Tsunami from earthquakes or glacier calving?

[Espen]

Happened last night:

http://knr.gl/da/nyheder/det-ved-vi

[Espen]

Video from the site:

http://knr.gl/da/nyheder/jordsk%C3%A6lv-skyld-i-oversv%C3%B8mmelser

[Jim Hunt]

I can find no record of a recent earthquake in the vicinity. Can anybody else?

[sesyf]

Radio news here told that a 4.0 earthquake would have taken place...

[Jim Hunt]

There's no sign of it on this list though:

https://www.emsc-csem.org/Earthquake/world/M4/

[doogi]

I can find no record of a recent earthquake in the vicinity. Can anybody else?

I belive this might be the one:

http://www.earthquakescanada.nrcan.gc.ca/index-en.php?CHIS_SZ=arctic
http://www.earthquakescanada.nrcan.gc.ca/recent/maps-cartes/index-en.php?tpl_region=arctic#events
2017/06/09    09:32:49    73.22    -72.70    18.0    3.5    No    183 km E from Pond Inlet,NU

Nevermind, appears to be wrong date

[Andreas Muenchow]

Google translate from the Danish news that Epsen linked to

"GEUS states in an email KNR that an earthquake has a magnitude of 4.1 approx. 28 kilometers north of Nuugaatsiaq last night at 23 o'clock, and it probably is what triggered an earthquake and created the great waves.

The police still call on people in the fjord system around Uummannaq to stay away from the coastal areas as aftershocks can not be ruled out."

Checking the tide gauge at Thule next to see, if the waves are seen there ...

EDIT: No tsunami signal at Thule http://www.ioc-sealevelmonitoring.org/station.php?code=thul

EDIT-2: Large landslides did occur in the Disko Bay region before and caused tsunamis. A 2000 tsunami was as observed and published in https://www.degruyter.com/downloadpdf/j/popore.2015.36.issue-1/popore-2015-0005/popore-2015-0005.pdf which perhaps explains what happened last night. Lets hope that the 4 people still missing are alive and will be found soon.

[doogi]

GEUS latest statement is that they're not sure whether it's an earthquake or an landslide that caused the tsunami.
GEUS measuring station in  Nuugaatsiaq registered the event at about 21.40 and the tsunami hit the island 8 minutes later.

http://knr.gl/da/nyheder/usikkert-om-det-er-jordsk%C3%A6lv-eller-jordskred]
[url]http://knr.gl/da/nyheder/usikkert-om-det-er-jordsk%C3%A6lv-eller-jordskred[/url]

[Adam Ash]

RT version, with video
https://www.rt.com/news/392937-greenland-tsunami-flooding-evacuation/

[wili]

Any indication of wave height at landfall?

This discussion of the relation of calving and seismic activity may end up to prove relevant here:

https://www.washingtonpost.com/news/energy-environment/wp/2015/06/25/giant-earthquakes-are-shaking-greenland-and-scientists-just-figured-out-the-disturbing-reason-why/?utm_term=.4986ff88d888

(Thanks to vox at POForums)

[Phil.]

There has been tsunamis recorded from glacier calving before here's a paper on one:
http://www.the-cryosphere.net/10/995/2016/tc-10-995-2016.pdf

[jai mitchell]

I woke from a dream this morning where I was standing in a town across from a very large body of water with a partially snow-covered mountain on the other side that, due to an earthquake, collapsed into the ocean (lake?).  A very large Tsunami was coming and we had to run to high ground (woke up before the end but I don't think we made it since the whole mountain (about 2,500 meters high) collapsed into the water.

not that this means anything at all but I have my suspicions. . .

[nicibiene]

I always look this earthquake map, Svalbard was hit too. Connected? https://earthquakes.volcanodiscovery.com/

Jai, once I dreamed our steep hill behind the house (a mining halde, that creates streams in our garden when undermined by flooding rains or rapid snowmelt) starts sliding due to heavy rains...  Heard a week ago that there was indeed a landslide once, some years ago...not a pleasant dream. 

[nukefix]

There's no way a 4.0 earthquake can start a tsunami. It might trigger a landslide or huge calving though. I'd look through satellite imagery including Sentinel-1 and try to identify what has changed.

[johnm33]

The ground was very wet in the vid., duckboards and all, there was cloud cover the whole previous day, did it rain in the mountains? Signs of rapid flow here http://www.polarview.aq/images/106_S1jpgsmall/201706/S1A_EW_GRDM_1SDH_20170618T104039_8E6A_N_1.jpg When things clear we'll see what happened, hope it wasn't a 'permafrost' mountain collapsing.

[doogi]

The landslide causing the tsunami is now located at Karrat icefjord.


http://knr.gl/da/nyheder/fjeldskred-i-karrat-isfjorden-skyld-i-flodb%C3%B8lge

[Urbanus Simpliticus]

 A minor Stochastic event affiliated with the permafrost condition.
Only displacement creates tsunamis
It's not a seismically active area, so the sensors sensed the actual collapse.
It's quite conceivable that some calving tsunamis will run up a neighboring fiords. Possibly triggering other events.
The fiord ice appears to have been swamped in the vicinity.
 The local tide cycle has a peak to trough of 2.5 meters which is impressive for the location, and the houses are of course situated for the max tide.
Thanks for the local tide level posts.

