Geophysical Surveys of Bear Lake, Utah-Idaho, September, 2002

The objectives of the September, 2002 Geophysical Surveys of Bear Lake, Utah-Idaho operations, preliminarily reported here, were (1) to compile a detailed bathymetric map of the lake using swath-mapping techniques, in order to provide baseline data for a variety of applications and studies, and (2) to complete a sidescan-sonar survey of the lake, providing a nearly complete acoustic image of the lake floor. Limited amounts of subbottom acoustic-reflection data (chirp) were also collected, along with samples of lake-floor sediments representative of different kinds of backscatter patterns.

These surveys followed an earlier subbottom acoustic-reflection survey (1997), using boomer and 3.5 kHz systems (S. M. Colman, unpublished data). Past seismic-reflection work has indicated that faults secondary to the east-side master fault cut the lake floor. These faults were among the primary targets of the sidescan-sonar survey.