Ground Motion Simulations To Investigate The Feasibility Of Space-Based Seismometry

Abstract

This report describes elastic finite-difference simulations of ground motion resulting from explosions and earthquakes for use in a Laboratory Directed Research and Development Feasibility Study (LDRD-FS). The results will be used to as input into further simulations of various spaced-based remote-sensing techniques, such as laser ranging and radar systems. The ground motion calculations involve two types of sources: shallow fully-coupled explosions at relatively shallow depth (1 km) and strike-slip earthquakes at 5 km depth. The event sizes vary from M W 3.3 to 5.5 to capture a broad range of possible surface motion. The simulations are presented as densely sampled full-field images of ground velocity and displacement as well as peak ground motion versus distance from the event. The resulting peak displacements in the near source region (0-40 km) range from centimeters (10-2 m) for the largest events at short ranges to microns (10-6 m) for the smallest events at longer ranges. Peak velocities range from centimeters/second (10-2 m/s) to micron/second (10-6 m/s).