NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Age constraints for the present fault configuration in the Imperial Valley, California: Evidence for northwestward propagation of the Gulf of California rift systemReleveling and other geophysical data for the Imperial Valley of southern California suggest the northern section of the Imperial-Brawley fault system, which includes the Mesquite Basin and Brawley Seismic Zone, is much younger than the 4 to 5 million year age of the valley itself. A minimum age of 3000 years is calculated for the northern segment of the Imperial fault from correlations between surface topography and geodetically observed seismic/interseismic vertical movements. Calculations of a maximum age of 80,000 years is based upon displacements in the crystalline basement along the Imperial fault, inferred from seismic refraction surveys. This young age supports recent interpretations of heat flow measurements, which also suggest that the current patterns of seismicity and faults in the Imperial Valley are not long lived. The current fault geometry and basement morphology suggest northwestward growth of the Imperial fault and migration of the Brawley Seismic Zone. It is suggested that this migration is a manifestation of the propagation of the Gulf of California rift system into the North American continent.
Document ID
19900012177
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Larsen, Shawn (California Inst. of Tech. Pasadena., United States)
Reilinger, Robert (Massachusetts Inst. of Tech. Cambridge., United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1990
Subject Category
Geophysics
Report/Patent Number
NAS 1.26:186541
NASA-CR-186541
Accession Number
90N21493
Funding Number(s)
CONTRACT_GRANT: NAG5-814
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available