Scottish avalanche figure surpasses last season's

Lumps of a collapsed cornice, among the causes of avalanches, in Lochaber

The number of avalanches recorded in the Scottish mountains so far this winter has surpassed the total for the whole of the last one.

The Scottish Avalanche Information Service (SAIS) records the snow slides during its forecasting seasons, which run from December to April.

The last forecasting season, 2016-17, involved the service's lowest number of recorded avalanches in almost 10 years.

There were 90 avalanches then, and 94 so far this season.

The number of avalanches recorded so far this season is a provisional figure at this stage. Confirmation of the final tally will be released later in the year.

Debris from a deliberately triggered avalanche during a training exercise in the Cairngorms

Avalanches can be occur naturally for a variety of reasons, including by overhanging ledges of snow called cornices collapsing and falling down on to steep snow-covered mountainsides.

Human activity such as skiing, walking and climbing can also trigger avalanches.

Again, cornices present one of the greatest risks, with people venturing out on to the ledges believing it be snow-covered solid ground.

Debris from naturally occurring avalanches in Coire nan Gall

Unlike last winter, this 2017-18 winter has seen heavy snowfalls and much longer periods of freezing temperatures.

The conditions have resulted in a busy spells for Scotland's mountain rescue teams, with Lochaber and Cairngorm MRTs among the teams being called out the most frequently.

This winter, mountain rescue and avalanche forecast teams have reported regularly experiencing "full-on Scottish winter conditions", which can include blizzards, white-out conditions and gale force winds.

An SAIS forecaster on a trip in the Southern Cairngorms at the weekend

In 2009-10, one of SAIS' most active seasons for avalanches, snow slides affected a railway line and a trunk road.

The West Highland Line between Tyndrum and Bridge of Orchy in Argyll was closed for almost two weeks over late February into early March after it was blocked by four avalanches from the slopes of Beinn Odhar.

Network Rail said its workers removed more than 15,000 cubic metres of snow before the line could be reopened.

Avalanches also affected motorists on sections of the A9.

Previous avalanche numbers

• 2015-16 - 207

• 2014-15 - 305

• 2013-14 - 350

• 2012-13 - 129

• 2011-12 - 154

• 2010-11 - 178

• 2009-10 - 220

Mountain hares braving wind and drifting snow in the Cairngorms