Glowing avalanches from the 1974 eruption of the volcano Fuego, Guatemala

Abstract

Research Article| March 01, 1978 Glowing avalanches from the 1974 eruption of the volcano Fuego, Guatemala DAVID K. DAVIES; DAVID K. DAVIES 1Department of Geology, University of Missouri at Columbia, Columbia, Missouri 652013Present address: (Davies) Department of Geosciences, Texas Tech University, Lubbock, Texas 79409. (Quearry) Texaco, Inc., P.O. Box 60252, New Orleans, Louisiana 70160 Search for other works by this author on: GSW Google Scholar MICHAEL W. QUEARRY; MICHAEL W. QUEARRY 1Department of Geology, University of Missouri at Columbia, Columbia, Missouri 652013Present address: (Davies) Department of Geosciences, Texas Tech University, Lubbock, Texas 79409. (Quearry) Texaco, Inc., P.O. Box 60252, New Orleans, Louisiana 70160 Search for other works by this author on: GSW Google Scholar SAMUEL B. BONIS SAMUEL B. BONIS 2División Geológica, Instituto Geográfico Nacional, Avenida las Americas, Guatemala City, Guatemala Search for other works by this author on: GSW Google Scholar GSA Bulletin (1978) 89 (3): 369–384. https://doi.org/10.1130/0016-7606(1978)89<369:GAFTEO>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation DAVID K. DAVIES, MICHAEL W. QUEARRY, SAMUEL B. BONIS; Glowing avalanches from the 1974 eruption of the volcano Fuego, Guatemala. GSA Bulletin 1978;; 89 (3): 369–384. doi: https://doi.org/10.1130/0016-7606(1978)89<369:GAFTEO>2.0.CO;2 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 Glowing avalanches from the 1974 eruption of the volcano Fuego, Guatemala, deposited between 0.005 and 0.01 km3 of nonimbricated, nongraded, nonwelded debris on the southern flanks of the volcano. Avalanches emerged from notches in the crater rim, and traveled some 7 km from the vent at an average speed of 60 km/hr. Each glowing avalanche consisted of two parts, (1) the main mass of moving debris, or underflow, and (2) a superjacent gas and dust cloud. The postdepositional thickness of individual underflows is generally less than 2 m, but successions of glowing avalanches produced deposits as much as 15 m thick in some ravines. The underflows and their superjacent gas and dust clouds followed topographic lows. Where underflows were confined laterally by valley walls, the surface of the underflow was featureless, after deposition. Where underflows were able to spread laterally, they developed a surface morphology of channels, levees, and overbank areas. The coarsest fragments were deposited in the channels.The underflows probably flowed in laminar fashion as high concentration dispersions, similar to normal debris flows. No unequivocal evidence of large-scale gas expansion of the underflows was noted. Gas emission is considered to have occurred during transportation, but it probably played a minor role in fluidization of the underflow. The ability of these glowing avalanches to transport particles as much as 5 m in diameter some 7 km from the crater is considered to be a reflection of the high yield strength of the underflow.Deposits from the 1974 eruption had a mean grain size of −3.00ϕ (8 mm), were extremely poorly sorted (σ1 = 4.6) strongly fine skewed (SKI = 0.63), and platykurtic (KG = 0.71). All grain size distributions were bimodal with a dominant intermodal low at −1.0ϕ (2 mm). The small percentage of particles in the −1.0ϕ size interval is considered to reflect the inherent mechanical instability of particles of this size.Turbulently flowing gas and dust clouds, as much as 1,000 m high, accompanied each avalanche, and cloud height increased with increasing distance of travel. The fine-grained dust of the superjacent gas and dust clouds was not deposited on top of the underflow. Prevailing winds blew the fine-grained component to the west-southwest. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.