Magnitude Anomalies and Propagation of Local Phases
Abstract
The report describes a study of magnitude anomalies in French Polynesia. A first approach gives an anomaly per station which is roughly a function of azimuth valid for all French Polynesia plus a station's constant. A more detailed study shows the influence of local structure. Next, a theoretical study of generation and propagation of crustal seismic waves, radial and vertical displacement are computed up to 500 km for various sources (earthquakes and explosions). The last section discusses propagation of T waves and conversion into seismic waves at a continental slope level. We explain the rather long duration of T phases in continental station (some minutes, in French Polynesia only some 10 seconds) by conversion of water waves to seismic waves along a large area of the continental slope. This was verified experimentally. Seismic wave magnitude; Seismic data anomalies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 31, 1983
- Accession Number
- ADA217195
Entities
People
- B. Massinon
- M. Bouchon
- N. Ravalau
- P. Mechler
- Y. Cansi