El Salvador is located in Central America at the axis of geographical coordinates 14° north latitude and 89° west longitude. Situated inside the circumpacific "ring of fire" it is thus vulnerable to sudden earthquakes and volcanic eruptions.
Since 1520, El Salvador has sustained approximately 40 destructive earthquakes, an average of one earthquake every 11.4 years. The interval of time between earthquakes during the centuries, however, has been variable. For instance, given the importance of San Salvador as a city since the beginning of the 16th century, it shows historically that over any 100-year interval, there have been four catastrophic earthquakes in the region. During the 20th century, there have been already three large earthquakes in the region. During the 20th century, there have been already three large earthquakes in 1917, 1919, and 1965. If a recurrence of four earthquakes per century is a valid premise, then one may expect another large destructive earthquake before the end of this century.
In the following sections, a summary of the seismological programs in El Salvador, their present status, and programs proprosed for the future are discussed.
