I had the recollection that at least in terms of earthquake risk, the mid-Atlantic region is not nearly as bad for severe earthquakes as the Pacific, since the mid-Atlantic is an expanding / divergent fault. I.e. material gets pushed up gradually and the plates are politely moving away from one another. This is supposed to be less catastrophic compared to subduction where big stresses build up and get released suddenly when things break. Is that generally right?
But of course, that is just the earthquake part, doesn't speak to the volcano or tsunami risk of big mountains erupting or falling into the ocean. I guess this current story is about the possibility of lava/ash, like what happened to the suburbs downslope of Kilauea or Soufriere Hills in the last couple years.
Edit, actually watching one of the videos linked by other commenters, it looks remarkably like Molokai and people living (gulp) at the bottom of steep drop-off/valleys.
Earth science PhD here - you're pretty much right, but Atlantic oceans can still be bad.
Most earthquakes are caused by tectonic plate motion.
The biggest earthquakes (>M9, e.g. Japan 2011) occur at subduction zones where an oceanic plate collides with and dives underneath a continental plate. Japan, South&Central America, New Zealand, and Malaysia are the biggest and most common examples. Two plates pushing against each other allow large energy to build, which can be released suddenly and catastrophically.
Large earthquakes (M7-8, e.g. San Francisco 1906) can still occur along strike-slip faults, where two plates are sliding past each other. However, because the plates are sliding, these faults usually cannot build enough energy for extremely large earthquakes (>M9.0). San Andreas fault in California is the most well known strike-slip fault and runs through both LA and SF, and has caused plenty of damage partly because the faults run directly through population centers.
The Azores lie on top of strike slip and expanding (normal) faults. Thus, they are not likely to experience the largest earthquakes (M9), but could be hit but a M8 which can still be devastating, especially if buildings are not constructed with earthquake safety in mind.
In addition, there is a high risk of any earthquake triggering an underwater landslide since the Azores are a mid-ocean island chain. This could cause a tsunami which could damage far-away locations.
As far as lava/ash risk -- generally the biggest risk is from explosive eruptions forming into a fast-moving cloud of ash and mud called a "pyroclastic flow" or "lahar". [1] These can travel faster than a car and blanket everything in their path in a boiling, burning cloud. Think Mt St Helens or Mt Vesuvius. However, only certain types of volcanoes are at risk of this type of eruption -- Hawaii for example erupts as smooth, oozing lava flows -- and I don't know if the Azores are at risk for this kind of eruption.
Notes on safety:
For earthquake safety, the best cure is preparation. Most injuries and death occur from items falling on top of people during the shaking. Secure shelves and items on walls. Avoid living in structures on poles as they are prone to collapse (e.g. apartments with parking garage on first level). Avoid living in marshy areas or seaside land constructed with landfill (due to liquefaction) or on steep slopes (due to landslides).
For tsunamis, if there is a warning, head to high ground further inland if possible, or move to upper stories of the roof of structures.
Is there some sort of correlation with uptick in seismic activity, I mean are we in seeing normal activity, or is there indeed a lot more going on than 'usual'?
Maybe it's just some synchronicity and I'm just more 'aware' because of all the other natural disasters, and non-natural, but it just 'feels' like something big is coming because of all the volcanoes, tsunami's, and other reports of activity.
Also, how much does climate change affect volcanoes, and earthquakes?
One big concern I have is the potential for a big boom that can be heard for thousands of miles (like the recent Tongan eruption), which would be in range of a certain trigger happy sociopath that wants a reason to use his nukes. I'm not sure if either of those scenarios (big boom or misinterpreted nuke signals) is realistic, but I'll be worried until it is effectively a non-issue.
At first I thought that was kinda crazy, cause he'd 'know' pretty quick it was a volcano, but then I realized some of the 'deadmen switches' are triggered by seismic actions, or at least that's what I'd heard/read elsewhere, maybe it's not. Would kinda suck if something automatically launched because of a geological event, not an actual attack, and it actually wasn't Putin causing it.
Two conditions have to be met for a deadman switch to work. Firstly, its armed. Secondly, a FAILURE TO CONTACT event of some kind. (my words). But, its not momentary fail. Its got trigger conditions and gates. It isn't an immediate response option. Its the "at the end..." logic in MAD.
