I live in Misawa (https://en.wikipedia.org/wiki/Misawa,_Aomori) and work in Rokkasho (https://en.wikipedia.org/wiki/Rokkasho), which is the area where the earthquake hit the strongest. It was quite violent, apparently the strongest earthquake ever recorded in the region. My house suffered no damage other than a few things falling off the cabinets, and I could sleep soundly afterwards, but lets see today at work.
Was in a hotel in Sapporo, almost got thrown out of bed. Lot of people in the hotel lobby now.
Considering leaving Hokkaido by air if a Hokkaido and Sanriku Subsequent Earthquake Advisory is issued, don't really want to be in a potential megaquake.
People were freaking about the July megaquake prophecy and nothing happened. Trying to time it is silly, just chill and enjoy your stay, you'll probably be fine.
This is different than the July megaquake prophecy, which was indeed dumb. With a strong quake like this there will be aftershocks. Most will be small, but there is a risk (about 5% according to the USGS) of an even stronger quake than the first within the next week or so [1].
I agree the parent will likely be fine, but it can be stressful in the aftermath of a large quake. And if they want to leave the area and have the opportunity to do so calmly and safely, I think that’s justified.
I'm not a geologist, but this was pretty deep (44.1k) so not likely a foreshock right? Any actual geologists have a thought here? I know we have seen some indications that foreshocks can happen before megathrust earthquakes but it would need to be at the interface right? This looks like it is just the subducted slab deep down which in the 'intermediate zone' so not impacting the interface that 'slips' in a megathrust earthquake. (again, not a geologist) Now there have been, by that I mean just now, a 6.6 aftershock that was only 10km deep so that is potentially more concerning?
Good luck, the Sapporo Chitose airport is closed for inspection of both runways.
BTW, you are safer in hotel than outside. No need to stay in lobby, go to bed, just protect your head. I experienced much bigger one in Sapporo in 2018.
When I moved to SF, someone told me that the three most important things you can do for earthquake safety are:
- make sure nothing can fall on you when you're in bed (no mounted artwork above the headboard; no lamps etc on side tables that are high enough to fall on you)
- make sure you have footwear in your bedroom, so you can be mobile if there's broken glass everywhere
- store extra drinking water somewhere (I used a 6-gallon carboy that I periodically refilled)
Probably there are other good things to do, but all those made a lot of sense to me. Most of us spend more time in bed than in any other fixed location, so making sure the bed is a safe place rings true. And water is life.
This would be the tenth major earthquake (7+ magnitude) along the Pacific ring of fire this year.
With the Kamchatka and other earthquakes in the news recently I had a fear that were building to some major event but turns out that this year is about average if not slightly below average for major quakes along the ring of fire.
I heard that smaller (relative) earthquakes actually lower the prob of larger ones, so maybe it is a good thing? A bunch of 7.X earthquakes in the ocean are not going to be hugely destructive.
On the one hand earthquakes remove tension from the earth’s crust and release energy that can’t be used in future shocks.
On the other hand, if a shock doesn’t release all energy it may come to rest in a relatively weak spot that will soon give away again (https://en.wikipedia.org/wiki/Earthquake_swarm: “The Matsushiro swarm lasted from 1965 to 1967 and generated about 1 million earthquakes. This swarm had the peculiarity of being sited just under a seismological observatory installed in 1947 in a decommissioned military tunnel. It began in August 1965 with three earthquakes too weak to be felt, but three months later, a hundred earthquakes could be felt daily. On 17 April 1966, the observatory counted 6,780 earthquakes, with 585 of them having a magnitude great enough to be felt, which means that an earthquake could be felt, on average, every two and a half minutes.”)
Because of that, I think an earthquake will increase the probability of one occurring again soon, but decrease its strength.
> A bunch of 7.X earthquakes in the ocean are not going to be hugely destructive.
New Zealand’s 5th most deadly disaster was Christchurch’s 6.2 which killed 185 people. It was a shallow aftershock from a larger, less destructive quake.
Almost all energy released in earthquakes is released in the biggest ones. No realistic number of smaller quakes is ever going to add up to even the single biggest earthquake ever recorded.
That's correct, if relatively small earthquakes would stop that could be the precursor to a much bigger one. It's like releasing tension gradually rather than all at once.
Somewhat offtopic curiosity: Is there anything that Japanese fishkeepers do to keep the water and livestock inside the tank during earthquakes? Here we have no such risk for earthquakes, so a 600lb tank of water 4ft off the ground isn't much of an issue, even when bumped. I'd imagine earthquakes of this frequency could complicate that.
I have a 60L fish tank in my Tokyo apartment on around the 10th floor. It's sitting on stand that is not bolted to the wall. I have several friends with similar setups.
In the last 6 years there have been two or three earthquakes that caused enough water to slosh on to the floor.
Of those only the 2021 Fukushima earthquake caused any fish to slosh out - perhaps 10 medaka if I recall correctly. Luckily I was home and I was able to save all the fish, however there was one adult red cherry shrimp that didn't make it because I had trouble picking it up off the floor. I cleaned up the water with some paper towels and it didn't seem to cause any lasting damage.
I think if I had a 600 lb (270L?) tank or expensive fish though I would probably have a different perspective.
Does anyone else find the way of using tsunami.gov totally baffling? It tells the user almost nothing, and the target of all the hrefs for the supposed messages listed in the map is just the tsunami.gov homepage again. The entire above-the-fold is occupied by the map, and the map tells the user nothing.
Is 1 meter bad? In context it seems to be missing what kind of waves normally hit the coast line, and what kind tide differences exist, and what the current water level is when the wave hit.
What is a typical maximum wave height during hurricane seasons in north of japan?
