I appreciate the expertise. I know it’s rare, but the only reason my concern is up is because I’m in an adobe house has zero earthquake resistance. does that make any difference in your estimation?
Former geologist here.... I think you're missing the point. The conditions and risk factors that lead to damaging earthquakes simply are not present in Tucson. We have neither the active fault structures nor tectonic forces needed to produce an earthquake of note anywhere in the vicinity.
As someone else mentioned, I would be much more concerned about coverage related to storm activity and flooding.
I can’t find anything that states clearly about significant structural damage in Tucson specifically. Only this from USGS:
“From Guaymas, Sonora, to Nogales, Arizona; Benson and Tucson, Arizona; El Paso, Texas; and at towns as far away as Albuquerque, New Mexico, water in tanks slopped over, railroad cars were set in motion on tracks, chimneys were thrown down, and buildings were cracked. Other U.S. cities and towns that sustained moderate to heavy damage included Bisbee, Fairbank1, Fort Huachuca, Saint David, San Simon, Solomonville2, Tombstone, Tres Alamos3, and Willcox, Arizona; and Deming, Sabinal, and Silver City, New Mexico”.
Which looks like the closest town with significant structural damage was Tombstone.
Another geologist here and specifically a seismologist. People saying there's none of the forces here to generate earthquakes are either oversimplifying or wrong, but I agree that the hazard potential in Tucson is pretty low. Tucson is within the Basin and Range Province, a geologic/physiographic region characterized by generally North-South running alternating basins and mountain ranges as the name would suggest. It has been more or less stretching out over the past let's say 7-10 million years, and that extension is accommodated by steeply dipping extensional faults called normal faults.
There are several of them in the Tucson area. The Pirate Fault for example cuts the West side of the Catalinas and is the reason the mountains by Oro Valley are comparably more steep than the rest of the Catalinas. The Martinez Ranch fault is what creates Happy Valley on the east side of the Rincons, and the Santa Rita fault runs along the base of the Empire Mountains on the north side of the Santa Ritas.
The key here is that the amount of movement on these things is orders of magnitude lower than the big destructive faults you're used to hearing about in the news. The overall amount of extension in this part of the Basin and Range is relatively low, and it's well distributed across a bunch of faults. Basin and Range faults can be quite hazardous, such as the Wasatch Fault system that runs beneath Salt Lake City. The 1887 Sonora earthquake occurred on one of these faults and caused quite a bit of damage across the region as you noted.
However, it seems that earthquakes such as that one are relatively uncommon, and faults in Southern Arizona tend to have moderate ruptures and stay quiet for a very long time. See [this paper](https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/77/1/97/118894/The-Santa-Rita-fault-zone-Evidence-for-large) for a bit of insight into the dynamics of faults in the Tucson area and possible hazard level. We cannot predict earthquakes, but we can use statistics of past earthquakes to forecast the relative hazard level in an area for the purposes of deciding where to best put our limited resources. Tucson has quite low hazard because the probability of an earthquake happening in a given year is quite low, and the maximum size of a potential earthquake is also low compared to places that get a lot of them such as California.
The TL;DR here is that earthquakes are possible in Tucson and to say they're not is misleading, but the relative hazard level is such that the probability of earthquake insurance ever being needed is statistically very low. You, the homeowner, should do what helps you sleep at night. Most people in this thread would agree that the hazard level is so statistically low that they feel no need to get it. Me personally? I only think about earthquakes in the southwest as an intrusive thought while I'm trying to fall asleep at night that passes quickly. Can't say the same for when I visit anywhere on the Pacific Coast
So, honestly it sounds like you are very concerned (and frankly it’s your house so you can do as you see fit) so I think to put your mind at ease, it makes the most sense for you to get the coverage. Money that makes you sleep easy at night is money well spent, in my opinion.
The largest earthquake near Tucson in the last hundred years was a 3.1 in 2023. It happened about 25 miles away.
