31 May 2009

Large fatal landslide in Papua New Guinea

Posted by Dave Petley

On 25th May there was a large landslide in Papua New Guinea that reportedly killed 19 people. Reports about this event have been rather hard to come by, so I went searching through the Papua New Guinea only newspaper sites. The most dramatic image is this one, from The National:

It is clear that this is very large landslide (see below). The dynamics are fascinating as the source area appears to be very small. The slide has then scoured out what appears to be colluvium deposits from within a channel on the upper part of the hillside, before transitioning into a large -scale, highly energetic flow.

I also came across these images and this report on the pages of the Papua New Guinea Post Courier.

This image shows the track of the landslide

This image reportedly shows the landslide deposit.

The report (shortened here) states that:
A family is counting its luck after all its members survived a massive landslide that killed 19 of their relatives between
the gorges of Firangka in the Sialum district of Morobe Province. The family of five survived by metres when the landslide swept down the mountainside and engulfed six houses, missing their hamlet in Zongefifi in the early hours of Monday…Locals retrieved three bodies, two male and one female while the other 16 bodies were still buried. The landslide started from the top of the mountain, slid down the gorge for about half a kilometre with debris strewn over
200 metres wide before dropping down the steep terrain.

Mr Gamato [deputy administrator] said the landslide was caused by water underneath the coronus limestone which had built up and caused the ground to become unstable, causing a massive slip. He also warned that the months of May, June and July were a time of continuous rainfall in the province and those travelling by sea, living along river banks and under mountainous terrains should take extra precaution because of the rain in the province in recent weeks.”