Seismicity and contemporary tectonics of the Hebgen Lake-Yellowstone Park Region

Journal Article · Mon Feb 10 04:00:00 EST 1975 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB080i005p00733· OSTI ID:6851425

Trimble, A B; Smith, R B

Detailed seismic monitoring of the Hebgen Lake-western Yellowstone Park region of Wyoming and Montana has delineated a zone of earthquakes extending 80 km in a direction N80/sup 0/W from the northwest edge of the Yellowstone calderas to the Madison Valley. The active zone includes the epicentral area of the 1959 Hebgen Lake earthquake (magnitude 7.1). Focal depths ranged from near surface to 15 km in the Hebgen lake region, whereas near the caldera boundaries the maximum focal depths decreased to 5 km. The abrupt change to shallow focal depths over and near the calderas may be related to increased temperature and pore pressure sufficient to inhibit brittle fracture. Six composite and four single-event fault plane solutions indicate north-south regional extension. Three composite fault plane solutions for earthquakes along the northwest boundary of the Yellowstone calderas indicate northwest-southwest crustal shortening, possibly from uplift on concentric fractures around the calderas.

• OSTI ID: 6851425
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 80:5; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
DATA
DEPTH
DIMENSIONS
EARTHQUAKE FOCI
EXPERIMENTAL DATA
GEOLOGIC FAULTS
GEOLOGIC STRUCTURES
GRAPHS
INFORMATION
MONTANA
NORTH AMERICA
NUMERICAL DATA
PUBLIC LANDS
ROCKY MOUNTAIN REGION
SEISMICITY
TECTONICS
USA
WYOMING
YELLOWSTONE NATIONAL PARK