The steep mountain sides and deposits in the valleys and the fjord show that earth and stone that has moved by gravity, such as landslides and avalanches, are very important to the formation of this rugged alpine landscape.
The area represents one of the most hazardous regions for avalanches and landslides. Annual snow avalanches on the steep sides of valleys and fjords represent a significant hazard, and an evacuation plan is needed in the village of Geiranger.
Along fjords and valleys, the fractured and faulted gneisses are unstable and prone to rock avalanches and rock falls. There are numerous occurrences of well-defined slide scars and avalanche tracks ending in cones or slide aprons entering the fjords or along the lower valley slopes.
These features represent some of the world's most spectacular features of rock-slide deposits in fjord settings. On several occasions in historical times, rock avalanches plunging deeply into the fjords have generated large tsunamis that have destroyed villages and killed people.
The Tafjord disaster
The last catastrophe was the Tafjord disaster in 1934, when approximately 3 million cubic metres of rock fell into the fjord and created a wave up to 62 metres high. The flood wave was about 10–15 metres high when it had travelled 8–10 km out along the fjord, after it had crushed three villages and killed 41 people. The small community of Fjørå was completely destroyed by the wave, and 17 people had died. The several hundred-metre high slide scar still looks fresh and stands out as a vegetation-free surface compared to the mountain slopes nearby.
The deposits of many similar or larger avalanches are present along the fjord basins, confirming the wildness and dynamics of such a landscape.
Large avalanches are annual events in the Geirangerfjord area.
Where: between Humlung and Gjørva, Fonnjanesfonna (the biggest)
Where: From Geitfonnegga
Where: Just above Matvik (the most dangerous)
Geology and landforms
- How the glaciers formed the landscape
- A living landscape – The Quaternary (1.8–0 million years)
- Landslides and Avalanches
- Rivers and waterfalls
- From open ocean to narrow fjord
- A history written in stone (1600–100 million years)
- New rising – tertiary (65–2.5 million years)
- The geology of the bedrock is the key to history