Great Nevada Earthquake of 1915 spurs reminder for 2015 Great Nevada Shakeout

About 100 years ago Nevada was rocked by the largest earthquake in its history, the 1915 magnitude 7.3 Pleasant Valley earthquake south of Winnemucca. Only a few large earthquakes since then have rumbled the state, but nothing near the surface scar — with a vertical offset as high as 19 feet – that stretched 35 miles across Nevada’s Great Basin.

“The centennial mark, Oct. 2, of our biggest quake is a good opportunity to remind ourselves Nevada is earthquake country, and we should be prepared,” Graham Kent, director of the University’s Nevada Seismological Laboratory, said. “That 1915 earthquake is a grim reminder of what could happen now, anywhere in Nevada, and with a population base much higher and much more dense in our major cities.”

And what better way to stay prepared than the Great Nevada ShakeOut. It is a simple, coordinated “drop, cover and hold on” exercise to be held Thursday, Oct. 15 at 10:15 a.m. Last year more than 570,000 Nevadans participated. More than 568,000 Nevadans already are registered to participate this year in the annual statewide public earthquake drill. To register as an individual, business, school or government agency or organization, go to the official website www.shakeout.org/nevada. All Nevada residents are encouraged to register and participate.

"We get three magnitude 7 earthquakes about every century," Kent said. “It's been about 60 years since one of those has happened.”

Twenty-three earthquakes of magnitude 6 or greater have occurred in Nevada since 1857. There have been several earthquake swarms of note lately, and the Wells earthquake in 2007 that caused damage, however, residents have not seen the devastation a 7-plus event could cause.

“There’s less than a month to go; would be great to get another 50,000 people registered for the ShakeOut by Oct. 15,” Kent said. “Nevada has the third highest incidence of large earthquakes in the United States. A major earthquake in any community, north or south, is possible. We can’t prevent an earthquake, so we have to be resilient, to be prepared so we can perhaps lessen the impacts on lives and economic destruction that a major earthquake can cause.”

Participants of the drill are instructed to drop, cover, and hold on at 10:15 a.m. on Oct. 15 as if there were a major earthquake occurring at that very moment, and to stay in that position for at least 60 seconds – which is about the time it takes to register for the earthquake drill.

“We have schools participating from all parts of Nevada, mostly entire school districts, plus the University of Nevada, Reno and University of Nevada, Las Vegas,” Kent said. “That’s a lot of students. Now we’re focusing on getting their parents and their employers – whether private or government – to register and participate. Everyone in Nevada needs to have a plan and practice for an earthquake.”

Participants are also encouraged to practice other aspects of emergency plans and to “secure your space,” which includes retrofitting buildings to reduce damage and securing things within a building to prevent injury.

Craig dePolo, an earthquake geologist in the University of Nevada, Reno’s College of Science’s Nevada Bureau of Mines and Geology said, “Nevadans need to take this large earthquake to heart. Earthquakes are not abstract concepts that can be ignored. The Pleasant Valley earthquake caused damage to multiple communities that were as far as 50 miles away,” dePolo said. “This illustrates that large earthquakes cause widespread damage and can affect many communities at the same time.”

A webpage with comprehensive information about the Great 1915 Nevada Earthquake has been created with reports, links and photos following the earthquake. DePolo is spearheading a field trip to the Pleasant Valley earthquake site Saturday, Oct. 3.

Described by dePolo as a “great chance to see the geological impacts caused by a large earthquake,” the trip will start with a short overview talk in Winnemucca followed by a vehicle caravan with two stops in the earthquake area. The trip will be limited to the first 80 people who sign up. A guide book will be available on the 1915 earthquake centennial web page for those interested in making the trip on their own: www.unr.edu/centennial.

For more information and to sign up for the Great Nevada ShakeOut, visit www.ShakeOut.org/nevada.

Photo information: Cracks developed from the magnitude 7.3 1915 Pleasant Valley earthquake in alluvial soil near Lovelock. The disturbed area appears to have moved to the left relative to the background​. Photograph by Carl Stoddard.

— Mike Wolterbeek is a Communications Officer for the University of Nevada, Reno. He can be reached at mwolterbeek@unr.edu