The 7.2-magnitude earthquake that shook Southern California and northern Baja on Sunday is of great interest to UCSB seismologists, who are collecting information from a nearby research station. The earthquake was the largest in the Southern California region since 1992.
Two deaths were reported and an unknown number of people were injured in the quake, which struck at 3:40 p.m. Sunday in Guadalupe Victoria, about 108 miles east of Tijuana.
Scientists at UCSB will supply the information they are gathering to engineers for use in earthquake planning of buildings and city infrastructures.
The Easter quake occurred near one of several research stations used for gathering earthquake data. The site is called the Wildlife Liquefaction Array and is run as part of the George E. Brown Jr. Network for Earthquake Engineering Simulation program of the National Science Foundation, through the Institute for Crustal Studies at UCSB.
“This is a great data set that will validate all the effort that has been put into these arrays,” said Ralph Archuleta, chairman of UCSB’s Earth Science Department.
The Wildlife site is in an area susceptible to liquefaction, which occurs when the saturated layer of sand below the surface “liquefies” during the strong shaking of an earthquake. In order to monitor the process of liquefaction, the Wildlife site has several instruments that record variations in the pressure of the groundwater located in these saturated layers.
Jamison Steidl, a UCSB seismologist and principal investigator, left Santa Barbara on Tuesday to deploy more sensors at the Wildlife station just north of the Mexican border.
“This is an exciting and unique data set, showing the process of excess pore pressure generation that leads to the liquefaction of soils, which can cause significant damage to the built environment,” Steidl said. “It is through this type of data that scientists will be able to better predict liquefaction during earthquakes, and engineers will be able to better mitigate the damaging effects.”
Steidl said Sunday’s quake did not reach the point of liquefaction. He also noted that, because of the aftershocks, there is a possibility of another large earthquake being generated through a variety of fault lines in the area.
According to the U.S. Geological Survey, the epicenter of Sunday’s earthquake is an area with a high level of historical seismicity.
The nees@UCSB group will present the data at a meeting of the Seismological Society of America from April 21- 23 in Portland, Ore.