Kinematic characteristics of pyroclastic density currents at Merapi and controls on their avulsion from natural and engineered channels

Abstract

Research Article| May 01, 2011 Kinematic characteristics of pyroclastic density currents at Merapi and controls on their avulsion from natural and engineered channels Gert Lube; Gert Lube † 1Volcanic Risk Solutions, Institute of Natural Resources, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand †E-mail: g.lube@massey.ac.nz Search for other works by this author on: GSW Google Scholar Shane J. Cronin; Shane J. Cronin 1Volcanic Risk Solutions, Institute of Natural Resources, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand Search for other works by this author on: GSW Google Scholar Jean-Claude Thouret; Jean-Claude Thouret 2Laboratoire Magmas et Volcans, Université Blaise Pascal, Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) et Institut de recherche pour le developpement (IRD), 5 rue Kessler, 63038 Clermont-Ferrand cedex, France Search for other works by this author on: GSW Google Scholar Surono Surono 3Center of Volcanology and Geologic Hazard Mitigation (CVGHM), Jalan Diponogero, Bandung 40122, Java, Indonesia Search for other works by this author on: GSW Google Scholar GSA Bulletin (2011) 123 (5-6): 1127–1140. https://doi.org/10.1130/B30244.1 Article history received: 05 Jan 2010 rev-recd: 31 Aug 2010 accepted: 18 Sep 2010 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Gert Lube, Shane J. Cronin, Jean-Claude Thouret, Surono; Kinematic characteristics of pyroclastic density currents at Merapi and controls on their avulsion from natural and engineered channels. GSA Bulletin 2011;; 123 (5-6): 1127–1140. doi: https://doi.org/10.1130/B30244.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract We herein report an example of pyroclastic density current avulsion on 14 June 2006 at Merapi, Indonesia. Four discrete series of multiple dome collapses led to the generation of four individual block-and-ash flows into Kali Gendol valley. All four pyroclastic density currents locally overflowed the channel margins to devastate cultivated terraces along each side of the box-shaped canyon while propagating as much as 2.2 km within adjacent tributaries. The largest destruction was caused by the second and third pyroclastic density currents. Both of these flows partially spilled out of the Gendol valley at a travel distance of 4.9 km, bypassing a sabo dam just upstream of the village of Kaliadem and leaving the village almost completely destroyed and buried by several meters of overbank deposits.The main mechanism of flow avulsion on June 14 was the overflow of up to 20 vol% of the dense, basal part of the pyroclastic density currents onto interfluves. The relative proportions of valley-escaped material increased dramatically in the succession of each of the four pyroclastic density currents. The main geometric parameters controlling flow avulsion and their critical values were quantified through high-resolution real-time kinetic–global positioning system (RTK-GPS) data of the pre-event topography for each of the 14 June flows. This case highlights the way in which a sabo dam can significantly increase the potential of flow avulsion. Key lessons are derived for the future hazard mitigation in valleys subject to volcanic mass flows. Flow-observational and geometric data are combined into a model to derive the kinematic characteristics of the basal, valley-ponding avalanche and the valley-escaping veneer flows, which are otherwise hidden by overriding clouds of elutriated ash. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.