Advertisement

Anatomy and behaviour of a post-eruptive rain lahar triggered by a typhoon on Mayon volcano, Philippines

  • Rodolfo K. S. 
  • Arguden A. T. 
  • Solidum R. U. 
  • Umbal J. V. 
Article

Abstract

Mayon Volcano in the Philippines, one the world's most active, is situated in a moist, tropical-maritime climate with frequent typhoons. A third of Mayon's eruptions generate destructive lahars (volcanic debris flows and hyperconcentrated streamflows). Lahars also occur during quiescent periods when monsoons and typhoons deliver rains of appropriate intensity and duration to the loose debris on the volcano slopes. Both eruption- and post-eruptive lahars occur most frequently during the typhoon-prone October–December season of the Northeast Monsoon. Post-eruptive lahars, the most poorly documented, are exemplified by a debris-flow event triggered by Saling, a typhoon of only moderate intensity, that occurred in Mabinit Channel on the southeast Mayon flank on October 17–18, 1985, one year after the last Mayon eruption.

Detailed pre- and post-Saling surveys docment channel deepening of up to 4 m and maximum lateral erosion of 66 m. The debris flows left prominent, discontinuous multi-level terraces along the length of Mabinit Channel, either from pulsations due to temporary channel blockage, or as levee deposits. A significant volume of debris overtopped channel bends at 250–200 m elevations, coalescing to cover a 200,000 m2 area of 4.5° slope with bouldery lateral deposits 1 m thick on the average. Channelized flows below this level plugged 0.5 km of the original channel and replaced it with a new conduit of comparable size.

The Saling debris-flow deposits have a remarkably uniform sand-silt mode and less prominent, more variable modes in the pebble-boulder range. Shear strengths of the lateral flows ranged from 0.46×104 to 2.32×104 dn cm−2; those of the channelized flows at the plug were significantly higher. Reconstructed flow velocity was 3.8 m sec−1.

Keywords

Shear Strength Debris Flow Tropical Cyclone Pyroclastic Flow Excess Pore Pressure 

morphologie et comportement d'un lahar post-éruptif déclenché par un typhon sur le volcan Mayon, Philippines

Résumé

Le volcan Mayon, localisé aux Philippines est l'un des plus actifs du monde, est situé dans un climat humide, tropical-matritime. Un tiers des éruptions du Mayon produit des lahars destructifs (coulées de débris volcaniques à très forte charge solide). Des Lahars sont générés aussi pendant des périodes tranquilles quand la mousson et les typhons donnent des pluies dont l'intensité et la durée sont suffisantes pour entraîner les débris meubles sur les pentes du volcan. En général, les lahars d'éruption et post-éruptifs du Mayon sont produits entre octobre et décembre, la saison de la mousson du nord-est, quand les typhons sont les plus fréquents. Un exemple de ces lahars post-éruptifs (les moins bien connus), a été provoqué par Saling, un typhon d'intensité moyenne dans le Mabinit Channel sur la pente sud-est du Mayon les 17 et 18 octobre, 1985, un an après la dernière éruption du Mayon.

Las surveillance detaillée du chenal avant et après Saling a montré un approfondissement atteignant 4 m et une érosion maximale de 66 m. Les coulées ont laissé des terrasses étagées discontinues le long du Mabinit Channel, causées soit par des pulsations dues au blocage temporaire du chenal soit par dépôt latéral. Un volume important de débris couvrait une surface de 20 hectares avec une pente de 4.5° avec un dépôt latéral, épais d'environ 1 m. Les coulées en-dessous de ce niveau, colmataient le chenla d'origine sur 0,5 km et remplaçaient ce dernier par un nouveau chenal de taille comparable.

