Nevada’s hidden earthquake risk revealed as Las Vegas, Reno shake
A recent series of earthquakes in Nevada served as a jarring reminder of the state’s seismic risk.
It all started with a devastating earthquake near Reno, followed by an even more disturbing tremor near Las Vegas. Neither earthquake caused significant damage, but left Nevada talking about the large geological forces that caused them.
Although California is known for its seismic activity, the danger doesn’t stop at the state border, experts say. There are many fault systems along the California-Nevada border, and one area scientists are concerned about is the Lake Tahoe Basin, according to Christie Rowe, director of the Nevada Seismology Laboratory.
“There are some major faults under the lake there,” he said. “They’ve had some pretty big earthquakes in the past.”
The largest earthquake to hit the Silver State in recent days occurred at 1:17 a.m. Friday, with a magnitude of 5.2, about 40 miles east of Reno. Just two days ago, a magnitude 4.4 rumble was heard in the desert about 60 miles north of Sin City, and some people reported that the tremor was weak.
The area east of Reno also experienced intense seismic activity in early April. According to media reports, the strongest of this series was a 5.7 magnitude earthquake 45 miles east of the city; this earthquake was strong enough to cause moderate to severe shaking in the small town of Silver Springs, causing items to fall off shelves and cabinets. No serious injuries or damage were reported in the earthquake that occurred on April 13.
The abundance of earthquakes is a reminder that earthquakes are actually a threat to Nevada; Of course, it is less profound than the seismic risk in California, but it is every bit as real.
Perhaps less well known is that Las Vegas is surrounded by faults on all sides; This may come as a surprise, as the city has never had a damaging earthquake in its short modern history.
But if and when someone attacks, the consequences can be dire. A magnitude 7 earthquake near Las Vegas could cause approximately $21 billion in damage and destroy vulnerable buildings and infrastructure. based on To Nevada Bureau of Mines and Geology.
Rowe said Incline Village, a town on the northeastern tip of Lake Tahoe, “closed a school when they discovered they were on the Incline fault, which is the magnitude 7 in geological history.”
The Tahoe Basin may see earthquakes this strong every few thousand years. scientists say. Earthquakes of this magnitude may even pose the risk of tsunami-like waves in the lake itself; Possible heights could exceed 30 feet and flood many areas near the coastline.
The last major tremor on the West Tahoe fault on the western shore of Lake Tahoe is capable of producing a magnitude 7.1 to 7.4 earthquake. The last major earthquake there was about 4,000 years ago.
Earthquakes can also produce landslides In the Tahoe Basin. A landslide that occurred about 50,000 years ago may have caused wave heights of more than 100 feet.
The danger of earthquakes causing landslides in lake areas is not only theoretical. In 1959, a magnitude 7.2 earthquake in Montana near Yellowstone National Park triggered the largest earthquake-triggered landslide in North America. 26 of the 28 people who died died as a result of the landslide overflowing the camping area. US Geological Survey.
Among the fault systems Rowe is particularly concerned about for Las Vegas are those west of the city: the Death Valley fault system and faults in neighboring valleys.
“We know these faults are magnitude 7,” Rowe said.
The Death Valley fault system is approximately 95 miles from Las Vegas. Another, the Hurricane fault system, is about 75 miles away, “in the northern corner of Arizona and into Utah,” according to Rowe.
The latter said it was “a pretty big mistake but it’s been pretty quiet lately.”
“There are also a few bugs in Las Vegas,” he added, but not much is known about them. Part of the problem is that many of the fine land formations that scientists need to examine to uncover evidence of past earthquakes have already been built.
Nevada lacks a key seismic safety tool found in California, Oregon and Washington; An earthquake early warning system run by the USGS that sends alerts to smartphones or computers before shaking begins.
Congress appropriated money for the USGS to implement this system in Nevada, but more funding is needed to establish the system in that state. Rowe said budget cuts and hiring freezes at the USGS have complicated efforts to expand the earthquake early warning system.
“How do you expand a program to a larger area when the agency running it is understaffed?” Rowe said.
Seismic sensors from Nevada are on hand to help alert Californians that a major Las Vegas earthquake has begun and that the impending tremor is seconds away.
“Ironically, if there was an earthquake in the Las Vegas area, the Californians who would be affected by it would be warned,” Rowe said. “But in Nevada, alerts wouldn’t be sent to us.”
Among the vulnerabilities Nevada has are unreinforced brick buildings, and there may be tens of thousands of them across the state. Brick buildings are among the deadliest structures in an earthquake; Walls collapsing outwards can kill people walking on the sidewalk and even crush cars and buses with lethal force.
A partially collapsed brick building in San Francisco crushed cars during the 6.9 magnitude Loma Prieta earthquake. Five people died when the fourth-floor wall of the brick building fell into the parking lot below.
(CE Meyer / US Geological Survey)
The recently earthquake-affected community of Silver Springs was built on an old lake bed that amplified the shaking from the quake, and there are many mobile homes there, according to Rowe.
In general, mobile homes are two to five times more vulnerable to an earthquake than wood-frame homes, according to earthquake experts in California.
“I’ve been getting a lot of calls from Silver Springs residents feeling aftershocks (even up to magnitude 3),” Rowe said. “So they’re talking about what appears to be constant shaking as we experience aftershocks right after the main shock.”
A woman said she was at home with her daughter during the earthquake.
“It was difficult to walk. I tried to hold him so that he could go under a table. It was difficult to move and maneuver, and we only heard the sound of falling items,” he said. KTVN-TV. The shaking was “really annoying” and strong enough to break his television.
Nevada has been largely spared from devastating earthquakes since the 1960s, except for magnitude 6 quakes 2008 Wells earthquakeIt caused the collapse of an abandoned two-story building and the partial collapse of two more buildings, and damaged approximately 30 more buildings in the northeastern part of the state. Authorities reported $19 million in damage.
However, from the 1850s to the 1950s, Nevada experienced 22 earthquakes of magnitude 6 or greater.
A magnitude 6.5 earthquake struck Nevada in 2020, but it was in a remote spot: about 200 miles northwest of Las Vegas and 125 miles southeast of Carson City. The Nevada Highway Patrol reported earthquake damage along a half-mile stretch of U.S. Highway 95 where large cracks appeared. Crews provided a temporary quick fix by shaving off the removed portion of the highway to reduce the bumps felt by drivers.
Even a magnitude 6 or 7 earthquake occurring far from a city can cause damage or death. The first documented earthquake-related death in Nevada occurred during one of two powerful Ridgecrest earthquakes in early July 2019, which shook parts of Southern California.
The body of 55-year-old Troy Ray was found on July 9, 2019; He was apparently working under his Jeep in his hometown of Pahrump, Nev., about 150 kilometers northeast of the epicenter, when his vehicle was believed to have crashed on top of him.
So are the recent earthquakes in Nevada a sign to worry?
In fact, they are “basically normal for Nevada earthquakes,” Rowe said. And “These Nevada earthquakes change nothing in terms of California’s earthquake risk.”
Still, major earthquakes can occur without notice, and that’s part of the risk of living in places like California and Nevada.
Rowe said people should participate in earthquake drills like ShakeOut, scheduled for Oct. 15, which reminds people what to do if they feel shaken by an earthquake: Fall, hide and hold on.
“School kids will do it at 10:15,” Rowe said, “but everyone should do it.”
