Historical Seismograms and Earthquakes of the World

From the standpoint of the seismologist studying actual waveforms (as opposed to travel times) a new era began in 1963 with the establishment of the World‐Wide Standardized Seismograph Network (WWSSN): Well‐calibrated seismograms from all over the world were available from a single data distributor. But the life of this network has been brief compared to the repeat times of great earthquakes; to learn about many of these, we must turn to pre‐WWSSN seismograms, which extend back to the start of instrumental seismology around 1900. These seismograms, now termed historical seismograms, are a primary subject of this book, a collection of papers derived from a 1985 International Association of Seismologists and Physicists of the Earth's Interior symposium. These older seismograms often contain detailed waveform data that could not be used when they were made but which can now be modeled to determine earthquake source parameters. Papers by H. Kanamori, by S. K. Singh, and by S. Stein, E. Okal, and D. Wiens review this area; Kanamori's paper has an especially valuable discussion of instrument responses and a useful list of large earthquakes, while Stein et al. show the contibution older data can make to understanding areas of low seismicity. Even seismograms of lower quality can be of value, as K. Abe shows by deriving magnitudes and origin times of Chinese and California earthquakes from 1898 through 1912 using recordings made by undamped seismometers.