So for an earthquake there would be a loud "boom" and there might be some initial failure to contact. But then there would be cell service, satellite, ultra-long wavelength comms, all kinds of alternate paths home. There would be a distinct lack of radiological problems. A complete absence of any sign of protracted single-strike attack at scale on your nation state, the continuance of evident non-nuclear life as normal (normal! I mean who had pandemics in their 2022 yearbook before 2020...)
Having a deadman switch which was capable of being triggered solely by a local geological event absent all other context would be very bad design.
1755 earthquake (and tsunami) nearly destroyed the whole city and was probably one of the most deadliest in history. It was also one of the first quakes to be studied scientifically [0]
Sooner or later it will hit Lisbon again, scientists say. As a Portuguese I'm very afraid the city is not prepared for something with an estimated magnitude of 7.7–9.0...
It did destroy a significant portion of the city, and the rebuilding was a centerpoint of the Marquis de Pombal, whose expanding rule/influence was largely won based on his skill at using the rebuild to enact all manner of political change in a short period of time.
Comments
I had the recollection that at least in terms of earthquake risk, the mid-Atlantic region is not nearly as bad for severe earthquakes as the Pacific, since the mid-Atlantic is an expanding / divergent fault. I.e. material gets pushed up gradually and the plates are politely moving away from one another. This is supposed to be less catastrophic compared to subduction where big stresses build up and get released suddenly when things break. Is that generally right?
But of course, that is just the earthquake part, doesn't speak to the volcano or tsunami risk of big mountains erupting or falling into the ocean. I guess this current story is about the possibility of lava/ash, like what happened to the suburbs downslope of Kilauea or Soufriere Hills in the last couple years.
Edit, actually watching one of the videos linked by other commenters, it looks remarkably like Molokai and people living (gulp) at the bottom of steep drop-off/valleys.
Earth science PhD here - you're pretty much right, but Atlantic oceans can still be bad.
Most earthquakes are caused by tectonic plate motion.
The biggest earthquakes (>M9, e.g. Japan 2011) occur at subduction zones where an oceanic plate collides with and dives underneath a continental plate. Japan, South&Central America, New Zealand, and Malaysia are the biggest and most common examples. Two plates pushing against each other allow large energy to build, which can be released suddenly and catastrophically.
Large earthquakes (M7-8, e.g. San Francisco 1906) can still occur along strike-slip faults, where two plates are sliding past each other. However, because the plates are sliding, these faults usually cannot build enough energy for extremely large earthquakes (>M9.0). San Andreas fault in California is the most well known strike-slip fault and runs through both LA and SF, and has caused plenty of damage partly because the faults run directly through population centers.
The Azores lie on top of strike slip and expanding (normal) faults. Thus, they are not likely to experience the largest earthquakes (M9), but could be hit but a M8 which can still be devastating, especially if buildings are not constructed with earthquake safety in mind.
In addition, there is a high risk of any earthquake triggering an underwater landslide since the Azores are a mid-ocean island chain. This could cause a tsunami which could damage far-away locations.
As far as lava/ash risk -- generally the biggest risk is from explosive eruptions forming into a fast-moving cloud of ash and mud called a "pyroclastic flow" or "lahar". [1] These can travel faster than a car and blanket everything in their path in a boiling, burning cloud. Think Mt St Helens or Mt Vesuvius. However, only certain types of volcanoes are at risk of this type of eruption -- Hawaii for example erupts as smooth, oozing lava flows -- and I don't know if the Azores are at risk for this kind of eruption.
Notes on safety:
For earthquake safety, the best cure is preparation. Most injuries and death occur from items falling on top of people during the shaking. Secure shelves and items on walls. Avoid living in structures on poles as they are prone to collapse (e.g. apartments with parking garage on first level). Avoid living in marshy areas or seaside land constructed with landfill (due to liquefaction) or on steep slopes (due to landslides).
For tsunamis, if there is a warning, head to high ground further inland if possible, or move to upper stories of the roof of structures.
[1] https://www.usgs.gov/observatories/cascades-volcano-observat... earthquake safety: https://www.calacademy.org/explore-science/how-to-prepare-fo... tsunami safety: https://www.ready.gov/tsunamis
Quibble - pyroclastic flows and lahars are very different things.
The former is the boiling burning cloud of gas and tephra, the latter is a slurry of water and tephra.
