When Strike-Slip Faults Bend

Text by L. Whalen

Models by P. Prince

 

Strike-slip faults often seem like the least complex faults out of the bunch compared to thrust and normal faults, but it turns out that there’s a lot more to be said (and modeled)!

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Figure from Cunningham and Mann (2007)

 

Strike-slip faults are where the crust is sliding past one another and can form linkages between areas experience convergence or divergence. Where strike-slip faults bend things get interesting as it creates zones of compression (called restraining bends) and tension (called releasing bends).

This video shows the development of a restraining and a releasing bend and then shows a cross-section of the model highlighting the different flower structures (for more information on flower structures see our previous post).

A real world example of where you can find  these structures is the fault system responsible for the Mw 7 earthquake that affected Haiti on January 12th, 2012.

 

haiti-outcrops-1
Zoomed out map of Haiti. For explanation of butterfly outcrop patterns see the video above.
haiti-2
Zoomed in map of Haiti. Note the butterfly pattern in pink.
Seismotectonics of southern Haiti: A new faulting model for the
A) Elevation map of Haiti. B) cross-section showing flower structure located on line A-A’. C) 3-D block diagram showing another view of the structure. Figure from Saint Fleur et al. (2015). 
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