The landslide causing the tsunami is now located at Karrat icefjord.


http://knr.gl/da/nyheder/fjeldskred-i-karrat-isfjorden-skyld-i-flodb%C3%B8lge

[TerryM]

This is going to have shaken off a lot of fast ice. I wonder if local glacier's will speed up?


Terry

[johnm33]

before and after 5  19

[georged]

before and after 5  19

Look at how much snow cover has been lost. Impressive.

[Hans]

Look at how much snow cover has been lost. Impressive.

I assume just melted in 14 days time; it's summer . Not due to land slide.

But: Please help me to spot the landslide in these images. I do not see a difference..

[ms]

More details about the land slide and the risk of another slide here:
https://ing.dk/artikel/geus-overhaengende-risiko-nyt-fjeldskred-groenland-200633
(in danish)

[Reallybigbunny]

Wow! Check out the link below.

http://www.stuff.co.nz/world/europe/93908659/pictures-of-submerged-houses-reveal-devastation-of-greenland-tsunami

[FishOutofWater]

Large landslides causing destructive tsunamis are becoming more frequent in Alaska as the climate warms. The same processes of meltwater and permafrost degradation weakening steep slopes will affect Greenland and the CAA.

[solartim27]

Likely to be more in the near future (this is full translated text, minus links to other articles)

http://knr.gl/da/nyheder/endnu-et-fjeldskred-truer

Apparently there is not just one - but two - areas at risk of landslide at Nuugaatsiaq and Illorsuit.

It assesses geologists from GEUS with Asiaq, writes Sermitsiaq.AG.

The newspaper is the new and novel area about five kilometers west of the mountain, which slithered down and triggered tsunami for just over two weeks ago.

This is not to say how large an area is involved.

- It is more diffuse, and therefore we can not say very precisely how large the area is. But immediately it looks a little bigger than the piece that fell, says deputy director of GEUS Flemming Getreuer Christiansen to Sermitsiaq.AG.

[Downpuppy]

Since there's no Stupid Questions thread in the Greenland forum : I've read that the weight of ice has pushed down the land level. Are there any studies on what happens as the ice weight is reduced? It's easy to imagine earthquakes, or even a positive feedback where rising land dumps the glaciers into the North Atlantic at a faster & faster rate.

Anyhow, just a (hopefully very unlikely) Doomsday scenario for today.

[Sailaway]

The adjustments from the removal of thick ice from the land takes 1000's of years. For example parts of the UK are still rising from that effect. The shorter term effects of climate change on land forms are more likely to be associate with the loss of the permafrost with associated land slips. In this case there was a small quake in the region which may have acted in combination. The "Tsunami" in the thread was (in geological term) small and localized - in human terms far greater.

[sqwazw]

Are there any studies on what happens as the ice weight is reduced?

Google: "Isostatic rebound"

Northern continental areas that were previously glaciated have good long baseline geodetic GPS surveys of this effect and many nice maps. It runs from a couple of mm's to cm's per year uplift due to the current post glacial rebound. The earths rocky crust can be thought of as "a warm plastic" and gravity induced stress and strains deform it macroscopically over the course of thousands of years after the TeraTonnes of ice have been melted away.

[Downpuppy]

Yes, I've seen that we're in the late stages of a rebound from the last ice age, although I'm in a coastal area (New England) that's sinking. Most of the articles talk about an early, faster stage, and a slow fill in. There's references to earthquakes, volcanoes, and Iceland rising over an inch a year.

In any event, it doesn't sound like something really violent will happen soon.

[Steven]

There is more information about last month's landslide and tsunami at this link:

http://www.nature.com/news/huge-landslide-triggered-rare-greenland-mega-tsunami-1.22374

A research team that visited the site earlier this month found that a large volume of rock had plunged — probably spontaneously — from one of the steep sides of the fjord into the water 1,000 metres below, and shattered chunks of a glacier. That disturbance pushed water levels up by more than 90 metres along the coastline on the same side as the slide. And although the tsunami dissipated quickly as it crossed the deep, six-kilometre-wide fjord, it still had enough energy to send water 50 metres up the hillside opposite. The team also measured an increase in water levels of about 10 metres on shorelines 30 kilometres away.

...

Researchers have noted another potentially imminent landslide in the Karrat Fjord, says Fritz, where a slow trickle of rocks could turn into abrupt slide. Residents of three villages in the region have been permanently evacuated to the nearby town of Uummannaq

[Forest Dweller]

This one went practically unnoticed recently:

http://blogs.ei.columbia.edu/2016/07/02/massive-landslide-detected-in-glacier-bays-fragile-mountains/

600 feet runup!

Carana mentions another Greenland quake causing methane release:

http://arctic-news.blogspot.nl/2017/05/earthquake-east-of-greenland-triggers-methane-releases.html