Preface: Introduction and historical perspective

The construction of nuclear power plants, large dams, and other critical facilities in the United States and Europe during the 1970s led to a requirement that the sites for these structures be evaluated for seismic hazards. A necessary new approach to the evaluation of seismic hazards included the study of active faults, which led to the recognition in fault zones of earthquakes that pre-dated a written historical record. Paleoseismology, the study of ancient earthquakes based on their geological expression, became a primary tool in the siting and evaluation of critical facilities. However, virtually all of these studies were site-specific, without a broader understanding of the significance of active-fault features in the study of earthquakes. There seemed to be a barrier between the study of faults by the structural field geologist and the analysis of faulting in real time, which includes geomorphic expression of surface rupture accompanying earthquakes, and the study of how faulting is part of the natural evolution of landscapes, despite early attempts to do this by Charles Lyell (1875).

Analysis of active faults built on the work of nineteenth-century pioneers, including Charles Lyell of England (as part of his Principles of Geology), G.K. Gilbert of the United States (Owens Valley and San Andreas faults, California, and Wasatch fault, Utah), Alexander McKay of New Zealand (Hope fault), José Aguilera of México (faulting accompanying the 1887 Sonoran earthquake), and Bunjiro Koto of Japan (faulting accompanying the 1891 Mino-Owari earthquake).