First off let me say that I studied the earth imaging aspect of seismology. I wouldn't consider myself an expert in earthquakes, though I do love the subject. Maybe I am compared to a layperson, but not compared to a PhD that studies earthquakes.
That said, the Gigafactory's earthquake risk is significant. Here's a map of faults that have moved in the last 15,000 years.
View attachment 196415
The factory is less than five miles from the
Olinghouse fault zone (the red lines) which produced an estimated 6.7 magnitude earthquake in 1869. However, the USGS estimates the recurrence interval as 8,000-16,000 years so another event on that stretch of the fault doesn't seem likely.
The
Pyramid Lake fault zone (the orange north-northwest trending lines at the top of the map) appears to have quakes every 1,500 years or so, with the
last event probably being a magnitude 7 - 7.3 around 1850.
In 1954,
two earthquakes (7.3 and 6.9) occurred four minutes apart, located 67 miles to the east in Dixie Valley. That's about the same distance as San Francisco from the epicenter of the 1989 Loma Prieta earthquake. It's another slow-moving fault zone, so repeat events appear to occur only every 3,400 - 50,000 years.
So the area is seismically active. It seems there's a pretty good chance the factory will experience an earthquake during its lifetime, though I'm sure it's adequately designed to handle anything mother earth is capable of throwing at it. While these could be major earthquakes, they'd still be rather small compared to the devastating quakes that will eventually happen on the San Andreas or in the Pacific Northwest.
If you want to look at the faults in more detail in Google Earth, here are the
kmz files from the USGS.
This is probably more info than you wanted, but like I said, I love the subject
I don't believe the Great Basin is as seismically active as the plate boundaries. The processes that turned Nevada into a landscape looking like a rumpled carpet (and raised up the plateau in northern Arizona and New Mexico) is still happening to some extent, but it's not as active now as it was a few million years ago.
Big earthquakes are much more common along plate boundaries, especially very active ones. The Pacific plate is moving in a northwesterly direction (it used to move due north, but shifted direction right about the time India crashed into Asia 42 million years ago). The San Andreas fault is part of this plate boundary and moves in the direction of the Pacific Plate. You can tell the direction of the plate movement from the angle of the Hawaiian Islands as well as the angle of the San Andreas fault.
The Juan de Fuca plate is a small plate that has been mostly subducted below the NA Plate. It stretches from a line drawn due west of Mt Lassen in California on up to British Columbia. It used to stretch all the way down the coast to Panama, but the center section was completely subducted and turned into the side slip plate boundary of the San Andreas fault. The southern section of the once big plate is called the Cocos plate off Mexico and is responsible for the volcanoes in Mexico and Central American.
There is a tradition in Geology that the founder of anything new can name it anything they want, as long as they don't name it after themselves. The Coco's plate is named after the girlfriend of its founder.
Because the Pacific plate is putting pressure on the Juan de Fuca plate obliquely, the Juan de Fuca plate is only getting squeezed hard in the south along the boundary between the Juan de Fuca plate and the side slip San Andreas fault. That's where the 1700 earthquake was and where most of the quakes from the subduction zone happen.
The west coast of the US is not generally at risk for tsunamis. They are most devastating in shallow waters and the west coast is also the continental shelf, so the water gets deep very fast off the coast. That is not the case in places that got plastered by the Boxing Day earthquake and tsunami. The east coast of the US and the Caribbean are very shallow waters and would be at risk for devastating tsunamis if one came their way.
Harbors and rivers are still at risk for tsunami surges. Along the southern Oregon coast some boats were sunk in harbors by the tsunami caused by the 2011 earthquake in Japan. My father also saw the tsumani's effect in Morro Bay, CA. He said it was like a very fast moving tide. Sort of like watching the tide come in and go out in about an hour.
A big tsunami hitting the Straits of Juan de Fuca would cause a lot of coastal flooding around Puget Sound and a tsunami up the Columbia River might cause a small surge as far upstream as Vancouver, but the population centers of the Northwest as generally safe from major tsunami damage. The epicenter of a subduction zone quake would also be a fair distance from the population centers, both Portland and Seattle are a ways inland from the subduction zone.
The Oregon coast has more communities than the Washington coast. A good portion of the Pacific coast in Washington is national park. Those communities are most at risk from damage. They are 50 miles closer to the epicenter than the larger cities and their harbors are at risk from tsunami damage.
Unfortunately Japan might get nailed the worst by a Juan de Fuca subduction zone earthquake. We know the exact date of the 1700 earthquake (about 9PM Jan 26, 1700) because Japan got nailed with a tsunami afterwards and Japanese records have a tsunami happening without anyone feeling an earthquake.
Anyway, I'm not too concerned about Tesla suffering any major setbacks from an earthquake either in Fremont or Nevada. They will happen someday, but the nature of quakes is such that if you take the necessary precautions, there is still a chance that something freaky will happen with just the wrong shaking and the building will collapse, but most building prepared for earthquakes survive intact.
A lot of large buildings built in earthquake zones have structures to allow the building to roll with the quake. I was on the 12th floor of a skyscraper in downtown Seattle in the 2001 earthquake. The building had giant rollers in the basement that rolled back and forth and the entire building just swayed back and forth. It was a little tough walking in the building after the quake because the building kept oscillating for a while and you couldn't see it, you'd just run into walls as you walked because the building was moving under you.
I expect the GF has some features like that built into its design. It's also a steel framed building and steel flexes well.
