundwater and volume strain meter of bore hole in digital earthquake monitoring network of Capital area and its vicinity, due to the Nov.14, 2001 Ms8.1 Kunlun Mountain earthquake. The responding time, shapes or manners, amplitudes, and lasting time of well water level and strain-meters to seismic wave are studied in comparison. Then we discussed the possibility that the response changes of groundwater to strong distant earthquakes can be understood as one kind of observing evidence of stress/strain changes induced by distant earthquake.