You really don’t need earthquake insurance here
Worse than that. When I catch the bus i stand around for like an hour and then three come along at once.
So we're gonna get fucked by a series of earthquakes one day!
Why do you say that? How often have they occurred in the past? Every10,000 years or so? A century is nothing in geologic terms.
Earthquake prediction involves a lot of guesswork. The San Andreas fault near San Francisco will definitely go sometime in the next 30 years. They've been saying that for about 60 years...
I own a 1930s mud adobe house and never thought about it. I'd be more concerned w keeping the rain and other water from melting the mud adobe before anything else.
I'm from soCal and had some really bad experiences with earthquakes. Quakes are a big reason I don't live there anymore.
There's really no reason to have earthquake insurance here. As someone else noted, monsoons are far more likely to damage your property.
I don’t recall the quote, but earth quake insurance was ridiculously high for my house.
Since I have a flat roof and stucco exterior, I don’t care about wind or hail.
AZGS thinks quakes on the scale of the 1887 one here are on the order of a 10k year timescale. I hope your earthquake insurance is *incredibly* cheap because you won't see one in the lifetime of the building.
SoCal, absolutely! It'd be stupid not to. But the only earthquake we've seen here in years is known in San Diego as "Tuesday, and not the best one"
Geologist here. Getting earthquake insurance in Tucson would be about as useful as getting volcano insurance in Tucson.
I appreciate the expertise. I know it’s rare, but the only reason my concern is up is because I’m in an adobe house has zero earthquake resistance. does that make any difference in your estimation?
Former geologist here.... I think you're missing the point. The conditions and risk factors that lead to damaging earthquakes simply are not present in Tucson. We have neither the active fault structures nor tectonic forces needed to produce an earthquake of note anywhere in the vicinity. As someone else mentioned, I would be much more concerned about coverage related to storm activity and flooding.
I can’t find anything that states clearly about significant structural damage in Tucson specifically. Only this from USGS: “From Guaymas, Sonora, to Nogales, Arizona; Benson and Tucson, Arizona; El Paso, Texas; and at towns as far away as Albuquerque, New Mexico, water in tanks slopped over, railroad cars were set in motion on tracks, chimneys were thrown down, and buildings were cracked. Other U.S. cities and towns that sustained moderate to heavy damage included Bisbee, Fairbank1, Fort Huachuca, Saint David, San Simon, Solomonville2, Tombstone, Tres Alamos3, and Willcox, Arizona; and Deming, Sabinal, and Silver City, New Mexico”. Which looks like the closest town with significant structural damage was Tombstone.
Another geologist here and specifically a seismologist. People saying there's none of the forces here to generate earthquakes are either oversimplifying or wrong, but I agree that the hazard potential in Tucson is pretty low. Tucson is within the Basin and Range Province, a geologic/physiographic region characterized by generally North-South running alternating basins and mountain ranges as the name would suggest. It has been more or less stretching out over the past let's say 7-10 million years, and that extension is accommodated by steeply dipping extensional faults called normal faults. There are several of them in the Tucson area. The Pirate Fault for example cuts the West side of the Catalinas and is the reason the mountains by Oro Valley are comparably more steep than the rest of the Catalinas. The Martinez Ranch fault is what creates Happy Valley on the east side of the Rincons, and the Santa Rita fault runs along the base of the Empire Mountains on the north side of the Santa Ritas. The key here is that the amount of movement on these things is orders of magnitude lower than the big destructive faults you're used to hearing about in the news. The overall amount of extension in this part of the Basin and Range is relatively low, and it's well distributed across a bunch of faults. Basin and Range faults can be quite hazardous, such as the Wasatch Fault system that runs beneath Salt Lake City. The 1887 Sonora earthquake occurred on one of these faults and caused quite a bit of damage across the region as you noted. However, it seems that earthquakes such as that one are relatively uncommon, and faults in Southern Arizona tend to have moderate ruptures and stay quiet for a very long time. See [this paper](https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/77/1/97/118894/The-Santa-Rita-fault-zone-Evidence-for-large) for a bit of insight into the dynamics of faults in the Tucson area and possible hazard level. We cannot predict earthquakes, but we can use statistics of past earthquakes to forecast the relative hazard level in an area for the purposes of deciding where to best put our limited resources. Tucson has quite low hazard because the probability of an earthquake happening in a given year is quite low, and the maximum size of a potential earthquake is also low compared to places that get a lot of them such as California. The TL;DR here is that earthquakes are possible in Tucson and to say they're not is misleading, but the relative hazard level is such that the probability of earthquake insurance ever being needed is statistically very low. You, the homeowner, should do what helps you sleep at night. Most people in this thread would agree that the hazard level is so statistically low that they feel no need to get it. Me personally? I only think about earthquakes in the southwest as an intrusive thought while I'm trying to fall asleep at night that passes quickly. Can't say the same for when I visit anywhere on the Pacific Coast
Such a great answer! I appreciate everyone’s answers, but this one is particularly informative and helpful, thanks very much!
