10 February 2012

Comparing the response to the Tumbi Quarry and Philippines earthquake landslides

Posted by Dave Petley

One of the remarkable facts about the Tumbi Quarry landslide in Papua New Guinea is that there still appears to be considerable doubt about the numbers of people lost.  Reports still vaguely mention an estimated number of 25 people, and possibly as many as 60.  Even the unimpressive National Disaster Centre report said only: “At this stage, there is no exact figure of the population affected; No bodies have been recovered.”  Given that there is very little likelihood of being able to recover the bodies from such a vast landslide, it is surprising that there are no reports of detailed work to ascertain who has been killed.  One can only hope that this is happening in the background.

In remarkable contrast, remarkably good data is available from the Philippines, despite the obvious chaos of the earthquake impacts.  The latest NDRRMC report gives lots of information about the impacts of the earthquake.  Most impressive is the care that has gone into compiling victim statistics.  This data shows that of 34 confirmed fatalities, 20 occurred as a result of landslides.  There are 71 people reported to be missing, all thought to be buried under landslides.  If these statistics are a true reflection of losses, it will mean that of 105 fatalities, 91 will have been caused by landslides.

Seismologists often say that it is not earthquakes that kill people, it is buildings.  Yet again that has been shown not to be correct, but investment in understanding and mitigating earthquake induced landslides remains pitiful.

Some pictures are now emerging of the landslides.  International Business Times has this one of the landslide in La Libertad:



Quezon.ph has this rather helpful image of landslides on La Libertad mountain.  Note that most of the landslides seem to have initiated at the ridge top, which is a characteristic sign of earthquake induced landslides:



Even more remarkable is this helicopter image of the landslide at Guihulngan, from CTV: