Megatsunami Risk On the Rise As Glacial Melt Drives Landslides (theguardian.com) 50
An anonymous reader quotes a report from The Guardian: Just under a year ago, the east coast of Greenland was hit by a megatsunami. Triggered by a large landslide entering the uninhabited Dickson Fjord, the resulting tsunami was 200 meters high -- equivalent to more than 40 double-decker buses. Luckily no one was hurt, though a military base was obliterated. Now analysis of the seismic data associated with the event has revealed that the tsunami was followed by a standing wave, which continued to slosh back and forth within the narrow fjord for many days.
Angela Carrillo Ponce from the German Research Centre for Geosciences in Potsdam, analyzed the seismic data, recorded at earthquake monitoring stations more than 3,000 miles (5,000km) away, and found signals persisting long after the 16 September 2023 landslide event. Using satellite images and computer modeling, Ponce and her colleagues were able to confirm the presence of a standing wave of about 1 meter in height which lasted for more than a week.
Their findings, published in The Seismic Record, warn that climate change is accelerating the melt of Greenland's glaciers and permafrost, increasing the chance of landslides and subsequent megatsunamis. Smaller events have been observed a number of times in recent years, such as the rock avalanche into western Greenland's Karrat Fjord in 2017, which triggered a tsunami that flooded the village of Nuugaatsiaq, destroying 11 houses and killing four people.
Angela Carrillo Ponce from the German Research Centre for Geosciences in Potsdam, analyzed the seismic data, recorded at earthquake monitoring stations more than 3,000 miles (5,000km) away, and found signals persisting long after the 16 September 2023 landslide event. Using satellite images and computer modeling, Ponce and her colleagues were able to confirm the presence of a standing wave of about 1 meter in height which lasted for more than a week.
Their findings, published in The Seismic Record, warn that climate change is accelerating the melt of Greenland's glaciers and permafrost, increasing the chance of landslides and subsequent megatsunamis. Smaller events have been observed a number of times in recent years, such as the rock avalanche into western Greenland's Karrat Fjord in 2017, which triggered a tsunami that flooded the village of Nuugaatsiaq, destroying 11 houses and killing four people.
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ignorance like this is the problem, if it wasn't for the denial of the complicit, we'd have grasped the nettle
once again, the rich and powerful will wreck everything for everybody
Re: More bullcrap! (Score:4, Informative)
No good video, because the few people were a bit too busy running to film properly.
https://www.youtube.com/watch?... [youtube.com]
https://www.youtube.com/watch?... [youtube.com]
https://www.youtube.com/watch?... [youtube.com]
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No good video, because the few people were a bit too busy running to film properly.
https://www.youtube.com/watch?... [youtube.com]
https://www.youtube.com/watch?... [youtube.com]
https://www.youtube.com/watch?... [youtube.com]
Um, Military Base? Posted 7 Years ago?
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Ummm, tsunami in Greenland. You can pretty much imagine how many people are there hanging out at a deserted military base and what it looked like when the tsunami came.
Come to think of it, you can ask your favorite degenerative AI to produce a hallucination for you.
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Yes.
Also nowadays, footage from military installations is readily accessible to anyone interested.
I mean, you can immediately hook up to any security camera system running in just about any military facility and watch Generals Buck Turgidson and Jack Ripper inspecting the freshly painted green grass on the base.
Re: More bullcrap! (Score:4, Informative)
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People want entertainment. They think a tsunami far away is fun. Humanity, you can't help it.
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We can have these, but where are the equivalent in UFO videos?
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These are top-sikrit, of course. BUT THEY WILL LEAK!.
Or, in the words of a better person, THE TRUF WANNA BE FREE!
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Exactly Like the Worst Ocean Tsunamis (Score:5, Insightful)
They aren't tsunamis like you see in the ocean.
Actually, they are _exactly_ like some of the worst tsunamis you see in the ocean. Indeed, there is considerable concern about the potential for exactly such a landslide on the island of La Palma [wikipedia.org] from the collapse of the slopes of the volcano.
but if this happened on the coast of an ocean, the resulting 'wave' would be mere meters in height as it spread out.
