Carson City Aftershocks Continue after Magnitude 4.5 Earthquake: College of Science Seismological Lab Tracks Seismic Activity in Silver State
by Mike Wolterbeek, Nevada Today, Research & Innovation, March 26, 2020
Speaker: Stephen Dickenson, Adjunct Research Faculty, Nevada Seismological Laboratory, UNR
Topic: Post-Earthquake Forensic Investigations of Soil-Structure Interaction: A Sleuth’s Guide to Seismological, Geological, and Geotechnical Clues
Abstract: This presentation will focus on lessons learned from field observations and forensic evaluations of building foundations made by Dr. Dickenson and his colleagues at sites in Wellington, New Zealand following the 2016 Mw 7.8 Kaikoura Earthquake. An overview will be provided that addresses seismological aspects of the strong ground motions recorded at the project sites and the significant impact of local geology on the strength of the ground shaking. This overview will lead into the case study of seismic performance of a five-story, pile-supported building, which was built in 2009, well instrumented with accelerometers, and had been subjected to two prior Mw 6.5 earthquakes. The project team was charged with evaluating the likelihood of significant damage to the pile foundations; a forensic investigation that required thorough seismological, geological, and geotechnical evaluation.
Biography: Stephen Dickenson is the President of New Albion Geotechnical, Inc., a consultancy specializing in geotechnical earthquake engineering applications for major civil works. Dr. Dickenson’s consulting, research, and post-earthquake reconnaissance efforts have primarily focused on dynamic soil-structure-interaction and the seismic performance of slopes and earth structures, earth retention systems, bridges, port and coastal facilities, and buildings. He has led, and supported, numerous investigations of the seismic performance of civil infrastructure involving development on weak soils, deep foundations and buried utilities subjected to ground failure, and the effectiveness of ground treatment for mitigating hazards.
Dr. Dickenson earned his Bachelor’s degree in Geology from the University of California, Berkeley, his Master’s Degree in Civil Engineering from Virginia Tech, and his Doctorate in Civil Engineering from the University of California, Berkeley. He is a licensed Civil Engineer (CA, NV, OR, WA) and board-certified Diplomate in Port Engineering (ACOPNE D. PE) with over 30 years of experience in consulting practice, academia, applied research, and development of continuing education for geo-professionals. He has resided in numerous places along a circuitous path from the San Francisco Bay Area to the Pacific Northwest, and now makes his home in Reno where he enjoys all of the outdoor time he can get.
LOCATION: SURESTAY PLUS HOTEL BY BEST WESTERN, 1981 TERMINAL WAY, RENO, NEVADA 89502
SOCIAL HOUR: 5:15PM
RSVP TO MERRILY GRAHAM NO LATER THAN 5:00 PM, TUESDAY, MARCH 10TH:
This month we will be serving corned beef, salad, and key lime pie. On the RSVP, please indicate if you have a dietary restriction such as vegan, vegetarian or gluten free options.
Finding Faults—How the Burgeoning Walker Lane May Split the American West
By Mike Wolterbeek, Nevada Today, February 18, 2020
Excerpts: “California won’t fall into the ocean, but it could get nudged hundreds of miles offshore, making Nevada the new coastline of the continent, scientists at the Nevada Bureau of Mines and Geology at the University of Nevada, Reno hypothesize. They have combined decades of data and the latest technology to study the Walker Lane, an approximately 1000-kilometer-long (625 miles) corridor riddled with hundreds of earthquake faults.
Several researchers at the University are part of a group of scientists who are studying the massive system of relatively discontinuous faults that runs through western Nevada. It is known as the Walker Lane and in about 7-8 million years or so could become the new tectonic boundary between the North American and Pacific plates. The group at the University is relatively rare, as it includes expertise that analyzes fault zones at three different time scales from tens of millions of years (structural geology/tectonics) to the past approximately two million years (paleoseismology) to the present (geodesy). This combination of expertise is needed to understand the evolution of something potentially as grand as the Walker Lane. In essence, the University team combines the most modern fieldwork techniques with the latest technologies such as satellites, LIDAR and computer simulations…”
“But it’s the combination of three science disciplines that illustrates the prominence of the Walker Lane – paleoseismology, geodesy and Faulds’ specialty of structural geology/tectonics. All three perspectives are crucial in analyzing something like the Walker Lane, because they provide three different timeframes with which to evaluate the evolution of the Walker Lane – from what’s happening now, to the past million years or so, and to the long-term (back-tracking tens of millions of years). We have all three disciplines in the College of Science at the University of Nevada, Reno…”
The NBMG research team described in this story includes Jim Faulds, Rich Koehler, Jayne Bormann, Bill Hammond, Corné Kreemer, Geoffrey Blewitt, Seth Dee, Chris Henry, and students Colin Chupik and Conni De Masi.
“Millions of people worldwide will practice how to Drop, Cover, and Hold On at 10:17 a.m. on October 17 during Great ShakeOut Earthquake Drills!
