Galtur Avalanche

OVERVIEW

CAUSES

RESPONSES

MANAGEMENT

50 metres (160 ft) high and traveling at 290 kilometres per hour (180 mph)

powder avalanche

February 1999 in the Alpine village of Galtur, Austria

57 deaths

worst Alpine avalanche in 40 years

Further snow storms caused by cooled air from the Tropics and cold Arctic air, created a large snow pack on the mountains above Galtur.

Freeze thaw conditions created a weak layer on top of the existing snow layer. Further snow was then deposited on top



Northwest winds also piled the snow the increasing depths
This put a lot of shear stress on the weak layer underneath the new snow pack. Inevitably, the weak layer failed and caused the powerful powder avalanche to crash down the mountainside, picking up more snow and speed as it went. During the event, there was also the presence of winds of 120km/hour, causing this layer of snow to at a high speed.

January 1999: a series of storms occurred, bringing 4 meters of fine snow that formed a huge snowpack on the mountains above Galtur

Galtur was hazard zoned, with the risk levels being categorized into three colors
However, the green zone was the area that was the worst hit.

→ Red zones: highly vulnerable to avalanches (no development permitted in these areas)
→ Yellow zones: moderate risk to avalanches (development is allowed but structures must be built to resist avalanches)
→ Green zones: avalanche-safe (development is permitted with no reinforcement required)

The hazard zoning is based nearly entirely on the historical record, and there was no evidence of avalanches traveling so far on this track in the past.

However, the green zone was the area that was the worst hit.

IMPACTS

Immediate

Long-term

Socio-economic

Environmental

The avalanche caused slope instability, which could a contributing factor to trigger future avalanches


Melted ice that could cause floods

Public infrastructure, including 16 buildings were destroyed/severely damaged

Negative impacts on the local tourism industry

5000 people were evacuated

Tension rises between authorities and affected families

31 people died

Ski resorts were closed in the region, costing the industry 5 million pounds for each day they were closed

Negative headlines in the press of the event damaged the reputation of the Galtur village, which subsequently leads to the decline in popularity as a major tourist destination

The US, Germany, Switzerland and France sent aircraft, sniffer dogs, medical supplies, food & water to support evacuation

The rescuers saved 26 people in 24 hours

Adverse weather conditions (poor visibility) continually hampered the rescue operations



Destroyed transport infrastructure meant that a response by road was not possible for 3 days → rescue operation was only feasible by air (however, crew had to fly below tree line in order to not create an additional avalanche risk)





Since the disaster, there has been renewed efforts to improve avalanche knowledge to increase the accuracy the mapping of hazard zones.

Austria had developed a range of avalanche coping means

More avalanche-resistant buildings

A 980 feet avalanche dam built to protect the village

Steel fences constructed on all mountainsides above the village to break up the impact of the avalanche.

Afforestation

Extension of hazard zones

Scientists have considered the effects of land use and climate change to further improve the accuracy of the predictions.