Les dépôt des lahars dus au typhon Saling présentent un mode dans les sables-limons remarquablement uniforme, et au contraire plus varié au niveau des cailloux. La résistance au cisaillement du dépôt latéral est de 0,46×104 à 2,32×104 dn cm−2, est nettement plus élevée pour le matériau qui remplit le chenal. La vitesse des coulées a été estimée à 3,8 m sec−1.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. ARGUDEN A.T., RODOLFO K.S., (1986): Sedimentology of hot and cold lahar deposits produced by the 1984 eruption of Mayon Volcano, Philippines. Phil. Jour. Volc. 3: 37–46.Google Scholar
  2. ARGUDEN A.T., UMBAL J.V., RODOLFO K.S., (1989): 17 October 1987 typhoon-triggered lahar on Mayon Volcano, Philippines. Proc. Int. Conf. on Volcanoes, Kagoshima, Japan p. 654–657.Google Scholar
  3. BAGNOLD R.A., (1954): Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear. proc. R. Soc. London. Ser. A 225: 49–63.CrossRefGoogle Scholar
  4. BEVERAGE J.P., CULBERTSON J.K. (1964): Hyperconcentrations of suspended sediment. Jour. Hydrol. Div., American Society of Civil Engineers. 90: 117–126.Google Scholar
  5. CARTER R.M., (1975): A discussion and classification of subaqueous mass-transport with particular application to grainflow, slurry-flow, and fluxoturbidites. Earth Sci. Reviews. 11: 145–177.CrossRefGoogle Scholar
  6. CHOW V.T., (1959): Open channel hydraulics. McGraw Hill. 680 p.Google Scholar
  7. COOLEY M.E., ALDRIDGE B.N., EULER, R.C. (1977): Effects of the catastrophic flood of December 1966, north rim area, eastern Grand Canyon. Arizona. U.S. Geol. Surv. Prof. Pap. 980: 43.Google Scholar
  8. CORPUZ E.G., (1985): Chronology of the September–October 1984 eruption of Mayon Volcano, Philippines. Phil. Jour. Volc. 2: 36–51.Google Scholar
  9. COSTA J.E., (1984): Physical geomorphology of debris flows, in: Developments and Applications of Geomorphology, Eds: J.E. Costa, J.P. Fleischer, Springer-Verlag, pp. 268–317.Google Scholar
  10. CRUZ J.B., SOLIDUM R.U., CORPUZ E.G. (1985): Transport, emplacement and textural characteristics of the Bonga pyroclastic flows of the 1984 eruption of Mayon Volcano. Phil. Jour. Volcan. 2: 68–93.Google Scholar
  11. CURRY R.R., (1966): Observation of alpine mudflows in the Tenmile Range, Central Colorado. Geol. Soc. Am. Bull. 77: 771–776.CrossRefGoogle Scholar
  12. ENOS, P., (1977): Flow regimes in debris flows. Sedimentology. 24: 133–142.CrossRefGoogle Scholar
  13. FERNANDEZ J.C. (1971): Mayon mudflows. Comvol. Let. 8: 3–5.Google Scholar
  14. FISHER R.V., SCHMINCKE H.U., (1984): Pyroclastic Rocks: Springer-Verlag. 472 p.Google Scholar
  15. HAMPTON M.A., (1972): The role of subaqueous debris flow in gene-rating turbidity currents. J. Sediment. Petrol. 42: 775–793.Google Scholar
  16. HAMPTON M.A., (1975): Competence of fine-grained debris flows. J. Sediment. Petrol. 45: 834–844.Google Scholar
  17. HAMPTON M.A., (1979): Buoyancy in debris flows. J. Sediment. Petrol. 49: 753–758.Google Scholar
  18. JANDA R.J., SCOTT K.M., NOLAN K.M., MARTINSON H.A., (1981): Lahar movement, effects, and deposits, in: The 1980 eruptions of Mount St. Helens, Washington. Eds: P.W. Lipman and D.R. Mullineaux, U.S. Geol. Surv. Prof. Pap. 1250: 461–478.Google Scholar
  19. JOHNSON A.M., (1970): Physical Processes in Geology. Freeman, Cooper. 577 p.Google Scholar
  20. JOHNSON A.M., RODINE J.R., (1984): Debris flows, in: Slope Instability, Eds: D. Brunsden, D.B. Prior, Wiely. pp. 267–361.Google Scholar
  21. LOWE D.R., WILLIAMS S.N., LEIGH J., CONNOR C.B., GEMMELL J.B., STOIBER R.E., (1986): Lahars initiated by the 13 November, 1985 eruption of Nevado-Del-Ruiz, Columbia. Nature, 324: 51–53.CrossRefGoogle Scholar
  22. MAGALIT C.T., RUELO H.B. (1985): Features and characteristics of the 1984 Mayon lava flows. Phil. Jour. Volcanol. 2: 1/2: 52–67.Google Scholar
  23. MIDDLETON G.V., HAMPTON M.A., (1976): Subaqueous sediment transport and depositions by sediment gravity flows, in: Stanley D.J. Swift J.P. (eds). Marine sediment transport and environmental management. Wiley. New York. pp. 197–218, 1241-I: 1–35.Google Scholar
