Software Development: Digitizing Historical Analog Seismograms for Wave Climate Analyses

摘要

North Pacific storm systems strongly affect the California coast, with long period waves representing the single largest source of energy driving coastal processes. The understanding and modeling of near shore sediment transport over time requires a long record of wave statistics. The instrumental buoy wave record along the West Coast begins in the mid-1970's. The wave record along the California coast from 1930 to the beginning of the instrumental record can be obtained from analog long-period seismograms archived at UC Berkeley. Quantitative estimates of wave energy and climate change from archived seismograms require digital data for spectral processing. New software (SeisDig) has been developed for the efficient digitization of day-long seismograms for climatological studies. SeisDig is a Matlab based graphical user interface interactive digitizing package that produces digitized data from electronically scanned 'tif' images for wave climate reconstructions in Seismic Analysis Code (SAC2000) format.