The method of radiation energy （ER） of the earthquake wave measured by the peak velocity （r·v） of the ground motion is applied to a detailed study on the temporal and spatial distribution of the seismic appar...The method of radiation energy （ER） of the earthquake wave measured by the peak velocity （r·v） of the ground motion is applied to a detailed study on the temporal and spatial distribution of the seismic apparent stresses （σa） for the moderate and small earthquakes and two aftershock sequences in Yunnan area. The results show that there exists an obvious non-homogeneity for the seismic apparent stresses in the spatial distribution. The concentrated regions of the high apparent stresses are related to the active places of the moderate and small earthquakes. Before the Dayao M=6.2 earthquake, there was a period in which the apparent stresses were high and the value was 5 times of the average value, 0.25 MPa. The relatively high values of apparent stresses distribute around the epicentral area of the major shock and nearby. It indicates that the variation characteristics of the apparent stresses can be taken as a new kind of criterion for the earthquake-risk forecast. Usually the ratio of the apparent stresses of the aftershock sequence σaA to the ones σaM of main shock is less than 1.0.展开更多
There has been protracted historical evidence of a relative paucity in the distribution frequency of global earthquakes within the M = 3.5 to 4.0 range. We observed a similar phenomenon for all recently recorded earth...There has been protracted historical evidence of a relative paucity in the distribution frequency of global earthquakes within the M = 3.5 to 4.0 range. We observed a similar phenomenon for all recently recorded earthquakes from January 2009 through August 2013. Frequency distributions with increments of M = 0.1 verified the trough of the diminished incidence to be between M = 3.6 and 3.7 with an abrupt increase between M = 3.9 and 4.0. The calculated equivalent photon wavelength for the energies associated with M = 3.6 approaches Planck’s Length while the related time increment is the cutoff frequency for the Zero Point Fluctuation force coupled to gravity. The conspicuous congruence between Planck’s time and length and the lower than expected frequency based upon Gaussian assumptions of distribution for the discrete band of energy associated with this magnitude range of earthquakes suggests a conduit may exist between intrinsic features of Planck space-time and geophysical processes. The existence of such a connection would encourage alternative explanations for sun-seismic activities as due to solar instabilities. Instead, it may reflect influence upon both from alterations in the structure of space being traversed by the solar system as it moves through the galaxy.展开更多
By the aftershock frequency estimation method based on the calculation of coseismic static Coulomb stress changes and rate-and state-dependent fault constitutive law,we calculate the frequency of "direct "af...By the aftershock frequency estimation method based on the calculation of coseismic static Coulomb stress changes and rate-and state-dependent fault constitutive law,we calculate the frequency of "direct "aftershocks of the Wenchuan earthquake related to coseismic static Coulomb stress changes in its aftershock zone and the areas nearby.It shows that the frequency is significantly lower than the truth in the main rupture zone,especially in the southern rupture zone,due to the decrease of stress level on the rupture plane of the main shock resulting from coseismic Coulomb stress change.The study also shows that the effect of the Coulomb stress change on the duration of aftershock activity is associated with the lower limit magnitude.The duration is about 15-16 months for aftershocks above ML4.0,and close to 60 months for aftershocks above ML3.5.In this period,the ratio of the"direct"aftershocks caused by coseismic Coulomb stress change ranges between 44.7% to48.6%,which suggests that,even in the "effective"period of coseismic Coulomb stress changes,about half of the aftershocks on the main shock rupture plane are independent of coseismic Coulomb stress changes.It is pointed out that those aftershocks may be related to the afterslip or the viscoelastic relaxation,which are time dependent cases.展开更多
基金Key project of Science and Technology from Yunnan Province (NG2001).
文摘The method of radiation energy （ER） of the earthquake wave measured by the peak velocity （r·v） of the ground motion is applied to a detailed study on the temporal and spatial distribution of the seismic apparent stresses （σa） for the moderate and small earthquakes and two aftershock sequences in Yunnan area. The results show that there exists an obvious non-homogeneity for the seismic apparent stresses in the spatial distribution. The concentrated regions of the high apparent stresses are related to the active places of the moderate and small earthquakes. Before the Dayao M=6.2 earthquake, there was a period in which the apparent stresses were high and the value was 5 times of the average value, 0.25 MPa. The relatively high values of apparent stresses distribute around the epicentral area of the major shock and nearby. It indicates that the variation characteristics of the apparent stresses can be taken as a new kind of criterion for the earthquake-risk forecast. Usually the ratio of the apparent stresses of the aftershock sequence σaA to the ones σaM of main shock is less than 1.0.
文摘There has been protracted historical evidence of a relative paucity in the distribution frequency of global earthquakes within the M = 3.5 to 4.0 range. We observed a similar phenomenon for all recently recorded earthquakes from January 2009 through August 2013. Frequency distributions with increments of M = 0.1 verified the trough of the diminished incidence to be between M = 3.6 and 3.7 with an abrupt increase between M = 3.9 and 4.0. The calculated equivalent photon wavelength for the energies associated with M = 3.6 approaches Planck’s Length while the related time increment is the cutoff frequency for the Zero Point Fluctuation force coupled to gravity. The conspicuous congruence between Planck’s time and length and the lower than expected frequency based upon Gaussian assumptions of distribution for the discrete band of energy associated with this magnitude range of earthquakes suggests a conduit may exist between intrinsic features of Planck space-time and geophysical processes. The existence of such a connection would encourage alternative explanations for sun-seismic activities as due to solar instabilities. Instead, it may reflect influence upon both from alterations in the structure of space being traversed by the solar system as it moves through the galaxy.
基金funded by the special project of the National Science&Technology Pillar Program during the Twelfth "Five-year Plan" Period(2012BAK19B02-05-02)
文摘By the aftershock frequency estimation method based on the calculation of coseismic static Coulomb stress changes and rate-and state-dependent fault constitutive law,we calculate the frequency of "direct "aftershocks of the Wenchuan earthquake related to coseismic static Coulomb stress changes in its aftershock zone and the areas nearby.It shows that the frequency is significantly lower than the truth in the main rupture zone,especially in the southern rupture zone,due to the decrease of stress level on the rupture plane of the main shock resulting from coseismic Coulomb stress change.The study also shows that the effect of the Coulomb stress change on the duration of aftershock activity is associated with the lower limit magnitude.The duration is about 15-16 months for aftershocks above ML4.0,and close to 60 months for aftershocks above ML3.5.In this period,the ratio of the"direct"aftershocks caused by coseismic Coulomb stress change ranges between 44.7% to48.6%,which suggests that,even in the "effective"period of coseismic Coulomb stress changes,about half of the aftershocks on the main shock rupture plane are independent of coseismic Coulomb stress changes.It is pointed out that those aftershocks may be related to the afterslip or the viscoelastic relaxation,which are time dependent cases.
