Skip to main content

Gravity basement of the Guinsaugon landslide along the Philippine Fault Zone

Abstract

A gravity survey was conducted in Guinsaugon, St. Bernard, Southern Leyte, Philippines, to determine the subsurface structure of the Leyte segment of the Philippine Fault Zone (PFZ), where a massive landslide killed 1119 villagers on 17 February 2006. The landslide started on top of a 780-m-high ridge linked with the PFZ. The build-up of pore pressure in the slope due to saturation and possible earthquake-triggered ground shaking along the PFZ, may have initiated the landslide. A two-dimensional structure using homogeneous density models was applied to interpret the gravity anomalies in the Guinsaugon landslide. The most suitable model depicts a deep, narrow graben filled with low-density sediments. The graben is 1.5 km wide and 2 km deep and has a density contrast of -0.4 g/cm3. The western boundary of the graben is steep and coincides with the terminus (southern) Leyte segment of the PFZ. The existence of a deep-seated seismically active fault at the foot of the steep slopes and the soft sediments in the narrow graben are important factors in understanding the trigger and failure mechanisms of the landslide and in the assessment of hazards and risks due to landslides and earthquakes.

References

  • Bautista, M. L. P. and K. Oike, Estimation of the magnitudes and epicenters of Philippine historical earthquakes, Tectonophysics, 317, 137–169, 2000.

    Article  Google Scholar 

  • Besana, G. M. and M. Ando, The central Philippine Fault Zone: location of great earthquakes, slow events, and creep activity, Earth Planets Space, 57, 987–994, 2005.

    Article  Google Scholar 

  • Besana, G. M., J. A. Daligdig, N. M. Tungol, M. I. T. Abigania, B. Santos, B. J. T. Punongbayan, H. Penarubia, R. R. Maximo, L. Torrevillas, R. Dela Cruz, K. I. Papiona, and R. Lumbang, The Final Report of the 2003 Masbate Quake, PHIVOLCS Open File Report, pp. 1–30, 2003.

    Google Scholar 

  • Catane, S. G., H. B. Cabria, C. P. Jr. Tomarong, R. M. Jr. Saturay, M. A. H. Zarco, and W. C. Pioquinto, Catastrophic rockslide-debris avalanche at St. Bernard, Southern Leyte, Philippines, Landslides, SpringerLink, doi:10.1007/s10346-006-0050-3, 2006.

    Google Scholar 

  • Cole, J., R. McCabe, T. Moriarty, J. A. Malicse, F. G. Delfin, H. Tebar, and H. P. Ferrer, A preliminary Neogene paleomagnetic data set from Leyte and its relation to motion on the Philippine Fault, Tectonophysics, 168, 205–221, 1989.

    Article  Google Scholar 

  • Daag, A. S., O. Molina, D. Buena, and E. Gumabon, Deterministic modeling of rain- and earthquake-induced landslides in mountainous environments transected by an active fault, presented at Caravan Seminar on Geospatial Technologies for Disaster Mitigation: Philippines Perspective, Philippine Institute of Volcanology and Seismology, Makati City, Philippines, 27 November 2006, 2006.

    Google Scholar 

  • Domasig, W. F., Report on the ground investigation of reported landslides and ground fissures and other earthquake-related damages in Cabalian—St. Bernard area in Southern Leyte, memorandum report, 6 p., Mines & Geosciences Development Service, 1991.

    Google Scholar 

  • Duquesnoy, T. H., Contribution de la geodesie a l’etude de grands decrochements actifs associes a des zones de subduction a convergence oblique, These de doceur en science, University of Paris-XI, Orsay, 1997.

    Google Scholar 

  • Duquesnoy, T. H., E. Barrier, M. Kasser, M. Aurelio, R. Gaulon, R. S. Punongbayan, C. Rangin and the French-Philippine Cooperation Team, Detection of creep along the Philippine Fault: first results of geodetic measurements on Leyte island, central Philippines, Geophys. Res. Lett., 21(11), 975–978, 1994.

    Article  Google Scholar 

  • Endo, H., S. Watanabe, M. Makino, Y. Murata, K. Watanabe, and A. Urabe, Damage caused by the 1995 Hyogoken-Nanbu Earthquake and concealed faults in the Hanshin area, Hyogo Pref. Japan, Quat. Res., 35, 165–178, 1996.

    Article  Google Scholar 

  • Ferguson, J. F., R. N. Felch, C. L. V. Aiken, J. S. Oldow, and H. Dockery, Models of the Bouguer gravity and geologic structure at Yucca Flat, Nevada, Geophysics, 53, 231–244, 1988.

