Seismic Anisotropy in the Crust at the Mid-Atlantic Plate Boundary in South-West Iceland

Publication Status is "Submitted" Or "In Press: 
LDEO Publication: 
Publication Type: 
Year of Publication: 
1994
Editor: 
Journal Title: 
Geophysical Journal International
Journal Date: 
Dec
Place Published: 
Tertiary Title: 
Volume: 
119
Issue: 
3
Pages: 
783-790
Section / Start page: 
Publisher: 
ISBN Number: 
0956-540X
ISSN Number: 
Edition: 
Short Title: 
Accession Number: 
ISI:A1994PW39800010
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Call Number: 
Abstract: 

Seismograms of microearthquakes recorded on stations of the SIL network in south-western Iceland exhibit strong shear-wave splitting, and are consistent with being caused by aligned parallel cracks in the uppermost crust. Splitting times of 0.1-0.3 s are observed, with the larger values (0.2-0.3 s) occurring beneath stations in the highly lineated Western Volcanic Zone, and the smaller values (0.1 s) in the younger, less fractured South Iceland Seismic Zone. Five of the stations have a fast shear-wave polarization azimuth of N30 degrees E-N40 degrees E, parallel to the axis of the Western Volcanic Zone (i.e. the Mid-Atlantic Ridge in Iceland) and in the direction of maximum horizontal compression defined by fault, dyke and fissure strikes and microearthquake focal mechanisms. Station GYG, in the north-western part of the network, has the significantly different azimuth of N70 degrees E. This is parallel to one of the local strike-slip fault trends, and is probably due to a lineated rock fabric caused by those faults.

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Pw398Times Cited:26Cited References Count:27

DOI: