This paper describes the National Geodetic Survey (NGS) process for selecting and validating models for two recent earthquakes prior to their inclusion in the Horizontal Time Dependent Positioning software (HTDP v 2.9), the 28 September 2004 Parkfield, California earthquake with a magnitude of 6.0 and the 22 December 2003 San Simeon, California earthquake with a magnitude of 6.5 . The process o...

A new homogenous earthquake catalogue covering Bulgaria and the surrounding Balkan area has been created with intention of performing a consistent seismic hazard assessment across the region. In keeping with modern requirements of cataloguing seismicity, this catalogue has been made homogenous as far as possible with regards to magnitude, which has been provided on any of four different reporte...

We investigate the sequence of great earthquakes over the past century. To examine whether the earthquake record includes temporal clustering, we identify aftershocks and remove those from the record. We focus on the recurrence time, defined as the time between two consecutive earthquakes. We study the variance in the recurrence time and the maximal recurrence time. Using these quantities, we c...