RAPID: Pyroclastic Surge Dynamics in the 2010 Merapi Eruption

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

This is a RAPID award to investigate the dynamics of pyroclastic surge deposits created by the catastrophic 2010 eruption of Merapi volcano, Indonesia. Pyroclastic flows and surges cause most casualties in volcanic eruptions but understanding of surge processes is lagging due to the paucity of major events such as the one displayed by Merapi during its recent eruption phase. This investigator and his team have developed a statistically constrained procedure for lava dome-collapse type pyroclastic flows to estimate areas of inundation following an active event. Dynamic behavior of associated surges can be included by consideration of the physics of surge flow, mass flux and air entrainment, and local topography. The method has been applied to several volcano crises, notably the 2006 eruption of Merapi and 2007 and 2010 crises at Montserrat. It is also being used for hazards evaluations at other locations worldwide, but while of proven utility it is restricted to a particular type of flow process. The recent Oct-Nov 2010 eruption at Merapi offers a rare "Once-in-a-Century" opportunity to extend and constrain physics-based modeling to column-collapse type pyroclastic flows with associated ash-cloud surges. This Merapi eruption started in its traditional dome-collapse mode but developed into a major VEI~4 explosive eruption, the largest eruption there since (at least) 1872. The likelihood of an explosive eruption on this scale was forecast by the PI and his team, and now that it has occurred it is incumbent to maximize the scientific and other impacts. It is proposed to further refine the surge model for Merapi that would carry over to other flow modeling methods such as Titan2D which inadequately address the surge issue. The proposed study of the surges addresses a target of opportunity and needs to be carried out soon because the thin deposits are perishable and key information would be lost. Thus a RAPID award is the most appropriate mechanism for supporting the proposed work. The broader impacts are many and include as beneficiaries of this research organizations that foster risk mitigation planning and crisis response, such as volcano observatories worldwide, academic advisors to crises, and those such as the World Organization of Volcano Observatories (WOVO) that often aid crisis responses generally. Ultimately it is the often-large populations living on the flanks of dangerous volcanoes who may benefit most. Findings are expected to be disseminated to academics and practitioners through rapid communication at international and national scientific meetings and workshops, lectures at academic and government institutions and local observatories, abstracts of presentations in published works, and articles in peer-reviewed high-profile scientific journals, and electronic media.