Structural Damage, Ground Failure, and Hydrologic Effects of the Magnitude (Mw) 5.9 Draney Peak, Idaho, Earthquake of February 3, 1994

Abstract

INTRODUCTION A magnitude ( Mw ) 5.9 earthquake occurred at 09:05 (GMT) at 42° 44.42′ N. and 111° 8.93′ W. (Arabasz et al. , 1994) in the mountains of southeastern Idaho near the Idaho-Wyoming border, 100 km ESE of Pocatello, Idaho, and 18 km W of Afton, Wyoming (Figure 1). The earthquake, which was located near the center of the active part of the 1500-km-long Intermountain Seismic Belt, was preceded by foreshocks as large as M 4.7 (Nava et al. , 1994), and had an estimated focal depth of 8 km (U.S. Geological Survey, 1994). The main shock was felt in the immediate area and was reported felt by residents as far west as Pocatello, Idaho, and as far south as Moab, Utah, and Grand Junction, Colorado (Figure 2). Only minor damage, such as broken glassware, cracked plaster, and minor structural damage were reported by residents of Afton and the immediate epicentral area...