Seismograms are now available from a large number of stations throughout the world for three large or destructive earthquakes in 1974. These are the earthquakes in the People's Republic of China (May 10, M 6.8), northern Peru (October 3, M 7.6), and the Leeward Islands (October 8, M 7.5).
Under the provisions of the Guide to International Data Exchange Through the World Data Centers, Seismology, seismograms have been collected and copied from a worldwide network of participating stations. There are records on hand for at least one of these earthquakes from 142 stations in 46 countries, including 37 received from WDC-B in the USSR and many from the worldwide standardized seismograph and Canadian networks. Many of the stations have sent records from three long-period and three short-period components.