Volcanic Subsidence Triggered by Megathrust Earthquakes
Youichiro Takada* and Yo Fukushima**
*Disaster Prevention Research Institute, Kyoto University, Kamitakara Observatory, 2296-2 Hongo, Kamitakara-machi, Takayama city, Gifu 506-1317, Japan
**Disaster Prevention Research Institute, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
Studies using spaceborne interferometric synthetic aperture radar (InSAR) analysis showed that two megathrust earthquakes – the 2011Mw9.0 Tohoku-oki earthquake in Japan and the 2010Mw8.8Maule earthquake in Chile – triggered unprecedented subsidence in multiple volcanoes. There are strong similarities in the characteristics of the surface deformation in Japan and Chile: (1) Maximum subsidence is about 15 cm. (2) Areas of subsidence are elliptically elongated in a north-south direction perpendicular to the principal axis of the extensional stress change. (3) Most of this subsidence is coseismic. These similarities imply that volcanic subsidence triggered by the megathrust earthquakes is a ubiquitous phenomenon. Nonetheless, the mechanism of subsidence is yet to be investigated. Two main hypotheses have been proposed thus far: 1) The localized deformation of hot and weak plutonic bodies. 2) Water release from large hydrothermal reservoirs beneath the volcanoes.
-  S. Ozawa, T. Nishimura, H. Suito, T. Kobayashi, M. Tobita, and T. Imakiire, “Coseismic and postseismic slip of the 2011 magnitude-9 Tohoku-Oki earthquake,” Nature, Vol.475, pp. 373-377, 2011.
-  M. Sato et al., “Displacement above the hypocenter of the 2011 Tohoku-Oki earthquake,” Science, Vol.332, pp. 1395, June 2011.
-  D. Massonnet, M. Rossi, C. Carmona, F. Adragna, G. Peltzer, K. Feigl, and T. Rabaute, “The displacement field of the Landers earthquake mapped by radar interferometry,” Nature, Vol.364, pp. 138-142, July 1993.
-  D. Massonnet, P. Briole, and A. Arnaud, “Deflasion of Mount Etna monitored by spaceborne radar interferometry,” Nature, Vol.375, pp. 567-570, June 1995.
-  Y. Takada and Y. Fukushima, “Volcanic subsidence triggered by the 2011 Tohoku earthquake in Japan,” Nature Geoscience, Vol.6, pp. 637-641, August 2013.
-  T. Ozawa and E. Fujita, “Local deformations around volcanoes associated with the 2011 off the Pacific coast of Tohoku earthquake,” J. Geophys. Res. Vol.118, pp. 390-405, doi:10.1029/2011JB009129, 2013.
-  M. E. Pritchard, J. A. Jay, F. Aron, S. T. Henderson, and L. Lara, “Subsidence at southern Andes volcanoes induced by the 2010 Maule, Chile earthquake,” Nature Geoscience, Vol.6, pp. 632-636, August 2013.
-  S. Jónsson, “Volcanology: Sunken volcanoes,” Nature Geoscience, Vol.6, pp. 591-592, August 2013.
-  Y. Yagi and Y. Fukahata, “Rupture process of the 2011 Tohokuoki earthquake and absolute elastic strain release,” Geophys. Res. Lett, Vol.38, L19307, doi:10.1029/2011GL048701, 2011.
-  T. Nishimura, H. Munekane, and H. Yarai, “The 2011 off the Pacific coast of Tohoku Earthquake and its aftershocks observed by GEONET,” Earth Planets Space, Vol.63, pp. 631-636, 2011.
-  S. Miyazaki, J. J. McGuire, and P. Segall, “Seismic and aseismic fault slip before and during the 2011 off the Pacific coast of Tohoku Earthquake,” Earth Planes Space, Vol.63, pp. 637-642, 2011.
-  S. Lorito et al., “Limited overlap between the seismic gap and coseismic slip of the great 2010 Chile earthquake,” Nature Geoscience, Vol.4, pp. 173-177, 2011.
-  H. Takahashi, “Static strain and stress changes in eastern Japan due to the 2011 off the Pacific coast of Tohoku Earthquake, as derived from GPS data,” Earth Planets Space, Vol.63, pp. 741-744, 2011.