Not really. The La Palma collapse is predicted to hit the western Canary islands with 400-600m high waves in 10 minutes, the coast of Africa with 50-100m high waves and within an hour, 15-20m waves in South America and Newfoundland after 3-6 hours and 25m waves in Florida after 9 hours so some significant non-local impacts. For reference the 2011 Japanese tsunamis _maximum_ wave height was the 40m you quoted and it generated waves of only 3-4m high at Hawaii, so the La Palma collapse is predicted to generate waves an order of magnitude higher.
Collapses like these may be a less frequent cause of tsunamis that earthquakes, and the smaller ones that are more frequent are only extremely destructive when they are locally bottled in by fjords and inlets but big landslides are the source of some of the largest and most destructive tsunamis ever known so the fact that they are much less frequent is a very good thing. In fact it is thought the the Storegga slide [wikipedia.org], a massive underwater landslide off the coast of Norway in ~6000BC wiped out about a quarter of the population of the UK at the time.
Re: Exactly Like the Worst Ocean Tsunamis (Score:2)
Tsunamis are not characterized by their number of deaths, but by the size of the wave. Saying a big wave is not like a big wave because in this case it didn't kill people is nonsense. It's a warning about what is coming and you are at the LA LA LA stage of denial.
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They are different. A splash as 40 bajillion tons of rock falling 1000 ft into water isn't the same as a thrust fault. Basic physics doesn't cause 600 Meter runups from a thrust fault like in Litaya Bay Alaska from a landslide.
A landslide wave doesn't have a wavelength of *miles* like a thrust fault tsunami. It might develop that as it spread across an ocean, but the impact as it comes in isn't the same thing as the entire crust pushing up miles of water along multiple miles of ocean.
High velocity small
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They are different. A splash as 40 bajillion tons of rock falling 1000 ft into water isn't the same as a thrust fault. Basic physics doesn't cause 600 Meter runups ...
Both are the same in that they are sudden displacements of a large volume of water. A thrust fault makes a small displacement over a large area and so acts as a large, diffuse source while a landslide may displace the same volume, or more for large ones like La Palma, but does so in a single concentrated point hence near the source the waves are insane but further from the source it makes literally no difference which happened.
The fact that a 100W LED bulb is a safe way to light a room but a 100W laser
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Nope, they are VERY different. Simply physics tells you that. A thrust fault tsunami will *never* directly cause a 600 meter wave (it obviously could trigger a landslide that would then do that). But direct effect simply will not happen.
The sources of the energy input are entirely different (punch vs mack truck) and the *initial* wave forms will similarly be very different.
La Palma waves, as they spread out crossing an ocean, may turn into a long flat 'tsunami' wave when it hits the US coast, but the
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Simply physics tells you that. A thrust fault tsunami will *never* directly cause a 600 meter wave
Physics most certainly does not tell you that. There is no law of physics that says a thrust fault can not generate waves of such magnitude if either the fault moved a sufficient large distance or the wave was focussed and concetrated by the surrounding land. Both are generated by the displacement of a large volume of water by the movement of land.
The reason that thrust faults generally do not do that is that they do not occur in inlets and fjords where the land would focus the wave and the fault fails
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Actually, they are _exactly_ like some of the worst tsunamis you see in the ocean.
The worst tsunami in this century was the 2004 tsunami in Indonesia, which killed over a hundred thousand people.
The wave in TFA killed zero people, injured zero people, and was a localized event in one fjord.
So it was nothing like a real tsunami.
Look, I get it. Global warming is a serious problem that we need to address. But shrill alarmism about these non-events is not helpful, even when you need 40 double-deck buses to measure them.
By that logic, if I shoot at someone with a .22 caliber weapon and hit them square in the head and kill them, then that makes the .22 a dangerous weapon, but if I shoot at them with a .45 caliber weapon and fail to hit them, then that makes the .45 a completely harmless weapon.
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So, your answer to the tree falling in a forest question is 'no'?
Interesting...
Worst = Biggest not Most Injured (Score:2)
So it was nothing like a real tsunami.
