The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan M_S 8. 0 earthquake is less than that of the Menglian earthquake. The ...The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan M_S 8. 0 earthquake is less than that of the Menglian earthquake. The number of anomalies and stations associated with the Wenchuan earthquake increased in the early stage of the short-term range,as opposed to the later period for the Menglian and Lijiang earthquakes. Most of the medium term anomalies occurred two to three years before the Wenchuan earthquake,when the number of anomaly stations and items was eleven,and a great change appeared in the observation values in about half of the stations ( items ) . However,for the Menglian earthquake,medium term anomalies happened one to two years before the earthquake, the number of abnormal stations and items reached 20,and a sharp change appeared in the observation values six months to one year before the earthquake in about 30 percent of the stations or items. In the epicenter and the nearby area,the macroscopic abnormalities started 3 years before the Wenchuan earthquake and lasted intermittently until 1 month before the earthquake. Within 2 percent of the total area of the province,the macroscopic abnormalities accounted for 30 to 50 percent of the total number of anomalies of the Province. For the Xingtai,Tangshan,Haicheng,Songpan earthquakes,the macroscopic anomalies started two to three months before,or on the very day of the earthquakes. The common feature of the precursors between the Wenchuan and other strong earthquakes is the appearance of tremendous changes in a certain number of observation values of anomalies in the mid and short terms before all these earthquakes.展开更多
The macroscopic anomalies before and after the May 12,2008 Wenchuan M8. 0 earthquake were collected and analyzed in this paper. The credible anomalies occurring from February 1 to June 10,2008 were treated as macrosco...The macroscopic anomalies before and after the May 12,2008 Wenchuan M8. 0 earthquake were collected and analyzed in this paper. The credible anomalies occurring from February 1 to June 10,2008 were treated as macroscopic anomalies,and their space-time distribution was studied. The research indicates that in time distribution,the number of macroscopic anomalies peaked before the earthquake,and these peak values appeared twice after the earthquake. In space distribution,the distribution of macroscopic anomalies before the earthquake was the same as that after the earthquake. In this paper,the mechanism of occurrence of macroscopic anomalies and the role of macroscopic anomalies in forecasting earthquake were also discussed.展开更多
Macroscopic anomalies from"Earthquake Cases in China"are statistically analyzed in this paper. The conclusion is as follows: The probability of occurrence of macroscopic anomalies before earthquakes increase...Macroscopic anomalies from"Earthquake Cases in China"are statistically analyzed in this paper. The conclusion is as follows: The probability of occurrence of macroscopic anomalies before earthquakes increases with magnitude. The larger the earthquake magnitude, the more macroscopic anomalies appear. The temporal distribution of macroscopic anomalies is as follows: There are few macroscopic anomalies at beginning; as time goes on,the number of macroscopic anomalies increases; the increase of macroscopic anomaly quantity accelerates with the impending earthquake and reaches a climax when the earthquake breaks out. The spatial distribution pattern of macroscopic anomalies is as follows: macroscopic anomalies appear at the epicenter at the beginning,then spread out,and finally arise explosively at the epicenter area.展开更多
基金sponsored by the National Basic Research Program (973 Program),China (2008CB425700)
文摘The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan M_S 8. 0 earthquake is less than that of the Menglian earthquake. The number of anomalies and stations associated with the Wenchuan earthquake increased in the early stage of the short-term range,as opposed to the later period for the Menglian and Lijiang earthquakes. Most of the medium term anomalies occurred two to three years before the Wenchuan earthquake,when the number of anomaly stations and items was eleven,and a great change appeared in the observation values in about half of the stations ( items ) . However,for the Menglian earthquake,medium term anomalies happened one to two years before the earthquake, the number of abnormal stations and items reached 20,and a sharp change appeared in the observation values six months to one year before the earthquake in about 30 percent of the stations or items. In the epicenter and the nearby area,the macroscopic abnormalities started 3 years before the Wenchuan earthquake and lasted intermittently until 1 month before the earthquake. Within 2 percent of the total area of the province,the macroscopic abnormalities accounted for 30 to 50 percent of the total number of anomalies of the Province. For the Xingtai,Tangshan,Haicheng,Songpan earthquakes,the macroscopic anomalies started two to three months before,or on the very day of the earthquakes. The common feature of the precursors between the Wenchuan and other strong earthquakes is the appearance of tremendous changes in a certain number of observation values of anomalies in the mid and short terms before all these earthquakes.
基金sponsored by the National KeyTechnology R&D Program (2006BAC01B03-04-04)
文摘The macroscopic anomalies before and after the May 12,2008 Wenchuan M8. 0 earthquake were collected and analyzed in this paper. The credible anomalies occurring from February 1 to June 10,2008 were treated as macroscopic anomalies,and their space-time distribution was studied. The research indicates that in time distribution,the number of macroscopic anomalies peaked before the earthquake,and these peak values appeared twice after the earthquake. In space distribution,the distribution of macroscopic anomalies before the earthquake was the same as that after the earthquake. In this paper,the mechanism of occurrence of macroscopic anomalies and the role of macroscopic anomalies in forecasting earthquake were also discussed.
基金This project was sponsored by the National Science&Technology Pillar Program of China(2012BAK19B04-05)"Monitoring,Prediction and Research"Three Combinations Subject of China Eanthquake Administration(151503)
文摘Macroscopic anomalies from"Earthquake Cases in China"are statistically analyzed in this paper. The conclusion is as follows: The probability of occurrence of macroscopic anomalies before earthquakes increases with magnitude. The larger the earthquake magnitude, the more macroscopic anomalies appear. The temporal distribution of macroscopic anomalies is as follows: There are few macroscopic anomalies at beginning; as time goes on,the number of macroscopic anomalies increases; the increase of macroscopic anomaly quantity accelerates with the impending earthquake and reaches a climax when the earthquake breaks out. The spatial distribution pattern of macroscopic anomalies is as follows: macroscopic anomalies appear at the epicenter at the beginning,then spread out,and finally arise explosively at the epicenter area.
