The first device designed to measure earthquake-induced ground motion was built in A.D. 132 by Chang Heng in China, and for the next sixteen centuries, studies of earthquakes remained the exclusive domain of seismologists. Not until the latter part of the eighteenth century, when French nobleman Deodat Gratet de Dolomieu reported the first significant field observations of effects from the 1783 earthquake in southern Italy, did geology begin to play a role in earthquake studies. Systematic geological studies of earthquakes and faults did not begin for more than 100 years later in the latter part of the 19th century, when seminal reports such as those by G. K. Gilbert emphasized the connection between surficial features and earthquakes. More than two hundred years have passed since Dolomieu's pioneering descriptions, but only during the past 20 or 30 years has the unique value of earthquake geology been widely recognized and appreciated. The ...