Direct observation

As long as the medieval belief persisted that earthquakes were a punishment imposed upon man by God in retribution for sin, there was no reason to suspect that any one region should be more subject to earthquakes than another. After all, to err is human; and, consequently, sin must be universal. As worldwide communications improved, however, it became apparent either that the people of certain areas had fallen further from grace than others or that some other explanation for earthquakes was necessary.

Before the invention of the telegraph in 1840, news traveled slowly, and knowledge of even serious natural disasters often was not widely disseminated. The earliest extant compendium of seismicity is a list of 91 earthquakes between 34 and 1687 a.d., prepared by D. Vincenzo Magnati and first published in 1688 (Heck and Davis, 1946). There seems to have been no systematic attempt to gather information on the occurrence of earthquakes until Karl Ernst Adolf von Hoff began publishing annual lists of worldwide earthquakes in 1826 (Davison, 1927). Local lists had been prepared previously. For example, Zachary Grey in England published a pamphlet describing 61 earthquakes in 1750. Elie Bertrand's 1757 memoir on Swiss earthquakes included a list of 155 shocks. Domenico Pignataro listed 1186 shocks in Italy for the period of 1783–6; and Francisco Antonia Grimaldi in 1784 published a list of Calabrian earthquakes for the period 1181–1756. Louis Cotte in 1807 prepared a catalog of earthquakes of northern Europe.