Before we get started, sorry about the slow trickle of posts lately - it is the mid-semester crunch where everyone is busy, sick or both. Hopefully, this will all begin to clear up soon. I mentioned via Twitter over the weekend that after a M6.7 earthquake in the Philippines, three 50-meter cracks appeared near the crater area of Kanlaon on Negros. The volcano hasn't erupted since 2006 but after this earthquake (that also triggered a landslide), PHIVOLCS officials wanted to check to make sure that new signs of a potential eruption hadn't appeared. So far, helicopter availability has made it difficult to assess the entire volcano, but Antonia Bornas, chief of the PHIVOLCS Volcano Monitoring and Eruption Prediction Division, has said that these new cracks will not trigger an eruption of Kanlaon. However, they have declared the volcano off-limits to climbers until the cracks are fully assess and the risk of additional landslides subsides. If Kanlaon were to start erupting again, we should expect fairly small explosive eruptions that could potentially generate lahars (mudflows) if the conditions are right (i.e., precipitation). The volcano has erupted frequently in historic times (going back to 1866). However, the Global Volcanism Program does mention a 33-km long avalanche deposit from Kanlaon - the largest in the Philippines. These volcanic avalanches don't necessarily need to occur when the volcano is active - which makes any cracks appearing on the edifice of Kanlaon all that much more worrisome.
Image: Kanlaon in the Philippines - Joselito Tagarao / Flickr