The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration...The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration of strong earthquakes has mostly focused on finding the phenomena. Some attempts on getting regularity were comparatively subjective. This paper suggests that there should be indices of migration in earthquake dataset and the indexes should have statistical meaning if there is regularity in the migration of strong earthquakes. In this study, three derivative attributes of migration, i.e., migration orientation, migration distance and migration time interval, were statistically analyzed. Results in the North China region show that the migration of strong earthquakes has statistical meaning. There is a dominant migration orientation (W by S to E by N), a dominant distance (≤100km and on the confines of 300～700km), and a dominant time interval (≤1a and on the confines of 3～4a). The results also show that the migration will differ slightly with different magnitude range or earthquake activity phase.展开更多
13 earthquakes with M≥5.0 have been recorded in the northeast region of China since1970,among which eight medium-strong earthquakes are independent in space and time.Studies of seismicity before these eight medium-st...13 earthquakes with M≥5.0 have been recorded in the northeast region of China since1970,among which eight medium-strong earthquakes are independent in space and time.Studies of seismicity before these eight medium-strong earthquakes show that small earthquake activity was enhanced before the occurrences.Though seismicity increase is a common phenomenon in the northeast China region,we have difficulty in predicting the medium-strong earthquakes by this phenomenon alone.In order to predict medium-strong earthquakes through seismicity increase,this paper tries to propose a new method that calculates small earthquake frequency through the changing pattern of small earthquake activities based on the characteristics of small earthquake activity in the northeast China region.The results show that we can get the obvious anomaly frequency of small earthquakes before medium-strong earthquakes through the new method,and can obtain a medium to short term anomaly index for the northeast China region.展开更多
Illustration All the data in this catalog are chosen from the Preliminary Seismological Report of ChineseSeismic Stations (abbreviated to Monthly Report).The catalog includes the events of M≥4.7 inand near China and ...Illustration All the data in this catalog are chosen from the Preliminary Seismological Report of ChineseSeismic Stations (abbreviated to Monthly Report).The catalog includes the events of M≥4.7 inand near China and M≥6 all over the world.The Monthly Report is monthly complied by theNinth Section of Institute of Geophysics,CSB.展开更多
文摘The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration of strong earthquakes has mostly focused on finding the phenomena. Some attempts on getting regularity were comparatively subjective. This paper suggests that there should be indices of migration in earthquake dataset and the indexes should have statistical meaning if there is regularity in the migration of strong earthquakes. In this study, three derivative attributes of migration, i.e., migration orientation, migration distance and migration time interval, were statistically analyzed. Results in the North China region show that the migration of strong earthquakes has statistical meaning. There is a dominant migration orientation (W by S to E by N), a dominant distance (≤100km and on the confines of 300～700km), and a dominant time interval (≤1a and on the confines of 3～4a). The results also show that the migration will differ slightly with different magnitude range or earthquake activity phase.
基金sponsored by the 2013 Annual Earthquake Monitory,Forecasting and Research in Seismic Stations Fund,CEA
文摘13 earthquakes with M≥5.0 have been recorded in the northeast region of China since1970,among which eight medium-strong earthquakes are independent in space and time.Studies of seismicity before these eight medium-strong earthquakes show that small earthquake activity was enhanced before the occurrences.Though seismicity increase is a common phenomenon in the northeast China region,we have difficulty in predicting the medium-strong earthquakes by this phenomenon alone.In order to predict medium-strong earthquakes through seismicity increase,this paper tries to propose a new method that calculates small earthquake frequency through the changing pattern of small earthquake activities based on the characteristics of small earthquake activity in the northeast China region.The results show that we can get the obvious anomaly frequency of small earthquakes before medium-strong earthquakes through the new method,and can obtain a medium to short term anomaly index for the northeast China region.
文摘Illustration All the data in this catalog are chosen from the Preliminary Seismological Report of ChineseSeismic Stations (abbreviated to Monthly Report).The catalog includes the events of M≥4.7 inand near China and M≥6 all over the world.The Monthly Report is monthly complied by theNinth Section of Institute of Geophysics,CSB.
