That is _really_ big. It will likely crack the top 8 ever recorded. https://en.wikipedia.org/wiki/Lists_of_earthquakes
Wow. The same region had a 9.0 in 1952
M8.7 earthquake in Western Pacific, tsunami warning issued
111–120 of 266 posts
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#112Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#113Earlier quoted context omitted.
Is height the only thing that matters? Presumably 1x 2m wave is less impactful than 10 x 1m waves spread 20 seconds apart?
I'm surprised so many people don't understand what tsunamis are. It's a "wave" created by a sudden shift in the Earth's crust. Imagine, suddenly, water on each of side of that split is now at different heights and has to equalize. It's much closer to just removing a dam that is holding back water equal in height to the new difference between the sea floors. What you get is not a "wave" but a wall of water.
> I'm surprised so many people don't understand what tsunamis are.
“I’m Surprised so many people don’t know what ‘X’ is/are isn’t a very nice thing to say. Your comment could have done without that, the rest of it would have been fine.
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#114Earlier quoted context omitted.
Is height the only thing that matters? Presumably 1x 2m wave is less impactful than 10 x 1m waves spread 20 seconds apart?
I'm surprised so many people don't understand what tsunamis are. It's a "wave" created by a sudden shift in the Earth's crust. Imagine, suddenly, water on each of side of that split is now at different heights and has to equalize. It's much closer to just removing a dam that is holding back water equal in height to the new difference between the sea floors. What you get is not a "wave" but a wall of water.
This doesn't make sense to me intuitively. It must be a wave.
Imagine you have a fault line. There is a left side and a right side to the fault line. If the left side lowers with a shift then that shift MUST be localized to the area around the fault. Because if it wasn't then that means there's an elevation change across the board for everything to the left of the fault. You see how that doesn't make sense? So if the entire country of japan was on the left side of the fault then the entire country of japan shifts in elevation which is unrealistic.
So that means, if what you say is semi-true then the shift in elevation is localized to the area left along the fault but the elevation further left remains the same. It's like a slight dip or bump along the fault line. It must be like this because the alternative is just unrealistic. This MUST be what happens when tectonic plates "shift". You won't see the ENTIRE plate shifting in elevation.
With naive logic, one would think that the water simply fills the localized gap but given how deep the ocean is relative to the actual shift way down in the abyss I'm betting if you were on a boat on top of the fault you wouldn't notice anything. But the movement does create a slight imperceptible "filling" that you don't notice. This is a "wave" but it's invisible.
The wave will translate leftward if the movement of the "shift" was sort of in that direction, but you don't see it. BUT as the sea floor gets nearer and nearer to the surface of the ocean the energy of the wave gets squuezed into less and less ocean water mass (i'm remembering how tsunamis work now) and THEN it becomes visible. Right? Just imagine a sideways cross section. As the tiny wave travels from big ocean with huge depth to coastline with no depth the energy of the wave gets concentrated into a thinner and thinner layer of water.
My intuition just sort of converged with my obscure memory of how tsunamis work so I'm pretty sure this is what's going on.
So it is indeed a "wave" that is acting on wave like phenomena beyond simply "filling a gap". In fact say there's an elevation lowering on the left side of the fault by 1 meter. The resulting wave on the coast line hundreds of miles away will be a wave that extends upward by MORE then 1 meter above sea level which is the opposite of water "filling up a gap." That's totally a wave.
Additionally water from tsunamis always recede. This wouldn't happen if the "wall of water" was simply equalizing. If that's the case the water would never recede.
Any expert who says otherwise, let me know.
edit: Actually why the fuck am I using my intuition to explain it? Just cite a source:
https://www.noaa.gov/explainers/science-behind-tsunamis
tsunamis are 100% waves as explained in the link. Anyone who says otherwise clearly doesn't know what they are talking about, that includes the person I'm responding to. End of story.
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#115Earlier quoted context omitted.
I'm surprised so many people don't understand what tsunamis are. It's a "wave" created by a sudden shift in the Earth's crust. Imagine, suddenly, water on each of side of that split is now at different heights and has to equalize. It's much closer to just removing a dam that is holding back water equal in height to the new difference between the sea floors. What you get is not a "wave" but a wall of water.
> I'm surprised so many people don't understand what tsunamis are. “I’m Surprised so many people don’t know what ‘X’ is/are isn’t a very nice thing to say. Your comment could have done without that, the rest of it would have been fine.
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Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#116Earlier quoted context omitted.
Japanese news reporting during disaster scenarios is something to behold. The screen is filled with data and blinking like a Bloomberg Terminal.
My favorite is the NHK reporters standing in the middle of absolutely nowhere with their NHK helmets. No matter what the event, there is a reporter wearing a helmet.
Also, the very first thing they say when the camera cuts to them is that they are standing in designated evacuation zone X that's Y meters above sea level.
Then the cameraman zooms at the ocean, which is blurry and shaky because they're in the designated evacuation zone Z km away from the coast.
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#117My wife decided to not travel to Japan due to an impending warning from a manga for July 2025. I have been making fun of her all month only to get this tsunami warning now! https://en.wikipedia.org/wiki/July_2025_Japan_megaquake_prop... . > The 2021 reprint capitalizing off this revived popularity warned of a "real disaster" in July 2025, causing a minor case of mass hysteria in 2025 when summer trips to Japan from E…
Well, you can continue to make fun of her because, fortunately, this has turned out to be basically nothing (for Japan, anyway).
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#118Waves at Midway Atoll and Guam are reported to be 3ft (1m) amplitude by Hawaii Governor Josh Green as of 6:24pm Hawaii Time
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#119Earlier quoted context omitted.
I'm surprised so many people don't understand what tsunamis are. It's a "wave" created by a sudden shift in the Earth's crust. Imagine, suddenly, water on each of side of that split is now at different heights and has to equalize. It's much closer to just removing a dam that is holding back water equal in height to the new difference between the sea floors. What you get is not a "wave" but a wall of water.
This doesn't make sense to me intuitively. It must be a wave. Imagine you have a fault line. There is a left side and a right side to the fault line. If the left side lowers with a shift then that shift MUST be localized to the area around the fault. Because if it wasn't then that means there's an elevation change across the board for everything to the left of the fault. You see how that doesn't make sense? So if the…
https://www.youtube.com/watch?v=wAFYVpX45xs
Here's a video of what it looks like from the 2011 event, from the POV of the coast guard approaching it. Waves don't typically look like a sheet has been flapped across one front of the entire horizon of what is visible on the ocean
Re: M8.7 earthquake in Western Pacific, tsunami warning issued
#120I was parked at Selzer beach in Seaside, Oregon when the earthquake/tsunami news hit around 7:30pm. Within 30 minutes it was impossible to buy gas without queueing and now there is a pretty steady stream of cars heading out of town. As of 9pm it’s been upgraded to a warning up and down the coast.
I was just thinking of tsunamis the two days ago in the Del Rey beach parking lot, where I noticed the locals seemed to park at the exit end of the lot, facing out. I moved my car to match because that just makes sense.