Tuesday 17 December 2013

Two killed by Utah rockfall.

Two people were killed when their house was destroyed during a rockfall in the town of Rockville in Washington County, Utah, at about 5.00 pm local time on Thursday 12 December 2013 (midnight between Thursday 12 and Friday 13 December, GMT. They have been named as Maureen Morris (65) and Jeff Elsey (58). The wooden house, valued at US$380 000 is understood to have been destroyed instantly when struck by boulders with a combined weight of several hundred tonnes.

The remains of the Rockville, Utah home destroyed by a rockfall on 12 December 2013. AP.

Rockville has suffered a series of major rockfalls in recent years, causing severe damage to a number of properties, but this is the first fatal incident for some time. The town sits at the base of the southern slope of the Rockville Bench, where the rocks of the Shinarump Conglomerate overlie the softer shales, siltstones and sandstones of the Moenkopi Formation. The easily eroded Moenkopi deposits form an unstable slope, subject to erosion by rainfall, freezing and thawing and the occasional Earthquake. Above this the more solid Shinarump rocks form a blocky cliff, from which large boulders occasionally break away as they are undermined, tumbling down the slope onto the town bellow.

A characteristic path profile for rock falls sourced from Rockville Bench. Knudsen (2011).

The approximate location of the Rockville landslide. Google Maps.

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