Long-term measurement of strong-motion earthquakes offshore southern California.

摘要

This paper describes a new long-life Seafloor Earthquake Measurement System (SEMS) and presents earthquake data obtained from the seafloor near an offshore oil production field. The SEMS is a battery-powered (8 year life) digital data acquisition system which telemeters data via a sonar link. Seafloor earthquake data from SEMS indicate that the seafloor vertical acceleration is nearly an order of magnitude weaker than the corresponding on-shore vertical motions. The importance of the SEMS measurements in designing earthquake-resistant offshore structures is also described. 13 refs., 6 figs., 1 tab.