Skip to main content
U.S. flag

An official website of the United States government

Slab tears and intermediate-depth seismicity

August 1, 2013

Active tectonic regions where plate boundaries transition from subduction to strike slip can take several forms, such as triple junctions, acute, and obtuse corners. Well-documented slab tears that are associated with high rates of intermediate-depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. Seismicity at each of these locations occurs, at times, in the form of swarms or clusters, and various authors have proposed that each marks an active locus of tear propagation. The swarms and clusters start at the top of the slab below the asthenospheric wedge and extend 30–60 km vertically downward within the slab. We propose that these swarms and clusters are generated by fluid-related embrittlement of mantle rocks. Focal mechanisms of these swarms generally fit the shear motion that is thought to be associated with the tearing process.

Citation Information

Publication Year 2013
Title Slab tears and intermediate-depth seismicity
DOI 10.1002/grl.50830
Authors Hallie E. Meighan, Uri S. ten Brink, Jay Pulliam
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Index ID 70176403
Record Source USGS Publications Warehouse
USGS Organization Woods Hole Coastal and Marine Science Center