Earthquake Clustering Precise Positioning. Teleseismic Information - Tangshan Earthquake Sequence Application

Tangshan earthquake caused the most loss in China from 20 century. The Characteristics, complexity and cause of formation are reviewed. Using a new earthquake location program, developed by E. R. Engdahl and E. A. Bergman, the earthquake sequences of Tangshan region from July 26, 1976 to April 14, 1998 are relocated. Comparing the results with the ones by other multiple-events location programs reported, it has many advantages in both efficient use of available information and computational speed. The integrality of ISC earthquake catalog is test by Rydelek-Sacks method.The main achievements and improvements of the earthquake sequences are reviewed. Some problems in it are discussed. Various approaches to seismic location are discussed. The basic theories, characteristics and applications of each are approach summarized and compared.