Post-seismic slip following the El Major earthquake.

Two creepmeters were installed at a depth of 35 cm in sand beneath the Yuha desert in the month following the 4 April earthquake. The instruments are both a few km north of the Mexican border.

The monuments consist of 1.5 m steel square section driven in to the dirt in the form of a buried tripod and bolted at their upper ends.

Data to Feb 2011

Calibrated slip data (dextral mm vs degrees C) may be downloaded as csv files suitable for reading directly into excel below.

Superstition Hills fault

Laguna Salada West Branch

Laguna Salada East Branch

 

Laguna Salada Faults

The El Major earthquake 4 April 2010 triggered slip on eleven faults in southern California, several of them previously unknown.

Creep-meters were installed after the earthquake on two branches of the Laguna Salada fault in the Yuha desert to monitor potential afterslip.

Data

The figure shows data from three creepmeters and a subsurface temperature gage in the Yuha Desert. The Laguna Salada East branch creepmeter was initially installed without a data logger but recorded less than 0.1 mm of slip April-August. The Laguna Salada west branch recorded triggered slip at the time of a nearby Mw5.7 aftershock, and has continued to slip slowly since (0.42 mm/yr). The creep rate on the Superstition Hills fault since the earthquake has been 0.6 mm/yr.