Everyone else except you measures tsunamis by the magnitude of the wave and the size of the impact not the number of people killed. We are lucky when such events are either localized to take place somewhere so remote that nobody is killed but it does not make the tsunami any smaller or less real.
Would you argue that the Tunguska event, caused by a meorite exploding, was not a real meteorite impact because although it was twice as energetic, unlike the Chelyabinsk event nobody was injured?
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Lituya Bay had runups of 600 METERS. That's not the same thing.
https://geology.com/records/bi... [geology.com]
A thrust fault tsunami will *never* do that.
I'm well familiar with the Canary Island La Palma coming disaster. My point being the 'initial' wave when that hits the water is a very different size and shape than when it comes ashore 1000 miles away.
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I'm well familiar with the Canary Island La Palma coming disaster. My point being the 'initial' wave when that hits the water is a very different size and shape than when it comes ashore 1000 miles away.
Then that is what you should have said. What you _actually_ said was "They aren't tsunamis like you see in the ocean." which is not true, they are exactly like some of the worst tsunamis that have been seen in the ocean. Yes they have a different, far more localized source than a thrust fault tsunami but fundamentally both are sources of massive water displacement resulting in tsunami waves. It's like a laser vs. a light bulb: a laser is far more intense and coherent than a light bulb but that does not mea
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and you sir need to work on your comprehension as I specifically said they are like 'splashes'. Thrust fault tsunamis do not SPLASH on initial creation.
Good Day. shame we can't block here as you continue to misconstrue basic logic.
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I specifically said they are like 'splashes'. Thrust fault tsunamis do not SPLASH on initial creation.
My comprehension is fine the problem is that your logic, assumptions and facts are all wrong. First, not all things that we call ocean tsunamis start from a thrust fault. Second not all landslide tsunamis start with a splash. The example I gave of the underwater landslide off the cost of Norway that wiped out a quarter of the population of Britain around 6000BC did not start with a "splash". Third, a long way from the source if makes no significant difference whether the source was a thrust fault or a land
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Again, basic physics seem to elude you.
There will be no 600m wave from a thrust fault...or if you want, an underwater landslide. Because the input energy isn't above the water level. The only time you get 600 METER high waves is splashing from a high height above the water landslide hitting the water.
Feel free to provide examples of this if you can. But I'm quite sure you can't because physics is a harsh mistress as they say.
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Even small waves are quite dangerous. Sadly I can't find the video now, but NHK broadcast some demonstrations of what a 30cm tsunami wave is like if it hits you. It was impossible to stand up, and the test subject was quickly swept away. Cars and the like would be floated and moved, buildings could be collapsed by it.
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There was an instance a decade or so ago in Indonesia that was pretty much like this, except that it wasn't without damage or injury. How dangerous the things are depends on where they happen. They don't happen very often, so saying global warming makes them more likely still doesn't make them very likely.
It's a real danger if you live near a coast, but it's not one of the dangers you're more likely to encounter.
Great (Score:2)
Luckily no one was hurt, though a military base was obliterated.
Great. If only we can get rid of all military bases.
No 200m high Tsunami. (Score:1)
The water crept 200m uphill. The actual Tsunami was more likely 10-20m high.
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The water crept 200m uphill. The actual Tsunami was more likely 10-20m high.
20-meter waves don't creep up 200-meter hills.
That's nonsense.
Re: No 200m high Tsunami. (Score:4, Informative)
40 double-decker buses (Score:4, Funny)
Whats that in Libraries of Congress?
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Whats that in Libraries of Congress?
TFA uses double-deck buses as units of height.
A "Library of Congress" is normally used as a unit of information, as in gigabytes or whatever.
If you want to use a LOC as a unit of height, the logical conversion would be 59 meters, which is the height of the dome over the main reading room in the Thomas Jefferson Building [wikipedia.org] which currently houses the LOC.
200 meters = 40 DDB = 3.39 LOC
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What about Empire State Buildings? It's about 1/2 Empire State Building.
40 double decker buses (Score:3)
Re: 40 double decker buses (Score:3)
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For the record its 0.000000667128 light seconds.
Re: 40 double decker buses (Score:2)