Nevadans can join them today by registering for the 2019 Great Nevada ShakeOut. Participating is a great way for your family or organization to be prepared to survive and recover quickly from big earthquakes—wherever you live, work, or travel.”
By Rong-Gong Lin II, Staff Writer, Los Angeles Times
August. 6, 2019 6 AM
Excerpts are copied below. You can read the complete story here: Nevada’s First Recorded Earthquake Death? This Could Be It, Caused by Ridgecrest Temblors
“For all the power of the Ridgecrest earthquakes — the strongest with an epicenter in Southern California in nearly two decades — the only death related to the temblors may have actually occurred outside the state.
The death in Nevada is illustrative of the significant earthquake risk the Silver State, though not as bad as California, still endures. The Reno area, for instance, has a seismic risk that approaches that of the San Francisco Bay Area, according to Nevada state geologists…
There has never been a documented death from an earthquake in Nevada, according to Craig dePolo, earthquake geologist at the state Bureau of Mines and Geology, who has exhaustively researched records of the 23 earthquakes with epicenters in Nevada of magnitude 6 or greater. “If indeed Mr. Ray’s death was caused by an earthquake, it would be the first time it’s been recorded,” he said…
Nevada has been largely quiet of destructive earthquakes since the 1960s, except for the magnitude 6 Wells earthquake of 2008, which caused an abandoned two-story building to collapse and two more buildings to partially collapse, and damaged about 30 others. Officials reported $19 million in damage.
But from the 1850s to the 1950s, there were 22 earthquakes of magnitude 6 or greater in Nevada.
“Up until about the 1960s, Nevada was very active,” dePolo said. “It used to be known as an earthquake state, just like California. But we’ve lost a lot of the folklore because there’s been fewer earthquakes. Awareness is moderate to low.”
Nevada is farther away from the main plate boundary dividing the Pacific and North American plates, but the state still gathers seismic strain over the decades that must be released in earthquakes eventually. “The handle is turning, and the box is there — it’s just a matter of time before the jack-in-the-box pops out.”
The Reno area has an earthquake risk approaching that of San Francisco, dePolo said; Las Vegas’ risk is less, but still exists. Faults in the basin Reno sits in is capable of generating earthquakes as big as magnitude 6.8; a larger fault in the Carson Valley just south of Reno could generate a quake as large as magnitude 7.4.
Just east of Las Vegas is Frenchman Mountain, and on the east side of the mountain lies an earthquake fault capable of producing an earthquake of possibly magnitude 6.7, dePolo said.”
By Daniel Rothberg, July 25th, 2019 – 2:00amIndy Environment: Water & Land
Read the full article here: Earthquakes, Yucca Mountain, and Why Everyone is Talking about the Walker Lane
The Indy Environment newsletter breaks down reporting on water, public land and development. Sign-up here to receive it in your inbox. For suggestions or tips, email email@example.com.
Nevada is turning into California. The latest: Earthquakes.
“Without scaring people, we should be quite concerned that we could have a fairly sizable earthquake,” said Jim Faulds, the director of the Nevada Bureau of Mines and Geology.
Two recent Southern California earthquakes shook furniture as far as Las Vegas and have raised questions about the risk of tremors in Nevada. Geologically speaking, the Great Basin is a maze of fault lines, and much of it is still unexplored. Although most associate California with deadly quakes, Nevada is the third most seismically active state (after California and Alaska).
As state geologist, Faulds has spent a lot of time thinking about this issue and was recently featured in a WIRED story that looked at a fault system that extends through Western Nevada.
It is known as Walker Lane.
Walker Lane, Faulds said, accounts for about 20 percent plate motion between the Pacific and North American plates — and it could one day become the main boundary between the plates. But compared to the well-known San Andreas Fault, Walker Lane is disorganized, with smaller faults that make it difficult to assess earthquake risk. What if more than one fault ruptures at once? According to Faulds, there are more questions like that and more research needs to be done.
And there is a Yucca Mountain angle.
The proposed nuclear waste repository sits on the eastern part of the fault system. Last week, Faulds and the director of the Nevada Seismological Lab, wrote to Gov. Steve Sisolak urging more surveying of the area with new technology like LiDAR and new geophysical tools.
“The Walker Lane needs more thorough analysis and Yucca Mountain does as well,” he said.
In general, Faulds said the greatest earthquake risk is in Western Nevada along this fault, but the geological survey is working on a risk assessment for Southern Nevada as well. There have also been tremors across the Great Basin, including the 2008 Wells quake. I’ll be writing more about earthquakes, the science behind them, and the unknowns. I’ll also look at what it means for Western Nevada.”
A series of earthquakes as recent as 1954 occurred in the Fallon area. These were similar in size to the earthquakes this month near Ridgecrest, California and serve as a reminder that Nevadans do live in earthquake country.