  24. MOORE T.G., MELSON W.G., (1969): Nuees ardentes of the 1968 eruption of Mayon Volcano, Philippines. Bull. Volcan. 2: 33: 600–620.CrossRefGoogle Scholar
  25. NARANJO J.L., SIGURDSSON J., CAREY S.N., FRITZ W., (1986): Eruption of the Nevado del Ruiz Volcano, Columbia on 13 November, 1985: Tephra falls and Jahars. Sciences. 233: 961–967.CrossRefGoogle Scholar
  26. NEWHALL C.G., (1977): Geology and petrology of Mayon Volcano (M.S. thesis. Davis, California, Univ. Calif. 292 p.Google Scholar
  27. NEWHALL C.G. (1979): Temporal evolution of the lavas of Mayon Volcano, southeastern Luzon, Philippines. Jour. Volc. Geotherm. Res. 6: 61–83.CrossRefGoogle Scholar
  28. NARANJO J.L., SIGURDSSON J., CAREY S.N., FRITZ W., (1986): Eruption of the Nevado del Ruiz Volcano, Columbia on 13 November, 1986. Tephra falls and lahars. Science. 233: 961–967.CrossRefGoogle Scholar
  29. PIERSON T.C., (1981): Dominant particle support mechanisms in debris flows at Mount Thomas, New Zealand, and implications for flow mobility. Sedimentology 28: 49–60.CrossRefGoogle Scholar
  30. PIERSON T.C., (1985): Initiation and flow behaviour of the 1980 Pine Creck and Muddy River lahars, Mount St. Helens, Washington. Geol. Soc. Am. Bull. 96: 1056–1069.CrossRefGoogle Scholar
  31. PIERSON T.C., (1986): Flow behaviour of channelized debris flows, Mount St. Helens, Washington, in: Hillslope Processes, Ed: A.D. Abrahams. Boston, Allen & Unwin, pp. 269–296.Google Scholar
  32. PIERSON T.C., COSTA J.E., (1987): A rheologic classification of subaerial sediment-water flows. Geol. Soc. Am. Review in Engineering Geology. III: 1–11.Google Scholar
  33. PUNONGBAYAN, R.S., (1985): An approach for estimating ages of active volcanoes. Phil. Jour. Volcan. 2: 191–205.Google Scholar
  34. PUNONGBAYAN R.S., (198): Profile morphology and internal structure of Mayon Volcano. Phil. Jour. Volcan. 2: 1560–171.Google Scholar
  35. RAMOS-VILLARTA S.C., CORPUZ E.G., NEWHALL C.G., (1985): Eruptive history of Mayon Volcano, Philippines. Phil. Jour. Volcan. 2: 1–34.Google Scholar
  36. RODINE J.D., JOHNSON A.M., (1976): The ability of debris heavily freighted with coarse clastic materials to flow on gentle slopes. Sedimentology. 23: 213–234.CrossRefGoogle Scholar
  37. RODOLFO K.S., (1989): Origin and early evolution of a lahar channel at Mabinit, Mayon Volcano, Philippines. Geol. Soc. America Bull. 100: 351–370.Google Scholar
  38. SCRIVENOR J.B., (1929): The mudstreams (‘Lahars’) of Gunong Keleot in Java. Geol. Mag. 66: 433–434.CrossRefGoogle Scholar
  39. SIMKIN T., McCLELLAND L., BRIDGE D., NEWHALL, C., LATTER J.H., (1981): Volcanoes of the World: A Regional Directory, Gazeteer, and Chronology of Volcanism During the Last 10,000 Years. Hutchinson Ross Publishing Co., Stroudsburg Pa., 233 p.Google Scholar
  40. SMITH G.A., (1986): Coarse-grained nonmarine volcaniclastic sediment: Terminology and depositional processes. Geol. Soc. Amer. Bull. 97: 1–10.CrossRefGoogle Scholar
  41. TER-STEPANIAN G., (1968): On the avalanche-type mechanisms of cohesive hydro-dynamic mudflows. Prob. Geomech. 2 38–45.Google Scholar
  42. UMBAL J.V., (1986): Recent lahars of Mayon Volcano. Phil. Jour. Volcanol. 3: 27–36.Google Scholar
  43. UMBAL J.V., ARGUDEN A.T., RODOLFO K.S. (in press): Comparison of eruption and typhoon-triggered lahar velocities from indirect measurements, Mayo Volcano, Philippines. Phil. Jour. Volcan.Google Scholar
  44. WALDRON H.H., (1967): Debris flow and erosion control problems caused by the ash eruptions of Irazu Volcano, Costa Rica. U.S. Geol. Surv. Bull. 1241-I: 1–35.Google Scholar

Copyright information

© International Association of Engineering Geology 1989

Authors and Affiliations

  • Rodolfo K. S. 
    • 1
  • Arguden A. T. 
    • 1
  • Solidum R. U. 
    • 2
  • Umbal J. V. 
    • 2
  1. 1.Department of Geological SciencesUniversity of Illinois at ChicagoChicagoU.S.A.
  2. 2.Philippines Institute of Volcanology and SeismologyQuezon CityPhilippines

Personalised recommendations