Open AccessStudy of the properties of seismicity in the Mexico region
Author(s) -
Prozorov A. G.,
Sabina F. J.
Publication year - 1984
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1984.tb05049.x
Subject(s) - induced seismicity , geology , aftershock , seismology , magnitude (astronomy) , earthquake swarm , physics , astronomy
Summary. New statistics of seismic properties are investigated in space and time for the Mexico region. They are main events seismicity (number of earthquakes with aftershocks excluded), swarming property, average magnitude (another way to study the slope of the recurrence time law), maximum magnitude, average focal depth and comparative efficiency of earthquakes in surface and body waves generation, known as creepex . Quite a number of anomalies of the spatial distributions of the statistics were found. Some of them have evident geophysical meaning, the explanation of others is rather controversial, and some others have no interpretation as yet. The most interesting phenomena are as follows: (1) The average focal depth distribution indicates a different trend for the Benioff zone west of approximately 96°W longitude, due north which fits the position of the Neovolcanic belt. (2) Creepex clearly distinguishes different tectonic areas, i.e. subduction zones (with low values), transform faults (medium) and ridges (high). (3) High swarming is related to places with young sedimentary geology. The time pattern of those properties, in places of strong earthquakes, is quite consistent and includes a phase of concentration of stress indicated by quiescence in average and maximum magnitude and main events seismicity, and also more efficient body wave generation and anomalous swarming. This phase is followed by an apparent weakening of the material indicated by a igher efficiency in surface wave generation.