Highland hazards

There are dangers lurking in the highlands of western Norway. Towering over beautiful fjords is a 600-metre long crack in a steep mountainside. The crack worries researchers, not least in the tourist village of Geiranger.

11. apr 2007 23:00

Åknesremna, Møre og Romsdal. FOTO: ÅKNES/TAFJORD-PROSJEKTET, NYSGJERRIGPER 2-07Åknesremna is a crack in the mountain located 800 metres above sea level in Møre & Romsdal County. It is widening by three to 10 centimetres each year. Researchers know that this can only mean one thing: a landslide is imminent. PHOTO: ÅKNES/TAFJORD-PROSJEKTET Named Åknesremna (the Åknes Rift), the crack is located at an elevation of about 800 metres above sea level in Møre & Romsdal County. It is widening by three to 10 centimetres each year. Researchers know that this can only mean one thing: a landslide is imminent - and this won't be the first time.

Tidal waves in Norway

Norway has experienced several huge tidal waves along the coastline and in the fjords. The best known disaster is the Tafjord slide that occurred in 1934. Parts of the mountainside simply dropped off, causing a 64-metre high tidal wave to wash about 200 metres inland. It completely wiped out the villages of Tafjord and Fjøra in Møre & Romsdal County.

Can happen again

Researchers are painfully aware that disasters like that can happen again. Consequently, they want to do everything they can to ensure the earliest possible warnings as there will be no time to spare. They have calculated that if Flodbølge, tsunami, Tafjord. FOTO: SCANPIX, NYSGJERRIGPER 2-07Parts of the mountainside simply dropped off, causing a 64-metre high tidal wave to wash about 200 metres inland. The tidal wave made kindling wood out of houses in Tafjord. PHOTO: SCANPIX the Åknesremna were to break off, the tidal wave would reach Geiranger just ten minutes later! In other words, every second will count.

Monitoring

A state-of-the-art surveillance system records the tiniest little movement in the mountain. Using lasers, radar and GPS, the mountain is studied carefully. There is even a weather station that provides continuous weather reports from the area. It is important to keep an eye on the wind, precipitation and temperature.

Unfortunately, these steep mountainsides are not very easily accessible. For that reason, eight helicopter pads have been built in the mountain highlands. Helicopters convey people and equipment to where they are needed. There are also two bunkers where the researchers have provisions, electricity and sleeping accommodations.

Automatic early warning

It is particularly important to keep an eye on the systems of cracks, or fractures as they are called. From experience, researchers know that the level of activity increases as a landslide becomes imminent. In a manner of speaking, when the mountain gets very active, it sends out its own early warning. By constant monitoring, researchers therefore believe that they can predict a slide least one day in advance.

Flodbølge, tsunami, Tafjord, faksimile. FOTO: SCANPIX, NYSGJERRIGPER 2-07The daily newspaper Aftenposten covered about the tidal wave that struck Tafjord in 1934. PHOTO: SCANPIX Calculating waves

Surveying and monitoring are not limited to the mountainsides. To be prepared as well as possible in the event of a landslide, it is also important know a great deal about the seabed in the fjords. Such knowledge makes it possible to calculate how high the waves can be, and how quickly they will travel up the fjord. By mapping the shore zone, scientists can figure out how far waves will wash up on shore.

Breaking the waves

Scientists have vast amounts of data from readings and from disasters as a result of past slides and floods. Computers allow them to use the data to simulate what would happen if there were to be a landslide. They can predict where the tidal wave will peak, and where it will be most dangerous.

This information is especially important for municipalities, so that they can prevent building and construction, etc., in dangerous locations. This enables them to avoid the type of disasters that have struck this and other areas so many times before.

Translated by Linda Sivesind

*Published in 'Nysgjerrigper' no. 2/07*