Today I got served this video "Earthquake and Liquefaction his Urayasu, Chiba 3/11/2011" [0], which is from the earthquake which caused the huge tsunami in Japan.
The flood videos of towns, cars, and people being violently washed away are way scarier IMO.
Urayasu looks built on the water and all I see in the linked video is a threshold condition where the water is just barely peeking up through the ground below. People are still walking around, cars driving. There are far more chaotic and destructive scenes on youtube from that tsunami.
Different kinds of scary. The tsunami is clearly more dangerous as an actual threat, but it basically looks and works like a flood. This is a pretty familiar threat.
We think the ground is familiar too. So watching it change into something else, a squirming alien beast, is a different kind of fear. It violates your assumptions about what is safe, about what is possible at all.
Terrifying. I know that Japan is earthquake-proofing its architecture but how about the underground infra? Do they have to dig and redo the pipes? The cables seem to be mostly overground (at least in this video) and are probably easier to repair (oldschool infra ftw).
> The cables seem to be mostly overground (at least in this video) and are probably easier to repair (oldschool infra ftw).
In Japan cables are (still) mostly overground. Use of underground is still a relatively new topic as addressed by the TEPCO website[1]. The first footer on the bottom of that page provides a nice TL;DR of the state of play:
The plans for underground conversion have consisted of "Plan for Underground Conversion of Power Lines", which covered three terms from FY 1986 to FY 1998, followed by the "New Plan for Underground Conversion of Power Lines" from FY 1999 to FY 2003, and then the "Plan for the Removal of Utility Poles" from FY 2004 to FY 2008. Based on these plans, approximately 7,700 km of lines all across Japan were placed underground over 23 years by the end of FY 2008 (with TEPCO responsible for approximately 3,500 km).
Currently, we are consulting with related personnel regarding items such as locations for conversion as based on the new "Guidelines for the Removal of Utility Poles" established in FY 2009.
Readit News
Considering leaving Hokkaido by air if a Hokkaido and Sanriku Subsequent Earthquake Advisory is issued, don't really want to be in a potential megaquake.
I agree the parent will likely be fine, but it can be stressful in the aftermath of a large quake. And if they want to leave the area and have the opportunity to do so calmly and safely, I think that’s justified.
[1] https://www.usgs.gov/faqs/what-probability-earthquake-a-fore...
BTW, you are safer in hotel than outside. No need to stay in lobby, go to bed, just protect your head. I experienced much bigger one in Sapporo in 2018.
- make sure nothing can fall on you when you're in bed (no mounted artwork above the headboard; no lamps etc on side tables that are high enough to fall on you)
- make sure you have footwear in your bedroom, so you can be mobile if there's broken glass everywhere
- store extra drinking water somewhere (I used a 6-gallon carboy that I periodically refilled)
Probably there are other good things to do, but all those made a lot of sense to me. Most of us spend more time in bed than in any other fixed location, so making sure the bed is a safe place rings true. And water is life.
Deleted Comment
0.7m observed about 40 minutes ago.
With the Kamchatka and other earthquakes in the news recently I had a fear that were building to some major event but turns out that this year is about average if not slightly below average for major quakes along the ring of fire.
On the other hand, if a shock doesn’t release all energy it may come to rest in a relatively weak spot that will soon give away again (https://en.wikipedia.org/wiki/Earthquake_swarm: “The Matsushiro swarm lasted from 1965 to 1967 and generated about 1 million earthquakes. This swarm had the peculiarity of being sited just under a seismological observatory installed in 1947 in a decommissioned military tunnel. It began in August 1965 with three earthquakes too weak to be felt, but three months later, a hundred earthquakes could be felt daily. On 17 April 1966, the observatory counted 6,780 earthquakes, with 585 of them having a magnitude great enough to be felt, which means that an earthquake could be felt, on average, every two and a half minutes.”)
Because of that, I think an earthquake will increase the probability of one occurring again soon, but decrease its strength.
New Zealand’s 5th most deadly disaster was Christchurch’s 6.2 which killed 185 people. It was a shallow aftershock from a larger, less destructive quake.
The damage was huge.
https://en.wikipedia.org/wiki/2011_Christchurch_earthquake
So the only thing we can say for sure is that it is still extremely difficult to predict earthquakes.
Deleted Comment
In the last 6 years there have been two or three earthquakes that caused enough water to slosh on to the floor.
Of those only the 2021 Fukushima earthquake caused any fish to slosh out - perhaps 10 medaka if I recall correctly. Luckily I was home and I was able to save all the fish, however there was one adult red cherry shrimp that didn't make it because I had trouble picking it up off the floor. I cleaned up the water with some paper towels and it didn't seem to cause any lasting damage.
I think if I had a 600 lb (270L?) tank or expensive fish though I would probably have a different perspective.
Shouldn't be too bad; USGS forecasts up to 1 meter tsunami.
https://www3.nhk.or.jp/nhkworld/en/news/weather-disaster/tsu...
What is a typical maximum wave height during hurricane seasons in north of japan?
I have rarely seen something as scary as this.
[0] https://www.youtube.com/watch?v=FGblnPeOXJg
Urayasu looks built on the water and all I see in the linked video is a threshold condition where the water is just barely peeking up through the ground below. People are still walking around, cars driving. There are far more chaotic and destructive scenes on youtube from that tsunami.
We think the ground is familiar too. So watching it change into something else, a squirming alien beast, is a different kind of fear. It violates your assumptions about what is safe, about what is possible at all.
In Japan cables are (still) mostly overground. Use of underground is still a relatively new topic as addressed by the TEPCO website[1]. The first footer on the bottom of that page provides a nice TL;DR of the state of play:
[1] https://www.tepco.co.jp/en/hd/about/facilities/distribution-...