The San Jacinto fault in Moreno Valley could cause an earthquake at any time that would affect the Riverside and San Bernardino area. However, one Cal State Long Beach professor hopes his research will reduce the damaging effects.
Nate Onderdonk, assistant professor in the Department of Geological Sciences, has been studying the fault for the past five years.
Onderdonk’s work focuses on learning how fast the fault is slipping, or how fast the sides move relative to each other. He also studies the history of the fault to better understand how much time lapses between each major earthquake.
“The main point of my research is to get a better idea of what kind of earthquake hazard the fault poses for Southern California,” Onderdonk said. “In this case, what we found is that the fault seems to have a big earthquake about every 160-200 years. The last big earthquake on that fault was a little over 200 years ago, so we think the fault is due for a big earthquake.”
The data collected is put into a fault assessment model for California and will aid city planners and architects to better design buildings, roads and bridges.
Onderdonk works with a team including graduate students and professors from San Diego State and Cal State San Bernardino. The graduate students gain valuable experience working in the field.
“It really gives them experience in doing fault hazard studies, which many geology majors end up doing as a job,” Onderdonk said about working in the field. “There’s a lot of demand for geologists; almost all our students have a job lined up by the time they leave.”
Graduate student Scott Kenyon worked with Onderdonk last summer to log one of the trenches in the San Jacinto fault. He took carbon-14 samples from the layers of the trench and defined separate layers to make a digital rendering of the trench walls.
“This fault is important to understand because it is thought to accommodate 25-40 percent of the San Andreas Fault which accommodates 80 percent of the North Pacific plate motion,” Kenyon said. “Essentially what Dr. Onderdonk and others learn from their research on this and other faults will go into modeling the fault and help to assess the associated hazards.”
The work Onderdonk and his team conducts also comes up during his lectures at CSULB. He teaches Intro Geology and Natural Disasters, and takes his classes to the San Jacinto fault to give them examples of what they learn in class.
“I want people to realize that these faults are a hazard for Southern California and something you have to learn to live with, just like wildfires or flooding,” Onderdonk said. “They only have big earthquakes infrequently, so it’s easy to forget.”
He continued to mention the positive effects of earthquakes.
“Those big faults and earthquakes are what create the mountains and the landscape — everything that makes California such a nice place to live,” he said. “All our mountains are formed along faults. Without the faults you would not have those mountains.”
Onderdonk’s interest in geology began as he was finishing his bachelor’s in Physics from Principia College in Illinois.
He earned his master’s and Ph.D. in geology from UC Santa Barbara, did postdoctoral research at the University of Oslo, Norway, and studied in Greenland.
“I couldn’t believe that people got paid to do this kind of work outside,” Onderdonk said. “Once I learned what geologists do, like travel a lot and work outside, that kind of got me hooked.”
In addition to his work on the San Jacinto fault, Onderdonk is involved in a number of projects in Southern California and abroad.
He works in Santa Barbara dealing with pieces of crust that have broken off of the Pacific Plate, mud volcanoes by the Salton Sea, and in the Arctic Island of Spitsbergen, North of Norway.
Disclaimer: The Daily 49er is not responsible for Postings made on www.daily49er.wpengine.com. Persons commenting are solely responsible for Postings made on this website. Persons commenting agree to the Terms of Use of the website. If Postings do not abide by the Rules of Conduct or Posting Regulations as listed in the Postings Policy, the Daily 49er has all rights to delete Postings as it deems necessary. The Daily 49er strongly advises individuals to not abuse their First Amendment rights, and to avoid language suggestive of hate speech. This site also encourages users to make Postings relevant to the article or other Postings.