Nuées Ardentes of the 1968 Eruption of Mayon Volcano, Philippines
- 230 Downloads
Mayon Volcano, southeastern Luzon, began a series of explosive eruptions at 0900 April 21, 1968, and by May 15 more than 100 explosions had occurred, at least 6 people had been killed, and roughly 100 square km had been covered by more than 5 cm of airfall ash, blocky ash flows, and a lava flow. All material crupted was porphyritic augite-hypersthene andesite.
Explosions from the summit crater (elevation 2460 m) ejected large quantities of ash and incandescent blocks to a height exceeding 600 m and produced ash-laden clouds which rose to heights of 3 to 10 km. Backfall of the coarser material fed nuées ardentes which repeatedly swept down ravines on all sides of the volcanic cone. The velocity of one nuée ardente ranged from 9 to 63 m per sec. The largest nuées descended to the southwest and reached as far as 7 km from the summit. An aa lava flow also descended 3 1/2 km down this flank.
The nuées ardentes deposited pyroclastic flows that contained large breadcrust-surfaced blocks averaging about 30 cm across, but occasionally reaching 25 m in greatest dimension. These blocks were still very hot in their interiors several days later. Surrounding the pyroclastic flows is a seared zone as much as 2 km wide, but averaging a few hundred meters, in which vegetation is charred and splintered, but over which only a thin layer of airfall ash was deposited.
KeywordsLava Flow Pyroclastic Flow Explosive Eruption Summit Crater Coconut Palm
Unable to display preview. Download preview PDF.
- Aramaki, S., 1956,The 1783 activity of Asama Volcano. Part I: Japanese Jour. Geol. and Geography, v. 27, n. 2–4, p. 189–229.Part II, 1957 — v. 28, n. 1–3, p. 11–33.Google Scholar
- Escher, B. G., 1933,On a classification of central eruptions according to gas pressure of the magma and viscosity of the lavas: Leid. Geol. Meded., Deel 6, Aft. I, p. 45–49.Google Scholar
- Faustino, L. A., 1929,Mayon Volcano and its eruptions: Philipp. Jour. Sci., v. 40, p. 1–47.Google Scholar
- LaCroix, A., 1904,La Montagne Pelëe et ses eruptions. Paris: Masson et Cie, 662 p.Google Scholar
- Mellor, Malcom, 1968,Avalanches [pt.]of Cold regions science and engineering: U. S. Army Cold Regions Research and Eng. Lab. (USA CRREL) monographs, pt. 3, sec. A3, 215 p.Google Scholar
- Smith, R. L., 1960,Ash flows: Geol. Soc. America Bull., v. 71, p. 795–842.Google Scholar
- Van Padang, M. Neumann, 1953,Catalogue of the active volcanoes of the world; Part II, Philippine Islands and Cochin China: International Assn. of Volcanology, 49 p.Google Scholar