    Article  Google Scholar 

  • GSJ Gravity Survey Group, On the standard procedure SPECG1988 for evaluating the correction of gravity at the Geological Survey of Japan, Bull. Geol. Surv. Jpn., 40, 601–611, 1989 (in Japanese with English abstract).

    Google Scholar 

  • JICA-MMAJ, The mineral exploration—mineral deposits and tectonics of two contrasting geologic environments in the Republic of the Philippines, Consolidated report on Leyte, Dinagat and Surigao areas, Japan International Cooperation Agency-Metal Ming Agency of Japan, Japan, 1990.

    Google Scholar 

  • Komazawa, M., Gravimetric analysis of Aso Volcano and its interpretation, J. Geodetic Soc. Jpn., 41, 17–45, 1995.

    Google Scholar 

  • Lanuza, A. G., A. V. Chu, E. A. Mangao, D. S. Soneja, R. Sanez, and D. C. Garcia, Aftershocks observation of 05 July 1994 earthquake in Cabalian area, Southern Leyte, PHIVOLCS internal report, 35 p., Philippine Institute of Volcanology and Seismology, 1994.

    Google Scholar 

  • Litinsky, V. A., Concept of effective density: key to gravity depth determinations for sedimentary basin, Geophysics, 54, 1474–1482, 1989.

    Article  Google Scholar 

  • Lukandu, A. I., S. Okuyama, and S. Takemoto, Gravity inversion modeling across fault/tectonic lines in the Central Ranges in Honshu, Japan, J. Geol. Soc. Jpn., 49, 73–82, 2003.

    Google Scholar 

  • Makino, M., An improved method for two-dimensional gravity analysis by using logarithmic functions: an application to the Kobe area, Butsuri-Tansa, 50, 123–131, 1997 (in Japanese with English abstract).

    Google Scholar 

  • Makino, M. and H. Endo, Gravity survey around the area of the Harihara-gawa debris flow at Izumi, Kagoshima Prefecture, Butsuri-Tansa, 52, 153–160, 1999 (in Japanese with English abstract).

    Google Scholar 

  • Murata, Y., Y. Suda, and T. Kikuchi, Rock physical properties of Japan—density, magnetism, P-wave velocity, porosity, thermal conductivity, Open File Report 276, 302 p., Geological Survey of Japan, 1991 (in Japanese).

    Google Scholar 

  • PAGASA, Rainfall data from Otikon, Libagon, Southern Leyte, Philippine Atmospheric Geophysical and Astronomical Services Agency (PA-GASA), Philippines, 2006.

    Google Scholar 

  • Suda, Y., Y. Murata, T. Kikuchi, and N. Hanaoka, Physical properties database of rocks (PROCK), Open File Report 155, 231 p., Geological Survey of Japan, 1991 (in Japanese).

    Google Scholar 

  • Suwa, H., Catastrophe by the 17 February 2006 Southern Leyte landslide in Phillipine, J. Jpn. Soc. Natural Disaster Sci., 25, 83–97, 2006 (in Japanese with English abstract).

    Google Scholar 

  • Talwani, M., J. L. Worzel, and M. Landisman, Rapid gravity computations for two-dimensional bodies with application to the Mendocino submarine fracture zone, J. Geophys. Res., 64, 49–59, 1959.

    Article  Google Scholar 

  • Williams, H. A., J. Cassidy, C. A. Locke, and K. B. Sporli, Delineation of a large ultramafic massif embedded within a major SW Pacific suture using gravity methods, Tectonophysics, 424, 119–133, 2006.

    Article  Google Scholar 

  • Yokoyama, I. and S. Ohkawa, The subsurface structure of the Aira Caldera and its vicinity in the southern Kyushu, Japan, J. Volcanol. Geotherm. Res., 30, 253–282, 1986.

    Article  Google Scholar 

  • Zarco, M. A. H., S. G. Catane, H. B. Cabria, R. M. Saturay, Jr., and A. S. Mirasol-Robert, Failure mechanism of a massive landslide: analysis of the 17 February 2006 Guinsaugon rockslide-debris avalanche, Philippines, Proceedings of the 4th Civil Engineering Conference in the Asian Region, Taipei, Taiwan, June 26-28, 2007.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Masahiko Makino.

Rights and permissions

Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.

Reprints and permissions

About this article

Cite this article

Makino, M., Mandanas, A.A. & Catane, S.G. Gravity basement of the Guinsaugon landslide along the Philippine Fault Zone. Earth Planet Sp 59, 1067–1071 (2007). https://doi.org/10.1186/BF03352049

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03352049

Key words