30 January 2014

Nord-Statland: A landslide-induced tsunami on Wednesday that caused serious damage

Posted by dr-dave

The Nord-Statland tsunami

At about 4:30 on Wednesday afternoon, the small Norwegian village of Nord-Statland was struck by a localised tsunami, which reports have suggested was as high as 15 m (though this looks unlikely).  The village is located in Nord-Trøndelag, as shown below in Google Earth:

Nord-Statland

A close-up of the village looks like this:

Nord-Statland

The damage to the village is very serious.  This is a pair of before and after images from nrk.no:

Nord-Statland

http://www.nrk.no/trondelag/_-kunne-blitt-en-katastrofe-1.11507175

After:

Nord-Statland

http://www.nrk.no/trondelag/_-kunne-blitt-en-katastrofe-1.11507175

Whilst this is the area further around the bay (from this gallery of images):

Nord-Statland

http://www.nrk.no/trondelag/to-ars-produksjon-kan-vaere-tapt-1.11507388

Finally, this is image, from http://www.adressa.no/, shows the immediate aftermath of the tsunami:

Nord-Statland

http://www.adressa.no/nyheter/nordtrondelag/article9040275.ece

The cause of the Nord-Statland tsunami

The highly localised impacts of this tsunami, and the lack of sesmicity, suggest that this was a landslide-induced event.  Reports (in Norwegian) suggest that there was a landslide on the other side of the fjord.  However, according to this report, the landslide scar is too small to have caused the observed tsunami, which suggests that the cause was a submarine landslide within the fjord.  This report (also in Norwegian) suggests that the cause may have been new houses and a marina under construction close to the village – as far as I can tell it is describing these houses:

Nord-Statland

http://www.nrk.no/trondelag/flodbolgen-kan-skyldes-fyllmasse-1.11507332

..

The suggestion is that the disposal of spoil from these works triggered an underwater slide that in turn generated the tsunami.  Whatever the cause, the upshot is that 57 people have been evacuated, but fortunately no-one was killed.  The damage to this small village looks to be very serious, including a million fish in a smolt plant.  The effects could have been much worse if the landslide had occurred in the summer.