Bulletin of the Seismological Society of America
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Bulletin of the Seismological Society of America; February 1990; v. 80; no. 1; p. 57-68
© 1990 Seismological Society of America
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by SUSONG, D. D.
Right arrow Articles by BRUHN, R. L.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Structure of a fault segment boundary in the Lost River fault zone, Idaho, and possible effect on the 1983 Borah Peak earthquake rupture

DAVID D. SUSONG, SUSANNE U. JANECKE and RONALD L. BRUHN

DEPARTMENT OF GEOLOGY AND GEOPHYSICS UNIVERSITY OF UTAH, SALT LAKE CITY, UTAH 84112

Abstract

The 1983 Borah Peak earthquake (Ms 7.3) initiated within the southern part of the Thousand Springs segment in the Lost River fault zone, east-central Idaho. The earthquake rupture propagated unilaterally to the northwest over a distance of 36 km and was accompanied by sinistral-normal slip within the fault zone. At the surface, the southern-most part of the rupture zone is marked by a bend in the Lost River fault zone at the intersection between the Thousand Springs segment to the north and the Mackay segment of the fault zone to the southeast. The intersection between the two fault segments is a lens-shaped area that contains numerous NW- and NE-striking faults that cut the Paleozoic bedrock. Several of the faults within the intersection zone ruptured at the surface during the 1983 earthquake.

A three-dimensional geometrical model of the intersection zone between the Thousand Springs and Mackay fault segments was constructed from geological mapping in conjunction with previously published interpretations of geodetic and seismological data. The longitudinal axis of the intersection zone plunges to the southwest, where its projected position in the subsurface roughly coincides with the location of the 1983 earthquake's hypocenter at a depth of 15 to 16 km. The intersection zone between the two fault segments may have played a dual role during the Borah Peak earthquake, both marking the site of rupture nucleation, but also acting to arrest spread of the rupture to the southeast onto the adjacent Mackay segment.




This article has been cited by other articles:


Home page
 GeosphereHome page
C. J. Lewis, J. N. Gardner, E. S. Schultz-Fellenz, A. Lavine, S. L. Reneau, and S. Olig
Fault interaction and along-strike variation in throw in the Pajarito fault system, Rio Grande rift, New Mexico
Geosphere, June 1, 2009; 5(3): 252 - 269.
[Abstract] [Full Text] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
Stress Triggering of Conjugate Normal Faulting: Late Aftershocks of the 1983 Ms 7.3 Borah Peak, Idaho, Earthquake
Bulletin of the Seismological Society of America, June 1, 2004; 94(3): 828 - 844.


Home page
 Bulletin of the Seismological Society of AmericaHome page
D. B. Mason
Earthquake magnitude potential of the Intermountain Seismic Belt, USA, from surface-parameter scaling of late Quaternary faults
Bulletin of the Seismological Society of America, October 1, 1996; 86(5): 1487 - 1506.
[Abstract] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1990 by the Seismological Society of America.