Is there some sort of correlation with uptick in seismic activity, I mean are we in seeing normal activity, or is there indeed a lot more going on than 'usual'?
Maybe it's just some synchronicity and I'm just more 'aware' because of all the other natural disasters, and non-natural, but it just 'feels' like something big is coming because of all the volcanoes, tsunami's, and other reports of activity.
Also, how much does climate change affect volcanoes, and earthquakes?
Well, broadly speaking, an earthquake on one fault can alter shear and stress on other faults - up or down though.
As for climate change... well, maybe, there's definitely mechanisms whereby it can change stress on rock, but how much of an effect it has, no-one can really say. This is a good round up. https://climate.nasa.gov/news/2926/can-climate-affect-earthq...
Would it be possible to trigger an earthquake by undersea drilling in a heterogenous or diffuse fault zone?
Asking for a reason.
https://www.istc.int/en/project/CCBC05C670F935B0C32570040042...
https://www.bbc.com/future/article/20171121-why-russia-is-se...
Azores, not Azov, not Arctic. This place is closer to New York than the Russian Arctic. No sea ice. No drilling (which would be easy to detect).
Yes, Azores. Submarines are not limited to operating in war zones. Sea ice is not required for drilling, it happens on the ocean floor.
There was a Russian navy submarine in the Sea of Japan right before the recent earthquake. Maybe it is something to look into.
There was a pyroclastic flow event the last time this volcano erupted (early 1800s), and it killed something like 30 people.
Edit: https://en.m.wikipedia.org/wiki/Bocas_de_Fogo
One big concern I have is the potential for a big boom that can be heard for thousands of miles (like the recent Tongan eruption), which would be in range of a certain trigger happy sociopath that wants a reason to use his nukes. I'm not sure if either of those scenarios (big boom or misinterpreted nuke signals) is realistic, but I'll be worried until it is effectively a non-issue.
At first I thought that was kinda crazy, cause he'd 'know' pretty quick it was a volcano, but then I realized some of the 'deadmen switches' are triggered by seismic actions, or at least that's what I'd heard/read elsewhere, maybe it's not. Would kinda suck if something automatically launched because of a geological event, not an actual attack, and it actually wasn't Putin causing it.
Two conditions have to be met for a deadman switch to work. Firstly, its armed. Secondly, a FAILURE TO CONTACT event of some kind. (my words). But, its not momentary fail. Its got trigger conditions and gates. It isn't an immediate response option. Its the "at the end..." logic in MAD.
So for an earthquake there would be a loud "boom" and there might be some initial failure to contact. But then there would be cell service, satellite, ultra-long wavelength comms, all kinds of alternate paths home. There would be a distinct lack of radiological problems. A complete absence of any sign of protracted single-strike attack at scale on your nation state, the continuance of evident non-nuclear life as normal (normal! I mean who had pandemics in their 2022 yearbook before 2020...)
Having a deadman switch which was capable of being triggered solely by a local geological event absent all other context would be very bad design.
If I'm not mistaken there was an earthquake in 17xx that almost erased Lisbon.
Still, it really appears that sismic activity in the Pacific is much more frequent.
1755 earthquake (and tsunami) nearly destroyed the whole city and was probably one of the most deadliest in history. It was also one of the first quakes to be studied scientifically [0]
Sooner or later it will hit Lisbon again, scientists say. As a Portuguese I'm very afraid the city is not prepared for something with an estimated magnitude of 7.7–9.0...
[0] https://en.wikipedia.org/wiki/1755_Lisbon_earthquake
I was wondering, given that quake, do Portugal's building codes now incorporate seismic standards?
Yes but since 2020 it's moving to European construction standards [0]
[0] https://en.wikipedia.org/wiki/Eurocode_8:_Design_of_structur...
The reconstruction of the city involved some of the first intentionally anti-seismic building methods.
https://en.wikipedia.org/wiki/Pombaline_style
It did destroy a significant portion of the city, and the rebuilding was a centerpoint of the Marquis de Pombal, whose expanding rule/influence was largely won based on his skill at using the rebuild to enact all manner of political change in a short period of time.
1755, and it really did obliterate the city. They had to rebuild it all, it was all gone.
I thought transform boundaries were the big earthquake risk (not that there is none at convergent boundaries).
At least that's what I remember from my 8th grade earth science class. I could be really wrong.