In mid-January 2013, a large landslide rumbled down the slopes of one of New Zealand’s tallest mountains. The massive slide of rock, ice, and snow on Mount Dixon occurred around 2:30 p.m. on January 21. The mountain lies within Aoraki/Mount Cook National Park and is part of the range dubbed the “Southern Alps.” The slide is believed to be the largest in the area since 1991.
The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured these two views of the area around Mount Dixon and Mount Cook/Aoraki. The top image was acquired on February 5, 2013, two weeks after the landslide. For perspective, the second image shows the same area roughly a year earlier, on March 13, 2012.
According to news reports and preliminary analysis, rock and ice debris fell as much as 450 to 500 meters (1,500 to 1,600 feet) down a near vertical face on the southern flank of Mount Dixon. Debris continued to slide down Hochstetter glacier into the Grand Plateau, spreading out over 3 kilometers (2 miles) and cascading down another 300 meters (1,000 feet) in elevation (800 meters total, or a half mile).
Landslide expert and Durham University professor David Petley wrote: “This is a very impressive landslide, with a large fall height and long runout distance, although as far as I can see there is nothing surprising about its behaviour.”
At the time of the avalanche, thirteen people were camped out in the Plateau Hut. Neil Wiltshire, a climber and occupant of the cabin, caught the slide on video. To view it, click here. For a collection of still images from the avalanche site, click here.Petley also did some further analysis of the landslide here.