23/9/2014 Fracturing of ancient bedrock surfaces during an extremely hot summer

NOAA reports that August 2014 was the hottest since records began. Long periods of exceptionally high temperatures in California and Finland this summer have been associated with the formation of large ‘exfoliation’ or ‘sheeting’ fractures in bedrock surfaces that may have remained largely unchanged since the last ice age. Recent videos show sharp fractures forming along the edge of thin (<1 m) bedrock sheets several meters across, before the rock surface appears to jump and buckle in the hot summer sun.