Locating Deep Earthquakes in Complex 3-D Velocity Structure Using a Modified Double-Difference Location Method
JIANG Guo-ming
ZHAO Da-peng
ZHANG Gui-bin
Abstract：The double-difference (DD) earthquake location algorithm cannot be used to locate earthquakes in the complex 3-D velocity models because it adopts a 1-D ray tracing technique and the Cartesian coordinates. In this study, we have improved the DD location method by adopting a 3-D ray tracing method and the spherical coordinates, and thus extended the range of its applications. To testify the feasibility and the precision of this new method, we have relocated the deep earthquakes that occurred beneath the Japan Sea, and analyzed the effect of velocity models by comparing the relocation results in four kinds of 3-D velocity models. Our results show that the improved DD location method is less affected by the velocity model, and the closer the velocity structure in the hypocenter to the real one is, the higher the location precision is. The improved DD location technique would be very useful for studying the mantle structure by using data from deep earthquakes.
Keywords：earthquakesdouble-difference location3-D velocity modelJapan Sea.
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 1001-1011 )