-  A. Tanaka, M. Yamano, Y. Yano, and M. Sasada, “Geothermal gradient and heat flow data in and around Japan (I): Appraisal of heat flow from geothermal gradient data,” Earth Planets and Space, Vol.56, pp. 1191-1194, 2004.
-  Geological Survey of Japan, Distribution map and catalogue of hot and mineral springs in Japan [CD-ROM], 2nd Ed., Digital Geosci. Map GT-2, Natl. Inst. of Adv. Ind. Sci. and Technol., Tsukuba, Japan, 2005 (in Japanese with English abstract).
-  T. Yoshida, “The evolution of arc magmatism in the NE Honshu arc, Japan,” Sci. Rep. Tohoku Univ., Vol.36, pp. 131-149, 2001.
-  T. Yoshida et al., “Evolution of Late Cenozoic magmatism in the NE Honshu arc and its relation to the crust-mantle structures,” The Quaternary Research, Vol.44, pp. 195-216, 2005 (in Japanese with English abstract and figure legend).
-  N. Doi et al., “Genesis of the plutonic-hydrothermal system around Quaternary granite in the Kakkonda geothermal system, Japan,” Geothermics, Vol.27, pp. 663-690, doi:10.1029/2004JB003268, 1998.
-  V. Cayol and F. H. Cornet, “3D mixed boundary elements for elastostatic deformation field analysis,” Int. J. Rock Mech. Min. Sci., Vol.34, pp. 275-287, 1997.
-  Y. Yukutake et al., “Remotely-triggered seismicity in the Hakone volcano following the 2011 off the Pacific coast of Tohoku Earthquake,” Earth Planets Space, Vol.63, pp. 737-740, 2011.
-  S. Ohmi, H.Wada, and Y. Hamada, “Seismic activity near the Yakedake volcano in the Hida mountain range after the 2011 off the Pacific coast of Tohoku earthquake,” J. Seismol. Soc. Jpn., Vol.65, pp. 85-94, 2012 (in Japanese with English abstract).
-  A. Hashima, Y. Takada, Y. Fukahata, and M. Matsu’ura, “General expressions for internal deformation due to a moment tensor in an elastic/viscoelastic multilayered half-space,” Geophys. J. Int., Vol.175, pp. 992-1012, 2008.
-  Coordinating Committee for Prediction of Volcanic Eruption, Report issued at the 120th meeting of the committee, 7 June 2011 (in Japanese),
http://www.seisvol.kishou.go.jp/tokyo/STOCK/kaisetsu/CCPVE/shiryo/120/120_no05.pdf [accessed December 26, 2013]
-  P. L. Whelly, J. Jay, E. S. Calder, M. E. Pritchard, N. J. Cassidy, S. Alcaraz, and A. Pavez, “Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano.Chile,” Bull. Volcanol., Vol.74, pp. 511-531, 2012.
-  E. Yamada, “Geologic development of the Onikobe caldera, Northeast Japan, with special reference to its hydrothermal system,” Rept. Geol. Surv. Japan, Vol.268, pp. 61-190, 1988.
-  S. Jónsson, P. Segall, R. Pedersen, and G. Björnsson, “Postearthquake ground movements correlated to pore-pressure transients,” Nature, Vol.424, July 2003.
-  M. Manga and C. Y. Wang, “Earthquake hydrology,” in Treatise on Geophysics, Vol.4, H. Kanamori (Eds.), Amsterdam, Elsevier, 2007. pp. 293-320.
-  C. H. Mohr, D. R. Montgomery, A. Huber, A. Bronstert, and A. Iroumé, “Streamflow response in small upland catchments in the Chilean coastal range to the Mw8.8 Maule earthquake on 27 February 2010,” J. Geophys. Res., Vol.117, F02032, doi:10.1029/2011JF002138, 2012.
-  P. Wessel and W. H. F. Smith, “New, improved version of Generic Mapping Tools released,” EOS Trans. Amer. Geophys. U., Vol.79, pp. 579, 1998.