On the strength of oceanic fracture zones and their influence on the intraplate stress field

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JB01076· OSTI ID:6822673

Bergman, E A; Solomon, S C ^[1]

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1. MIT, Cambridge, MA (United States)

We use the locations and source mechanisms of oceanic intraplate earthquakes to test the hypothesis that the strength of oceanic fracture zones is less than that of normal oceanic lithosphere. The 77 earthquakes selected for the study have well-determined focal mechanisms and epicenters in regions where fracture zones are well mapped. We have search for dependence of faulting style, fault orientation, or principal stress direction on the distance from the nearest fracture zone. If fracture zones were generally weaker than the surrounding lithosphere, one of the principal horizontal stresses would be oriented nearly perpendicular to the fracture zone; we find no evidence that principal stresses near fracture zones are oriented preferentially in this manner. There is a slight tendency for earthquakes to occur near fracture zones, and patterns of fault orientation and sense of slip support the view that differential cooling and horizontal contraction on fracture zones may contribute seismogenic stress. 56 refs.

• OSTI ID: 6822673
• Journal Information: Journal of Geophysical Research; (United States), Vol. 97; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
GEOLOGIC FAULTS
STRESS ANALYSIS
OCEANIC CRUST
FRACTURE MECHANICS
STRESSES
DISTRIBUTION
EARTHQUAKES
PLATE TECTONICS
EARTH CRUST
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
MECHANICS
SEISMIC EVENTS
TECTONICS
540210* - Environment
Terrestrial- Basic Studies- (1990-)
580000 - Geosciences