The text below includes excerpts from this publication:
Damaging Earthquakes in Nevada: 1840s to 2008, by Craig M. dePolo
The damaging earthquakes briefly described on this map occurred during the period from the mid-1800s to 2008. They are the largest historical examples, but do not include all significant and damaging earthquake events in the state. These events and their descriptions remind us that Nevada is earthquake country and that earthquakes will produce strong shaking within our communities in the future. A wise course of action for Nevadans is to heed the lessons of past events, know how to react to an earthquake, and actively prepare for earthquakes. Many ideas to stay safe and protect your property from earthquakes can be found in Living with Earthquakes in Nevada on the web at www.nbmg.unr.edu (NBMG Special Publication 27).
1954, July 6
Rainbow Mountain Earthquakes
M 6.2 and M 6.1
On July 6, 1954 at 3:13 a.m. PST an earthquake of “major proportions” struck near the town of Fallon. The magnitude 6.2 event (Pancha and others, 2006) was felt from San Francisco to Wendover and from southern Oregon to just north of Las Vegas (Cloud, 1956). Eight men were injured, one with a fractured leg, at the Fallon Naval Air Station when barracks lockers fell on them while they were sleeping in their bunks (FS 7/7/54). More than a dozen buildings and businesses were damaged in Fallon (FS 7/7/54; FS 8/11/54). Damage was most severe to brick and concrete buildings and included cracked and fallen walls and plaster. Many chimneys fell or were damaged. A dam broke, and there was extensive damage to the Newlands Project irrigation system (FS 7/7/54). President Eisenhower declared the Fallon region a disaster area and made available $200,000 of disaster relief funding (FS 7 /14/54). Earthquake surface rupturing from the July 6th event was more than 18 km (11 mi) long, and the ground was vertically offset by as much as 35 cm (-14 in; Tocher, 1956; Caskey and others, 2004). Extensive liquefaction occurred, accompanied by water spouts, ground settling, and the filling of irrigation canals with sediment (Steinbrugge and Moran, 1956). A magnitude 6.1 aftershock occurred on the afternoon of July 6, only 11 hours after the mainshock and extended the surface ruptures to the south (Caskey and others, 2004).
1954, August 23
The Stillwater earthquake struck the Fallon region on August 23, 1954 at 10:51 p.m. PST and was estimated to have been magnitude 6.8 (Pancha and others (2006). It created 53 km (33 mi) of surface faulting (Caskey and others, 2004). This was a right-lateral strike-slip earthquake with some normal offset, and the largest surface rupture had about 1 m (-3 ft) of right-lateral strike-slip offset (Caskey and others, 2004). In Fallon, seven buildings were damaged (FS 8/25/54; FS 9/1/54). Of these buildings, three, including a school building, were so severely damaged they had to be torn down. Chimneys were thrown down or cracked, windows were broken, and there was a lot of nonstructural damage (FS 8/25/54). A four-inch water main was broken in two places (FS 8/25/54). Again there was extensive liquefaction in the Fallon area (Murphy and Cloud, 1956). Unfortunately, a large part of the emergency remediation work conducted on the canal system was completely obliterated by the Stillwater earthquake (Murphy and Cloud, 1956).
1954, December 16
Fairview Peak–Dixie Valley Earthquakes
M 7.1 and M 6.9
On December 16, 1954 there were two large, back-to-back earthquakes east of the Fallon area that were felt throughout Nevada and created several large ground ruptures. The first event, the Fairview Peak earthquake, a right-normal-oblique-slip event, occurred at 3:07 a.m. PST and had a magnitude of 7.1 (Pancha and others, 2006). This was followed four minutes and 20 seconds later (3:11 a.m.) by a magnitude 6.9 event, the Dixie Valley earthquake, a normal-slip event (Slemmons and others, 1965). Both earthquakes created spectacular surface ruptures over a total area of 100 km (62 mi) long and 14.5 km (9 mi) wide, with ground offsets of as much as 3.8 m (12.5 ft) vertical and 2.9 m (9.5 ft) right lateral (Slemmons, 1957; Caskey and others, 1996). The earthquake was in a sparsely populated region, and there were no reported injuries and only minor building damage and content losses. In Dixie Valley, an “adobe cellar, gasoline tank and water tank, and stone wall collapsed”, a stove moved several feet, and a woman was thrown from her bed due to the shaking (Murphy and Cloud, 1956). In one living room, a piano “kangarooed” its way to the opposite side of the room during the shaking (FS 12/22/54). In the surrounding region, dishes broke, walls and chimneys were cracked in the towns of Austin, Luning, Mina, Rawhide, Fallon, Lovelock, Eureka, and Carson City (Murphy and Cloud, 1956). Damage in Carson City included cracked walls and fallen plaster in the Capitol building, the State Printing Building, and the State Prison (Murphy and Cloud, 1956). Water lines were broken at Lovelock, Mina and near Gabbs (Murphy and Cloud, 1956).