Thread by @Rollalex

On this day in 1934, the inhabitants of Tafjord and Fjora, Norway🇳🇴, have been awakened by a strange sound in the night. A few minutes later, a huge tsunami wave destroyed houses and boats and killed 40 people. Most of them will never be found. ⬇️

#OTD #tsunami #landslide

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The culprit ? A rock avalanche of about 3 million m3, which the scar is still visible (see orange line). The generated waves (at least three) reached an altitude of 62 m above sea level (more than two blue whales 🐋!!).

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I let you see the damages by yourselves with these before and after pictures taken in Fjora. The source is a website with incredible testimonies.

Feel the vibe: "Dead cats, goats and lambs are found in the bushes" 🐈🐐🐑

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Now let's do the maths.

The velocity of a tsunami wave is given by the square root of the gravitational acceleration and the depth:
v=sqrt(g*h)

With an average depth of 150 m towards Tafjord:
v=40 m/s or 144 km/h -> a car on the highway !

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Although far from seismic tsunami risk, Norway is highly exposed to the landslide tsunami risk because of its numerous fjords. That's why we need to study them !

Stay tuned for more landslide tsunamis 🙂

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OMG I forgot the link to the website 😱🤦🏻‍♂️:

bolgen.tight.no

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