We can imagine few things scarier than this.

However planned you are for unfortunate eventualities in the mountains - there's very little you can do to anticipate a seemingly stable field of snow suddenly opening up beneath you. But that's exactly what Bjorn Hofmann faced up in Valais, Switzerland last season.

There's very little you can do to anticipate a seemingly stable field of snow suddenly opening up beneath you

Of course there have been previous incidents which make the risks of glacial riding very clear - but it doesn't deduct from the shock factor when an unassuming spot disappears into the mountain itself.

Fortunately it seems that the group were aware of the dangers - and appear to have been riding with harnesses and crevasse rescue equipment as a precaution. Either way, that's not the kind of snowy drop you're looking for on a bluebird day in the Swiss alps.