Software Development: Digitizing Historical Analog Seismograms for Wave Climate Analyses
Abstract
The severe winter storm cycle along the California coast during the 1997-98 El Nino-Southern Oscillation (ENSO) focused attention on the variability, and recent apparent intensification, of the wave climate along the West Coast. Few instrumental wave records exist before systematic buoy measurements began in the early 1980 s. The number of large storm events reported by Seymour (1996) for 1982-83 ENSO is conspicuously greater than earlier strong ENSO s during the 1940- 41 and 1957-58 winters (produced from hindcasts using meteorological data). This suggests that either the effect of strong ENSO s on the wave climate of California has significantly changed, or the wave-climate record prior to 1980 is seriously deficient. Accurate estimates of theWest Coast wave climate can be obtained by inversion of the double-frequency microseism spectrum from broadband seismometer data (Bromirski et al., 1999b). Analyses of NOAA buoy data indicate that the wave climate is very similar along much of the California coast (Bromirski et al., 1999a and 1999b), implying that reconstructed wave measurements from the San Francisco Bay area using seismic data from Berkeley, CA can be extrapolated to the Eel River coastal region, a study area for the ONR sponsored STRATAFORM program. Analog paper seismograms archived at UC Berkeley from 1930-1980 can be used to reconstruct the historical wave record.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2001
- Accession Number
- ADA626034
Entities
People
- P. D. Bromirski