Method for Determination of Impending Earthquake Focal Parameters Based on Daylight Surface Displacement Data

摘要

The fast development of a network of permanent stations as well as the enhancement of capabilities and resolution of portable GPS receivers facilitates the accumulation of information on earth's surface displacement and opens up new possibilities for modeling geodynamic processes based on geodesic data.rnThe arrows in Fig. 1 indicate the mean annual displacement of GPS stations in the south of the West Siberia over the period of 2000-2003 relative to the Novosibirsk Station prior to the earthquake of September 27, 2003 [1]. Based on these data, major deformations of contraction (black lines) and extension (gray lines) were estimated by means of triangulation. The results revealed an increase of almost an order of magnitude, as compared to the background level, in local deformation in the vicinity of the epicenter of the impeding seismic event. This was interpreted as a preparation for the earthquake and used as a basis for the following quantitative determination of focal parameters.