Accession Number:

ADA626034

Title:

Software Development: Digitizing Historical Analog Seismograms for Wave Climate Analyses

Descriptive Note:

Annual rept.

Corporate Author:

SCRIPPS INST OF OCEANOGRAPHY LA JOLLA CA INTEGRATIVE OCEANOGRAPHY DIV

Personal Author(s):

Report Date:

2001-09-30

Pagination or Media Count:

7.0

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.

Subject Categories:

  • Meteorology
  • Physical and Dynamic Oceanography
  • Seismology
  • Computer Programming and Software

Distribution Statement:

APPROVED FOR PUBLIC RELEASE