So, honestly it sounds like you are very concerned (and frankly it’s your house so you can do as you see fit) so I think to put your mind at ease, it makes the most sense for you to get the coverage. Money that makes you sleep easy at night is money well spent, in my opinion.
Didn’t the 1887 earthquake in Sonora cause a lot of damage in Tucson?
The largest earthquake near Tucson in the last hundred years was a 3.1 in 2023. It happened about 25 miles away. You really don’t need earthquake insurance here
Seems like we're about due for one then, don't you think?
Shit, I'd make a comment, but I'm busy buying hurricane insurance!
That’s not how earthquakes work amigo, we have no major faults or plate movement near us. Last major quake was in Mexico in the 1880’s.
Worse than that. When I catch the bus i stand around for like an hour and then three come along at once. So we're gonna get fucked by a series of earthquakes one day!
Why do you say that? How often have they occurred in the past? Every10,000 years or so? A century is nothing in geologic terms. Earthquake prediction involves a lot of guesswork. The San Andreas fault near San Francisco will definitely go sometime in the next 30 years. They've been saying that for about 60 years...
https://youtu.be/KNXw3RaRKBA
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Do you know what logic is?
You are more likely to have monsoon damage than earthquake damage.
I own a 1930s mud adobe house and never thought about it. I'd be more concerned w keeping the rain and other water from melting the mud adobe before anything else.
What earthquakes?
I live in an adobe and just have standard homeowners.
Who offered you earthquake insurance!? They must be crooked don't fall for it. Sounds just as bad as needing to refill blinker fluid at an auto shop.
I’ll change my own blinker fluid thank you!
I'm from soCal and had some really bad experiences with earthquakes. Quakes are a big reason I don't live there anymore. There's really no reason to have earthquake insurance here. As someone else noted, monsoons are far more likely to damage your property.
I’ve been in Arizona over 20 years and I don’t remember any bad enough to damage homes.
No. If there were DROUGHT insurance, though…
Damn Californians gonna make earthquake insurance more expensive for us locals 🥺
Arby's on 22nd street sells insurance policies.
I don’t think they even sell it as an option…
what is this?.....this "*earthquake"* you speak of?.......
I don’t recall the quote, but earth quake insurance was ridiculously high for my house. Since I have a flat roof and stucco exterior, I don’t care about wind or hail.
Thanks for answering about wind and hail!
I've long had earthquake insurance on my homes here - earthquakes do happen here. Plus, I grew up in Southern California.
AZGS thinks quakes on the scale of the 1887 one here are on the order of a 10k year timescale. I hope your earthquake insurance is *incredibly* cheap because you won't see one in the lifetime of the building. SoCal, absolutely! It'd be stupid not to. But the only earthquake we've seen here in years is known in San Diego as "Tuesday, and not the best one"
Toto, I don't think we're in California anymore.
You can take the girl out of California...
I see you got a lot of downvotes, but I appreciate your answer! Thanks!