Because of the differential motions between the Northern and Southern Hemispheres of the Earth, there exists a motion discordant zone between them. On the surface this zone consists of 13 large faults dominant with st...Because of the differential motions between the Northern and Southern Hemispheres of the Earth, there exists a motion discordant zone between them. On the surface this zone consists of 13 large faults dominant with strike-slip. We call it a global shear zone at low-latitudes (E system). By statistical analysis of temporal distribution of earthquakes Mw≥7.5 in the E system and the circum-Pacific (P system) during 1900―2003, we find that there exist quasi-episodic and alternative activities in and between these two systems. This phenomenon is likely associated with the half-sphere oscillation in dilation and contraction and the change of the Earth’s rotation rate.展开更多
The tempo-spatial variation of seismic activity before great Chile Mw8.8 earthquake on February 27, 2010 is studied. Some results are as follows： ①Two types of seismic gaps appeared before the Chile MwS.8 shock. One...The tempo-spatial variation of seismic activity before great Chile Mw8.8 earthquake on February 27, 2010 is studied. Some results are as follows： ①Two types of seismic gaps appeared before the Chile MwS.8 shock. One is background gap of Mw≥8.0 earthquakes with 360 km length since 1900, the other is seismogenic gap formed by M≥5.5 earth- quakes with 780km length five years before the Chile earthquake; ②There was only one Mw7.1 earthquake in the middle and southern part of Chile from 1986 to 2010. The obvious quiescence of Mw≥7.0 earthquake is the long-term background anomaly for the Chile earthquake; ③ The quiescence of M≥6.5 earthquakes appeared in South American block and its vicinity during the period from 2007 to 2009, and the quietude state has been disappeared three months before the Chile Mw8.8 earthquake; ④ The deep and intermediate-depth earthquake activity has been noticeablely strengthened in the subduction zone of South American block since 1993; ⑤The great Chile earthquake shows that global seismicity is still in the active period of Mw≥8.5 earthquakes since 2004. Based on the characteristics of the former two active periods, several great earthquakes with Mw≥8.5 would take place in a few years. In addition, the circum-Pacific seismic belt would be the main region for Mw≥8.0 earthquakes.展开更多
文摘Because of the differential motions between the Northern and Southern Hemispheres of the Earth, there exists a motion discordant zone between them. On the surface this zone consists of 13 large faults dominant with strike-slip. We call it a global shear zone at low-latitudes (E system). By statistical analysis of temporal distribution of earthquakes Mw≥7.5 in the E system and the circum-Pacific (P system) during 1900―2003, we find that there exist quasi-episodic and alternative activities in and between these two systems. This phenomenon is likely associated with the half-sphere oscillation in dilation and contraction and the change of the Earth’s rotation rate.
文摘The tempo-spatial variation of seismic activity before great Chile Mw8.8 earthquake on February 27, 2010 is studied. Some results are as follows： ①Two types of seismic gaps appeared before the Chile MwS.8 shock. One is background gap of Mw≥8.0 earthquakes with 360 km length since 1900, the other is seismogenic gap formed by M≥5.5 earth- quakes with 780km length five years before the Chile earthquake; ②There was only one Mw7.1 earthquake in the middle and southern part of Chile from 1986 to 2010. The obvious quiescence of Mw≥7.0 earthquake is the long-term background anomaly for the Chile earthquake; ③ The quiescence of M≥6.5 earthquakes appeared in South American block and its vicinity during the period from 2007 to 2009, and the quietude state has been disappeared three months before the Chile Mw8.8 earthquake; ④ The deep and intermediate-depth earthquake activity has been noticeablely strengthened in the subduction zone of South American block since 1993; ⑤The great Chile earthquake shows that global seismicity is still in the active period of Mw≥8.5 earthquakes since 2004. Based on the characteristics of the former two active periods, several great earthquakes with Mw≥8.5 would take place in a few years. In addition, the circum-Pacific seismic belt would be the main region for Mw≥8.0 earthquakes.
