This study investigates the relation between the Coulomb failure stress of the mainshock with the aftershocks sequence following the 2018 Palu-Donggala earthquake in Indonesia.We calculate the Coulomb failure stress u...This study investigates the relation between the Coulomb failure stress of the mainshock with the aftershocks sequence following the 2018 Palu-Donggala earthquake in Indonesia.We calculate the Coulomb failure stress using the available coseismic fault models,which had varied moment magnitudes between M_W7.53~M_W7.62.Different interpretations of the fault sources were suggested by previous studies.While two fault models suggested that one inland fault segment ruptured during the earthquake,another fault model proposed that two fault segments ruptured inland of Central Sulawesi and along the coast of Palu bay.We further overlay the positive and negative values of Coulomb failure stress with the reported relocated aftershock.We find that only by conducting Coulomb failure stress analysis,we can not favour the preference of the coseismic fault which explains aftershock distribution.This investigation demonstrates that additional observational data from geological field surveys are required to identify the surface rupture in comparison with the coseismic fault model.展开更多
The long time practice of observational research on earthquake prediction has shown that the information on shortterm and imminent earthquake precursors can hardly be detected, but it is very important for practical ...The long time practice of observational research on earthquake prediction has shown that the information on shortterm and imminent earthquake precursors can hardly be detected, but it is very important for practical and effective earthquake prediction. The result of analysis and study in this paper has shown that the anomaly of quasi static atmospheric electric field may be a kind of reliable information on short term and imminent earthquake precursors.On such a basis, the 20 years′ continuous and reliable data of atmospheric electric field observed at the Baijiatuan seismic station are used to study the correlation between the anomalies in seismic activity and relative quiet periods bear on the occurrence of near earthquakes within 200 km range around Beijing after the Tangshan earthquake. The observational results recently reported before hand in written form and earthquakes that actually occurred in near field in corresponding time periods are compared and analyzed. The efficacy of these written prediction opinions about near earthquakes in the recent 10 years is tested. From the test results, the brilliant prospect that the anomaly of quasi static atmospheric electric field may really become a reliable mark for making short term and imminent earthquake predictions is discussed. Besides, as a preliminary step, some judgment indexes for predicting earthquakes by use of the observational data of atmospheric electric field before earthquakes are put forward. In the last part, it is pointed out that it would be possible to obtain more believable judgment indexes for determining the three elements of near earthquakes before greater earthquakes ( M S5) only if a relatively reasonable station network (2～4 stations every 10 000 km 2) is deployed and further investigation is made.展开更多
基金supported by the 2019 World Class University Research Fund of Bandung Institute of Technology for International Research No.LPPM.PN-10-30-2019the 2018 Overseas Research Grants of the Asahi Glass Foundation No.FTTM.PN-5-01-2019
文摘This study investigates the relation between the Coulomb failure stress of the mainshock with the aftershocks sequence following the 2018 Palu-Donggala earthquake in Indonesia.We calculate the Coulomb failure stress using the available coseismic fault models,which had varied moment magnitudes between M_W7.53~M_W7.62.Different interpretations of the fault sources were suggested by previous studies.While two fault models suggested that one inland fault segment ruptured during the earthquake,another fault model proposed that two fault segments ruptured inland of Central Sulawesi and along the coast of Palu bay.We further overlay the positive and negative values of Coulomb failure stress with the reported relocated aftershock.We find that only by conducting Coulomb failure stress analysis,we can not favour the preference of the coseismic fault which explains aftershock distribution.This investigation demonstrates that additional observational data from geological field surveys are required to identify the surface rupture in comparison with the coseismic fault model.
文摘The long time practice of observational research on earthquake prediction has shown that the information on shortterm and imminent earthquake precursors can hardly be detected, but it is very important for practical and effective earthquake prediction. The result of analysis and study in this paper has shown that the anomaly of quasi static atmospheric electric field may be a kind of reliable information on short term and imminent earthquake precursors.On such a basis, the 20 years′ continuous and reliable data of atmospheric electric field observed at the Baijiatuan seismic station are used to study the correlation between the anomalies in seismic activity and relative quiet periods bear on the occurrence of near earthquakes within 200 km range around Beijing after the Tangshan earthquake. The observational results recently reported before hand in written form and earthquakes that actually occurred in near field in corresponding time periods are compared and analyzed. The efficacy of these written prediction opinions about near earthquakes in the recent 10 years is tested. From the test results, the brilliant prospect that the anomaly of quasi static atmospheric electric field may really become a reliable mark for making short term and imminent earthquake predictions is discussed. Besides, as a preliminary step, some judgment indexes for predicting earthquakes by use of the observational data of atmospheric electric field before earthquakes are put forward. In the last part, it is pointed out that it would be possible to obtain more believable judgment indexes for determining the three elements of near earthquakes before greater earthquakes ( M S5) only if a relatively reasonable station network (2～4 stations every 10 000 km 2) is deployed and further investigation is made.
