213 research outputs found
A method for estimating the origin time of an ensuing mainshock by observations of preshock crustal seismic deformation
Observations on accelerating crustal deformation due to the generation of intermediate magnitude preshocks in the Aegean area are used to propose a method for prediction of the origin time of an ensuing mainshock. The method is based on a precursory seismic excitation that occurs in the preshock region at a time correlated to the origin time of the oncoming mainshock. The uncertainty in this prediction is of the order of ± 1.5 years with relatively high confidence ('90%)
Foreshock and aftershock sequences of the Cremasta earthquake and their relation to the waterloading of the Cremasta artificial lake
Investigation of the time and magnitude distributionof the fore- and aftershocks of the Cremasta lake earthquake which occurredon February 5, 1966 is made. The deformation characteristics andspatial distribution of these shocks is also studied. Strong evidence is presentedthat the foreshocks and the main shock have been triggered by thewaterloading of the Cremasta artificial lake
GLOBAL RELATIONS BETWEEN SEISMIC FAULT PARAMETERS AND MOMENT MAGNITUDE OF EARTHQUAKES
ABSTRACT The most reliable of the globally available relative data have been used to derive empirical formulas which relate the subsurface fault length, L, the fault area, S, and fault width, w, with the moment magnitude, M. Separate such formulas have been derived for earthquakes generated by strike-slip faulting, by dip-slip faulting in continental regions and by dip-slip faulting in lithospheric subduction regions. The formula which relates the fault area with the magnitude is combined with the definition formulas of seismic moment and moment magnitude to derive also relations between the fault slip, u, and the moment magnitude for each of the three seismotectonic regimes. For a certain magnitude, the fault length is larger for strike-slip faults than for dip-slip faults, while the fault width is small for strike-slip faults, larger for dip-slip faults in continental regions and much larger for dip-slip faults in regions of lithospheric subduction. For a certain magnitude, fault slip is about the same for strike-slip faults and dip-slip faults in continental regions and smaller for dip-slip faults in regions of lithospheric subduction
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