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Steady subsidence of a repeatedly erupting caldera through InSAR observations: Aso, Japan


The relation between unrest and eruption at calderas is still poorly understood. Aso caldera, Japan, shows minor episodic phreatomagmatic eruptions associated with steady subsidence. We analyse the deformation of Aso using SAR images from 1993 to 2011 and compare it with the eruptive activity. Although the dataset suffers from limitations (e.g. atmospheric effects, coherence loss, low signal-to-noise ratio), we observe a steady subsidence signal from 1996 to 1998, which suggests an overall contraction of a magmatic source below the caldera centre, from 4 to 5 km depth. We propose that the observed contraction may have been induced by the release of the magmatic fluids feeding the eruptions. If confirmed by further data, this hypothesis suggests that degassing processes play a crucial role in triggering minor eruptions within open conduit calderas, such as at Aso. Our study underlines the importance of defining any eruptive potential also from deflating magmatic systems with open conduit.

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  • Abe Y, Ohkura T, Shibutani T, Hirahara K, Kato M (2010) Crustal structure beneath Aso caldera, Southwest Japan, as derived from receiver function analysis. J Volcanol Geotherm Res 195(1):1–12. doi:10.1016/j.jvolgeores.2010.05.011

    Article  Google Scholar 

  • Acocella V, Di Lorenzo R, Newhall C, Scandone R (2015) An overview of recent (1988 to 2014) caldera unrest: knowledge and perspectives. Rev Geophys 53. doi:10.1002/2015RG000492

  • Aoki Y, Scholz CH (2003) Interseismic deformation at the Nankai subduction zone and the Median tectonic line, Southwest Japan. J Geophys Res 108(B10):2470. doi:10.1029/2003JB002441

    Article  Google Scholar 

  • Biggs J, Wright TJ, Lu Z, Parsons B (2007) Multi-interferogram method for measuring interseismic deformation: Denali fault, Alaska. Geophys J Int 170:1165–1179. doi:10.1111/j.1365-246X.2007.03415.x

    Article  Google Scholar 

  • Cervelli P, Murray M, Segall P, Aoki Y, Kato T (2001) Estimating source parameters from deformation data, with an application to the March 1997 earthquake swarm off the Izu peninsula, Japan. J Geophys Res 106:11,217–11,238

    Article  Google Scholar 

  • Chiodini G, Todesco M, Caliro S, Del Gaudio C, Macedonio G, Russo M (2003) Magma degassing as a trigger of bradyseismic events: the case of Phlegrean fields (Italy). Geophys Res Lett 30:1434. doi:10.1029/2002GL016790

    Article  Google Scholar 

  • Chiodini G, Caliro S, De Martino P, Avino R, Gherardi F (2012) Early signals of new volcanic unrest at Campi Flegrei caldera? Insights from geochemical data and physical simulations. Geology 40(10):943–946. doi:10.1130/G33251.1

    Article  Google Scholar 

  • Chiodini G, Vandemeulebrouck J, Caliro S, D’Auria L, De Martino P, Mangiacapra A, Petrillo Z (2015) Evidence of thermal-driven processes triggering the 2005–2014 unrest at Campi Flegrei caldera. Earth Planet Sci Lett 414:58–67. doi:10.1016/j.epsl.2015.01.012

    Article  Google Scholar 

  • Chiodini G, Paonita A, Aiuppa A, Costa A, Caliro S, De Martino P, Acocella V, Vandemeulebrouck J (2016) Hotter volcanic unrest for magmas near the critical degassing pressure. Nat Commun. doi:10.1038/ncomms13712

    Google Scholar 

  • de Zeeuw-van Dalfsen E, Rymer H, Sturkell E, Pedersen R, Hooper A, Sigmundsson F, Ófeigsson B (2013) Geodetic data shed light on ongoing caldera subsidence at Askja, Iceland. Bull Volcanol 75(5):709. doi:10.1007/s00445-013-0709-2

  • Dieterich JH, Decker RW (1975) Finite element modeling of surface deformation associated with volcanism. J Geophys Res 80(29):4094–4102

    Article  Google Scholar 

  • Elliott JR, Biggs J, Parsons B, Wright TJ (2008) InSAR slip rate determination on the Altyn Tagh fault, northern Tibet, in the presence of topographically correlated atmospheric delays. Geophys Res Lett 35:L12309. doi:10.1029/2008GL033659

    Article  Google Scholar 

  • Farr TG, Rosen PA, Caro E, Crippen R, Duren R, Hensley S, Kobrick M, Paller M, Rodriguez E, Roth L, Seal D, Shaffer S, Shimada J, Umland J, Werner M, Oskin M, Burbank D, Alsdorf D (2007) The shuttle radar topography mission. Rev Geophys 45(2). doi:10.1029/2005RG000183

  • Ferretti A, Prati C, Rocca F (2001) Permanent scatterers in SAR interferometry. IEEE Trans Geosci Remote 39(1):8–20

    Article  Google Scholar 

  • Geospatial Information Authority of Japan (2011) Crustal deformations around Aso volcano, /kaiho_107_24.pdf (in Japanese)

  • Girona T, Costa F, Newhall C, Taisne B (2014) On depressurization of volcanic magma reservoirs by passive degassing. Journal of Geophysical Research: Solid Earth 119(12):8667–8687. doi:10.1002/2014JB011368

    Google Scholar 

  • Global Volcanism Program (2015) Report on Asosan (Japan). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 40:2. Smithsonian Institution and US Geological Survey

  • Global Volcanism Program (2016) Report on Asosan (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 April-26 April 2016. Smithsonian Institution and US Geological Survey

  • Goldstein RM, Zebker HA, Werner CL (1988) Satellite radar interferometry: two-dimensional phase unwrapping. Radio Sci 23(4):713–720

    Article  Google Scholar 

  • Ikebe S, Watanabe K, Miyabuchi Y (2008) The sequence and style of the 1988–1995 eruptions of Nakadake, Aso volcano, Kyushu. Japan Bull Volcanol Soc Jap 53:15–33

    Google Scholar 

  • Japan Meteorological Agency (2013) National Catalogue of the Active Volcanoes in Japan (fourth edition, English version).

  • Japan Meteorological Agency (2015) Monthly report on earthquakes and volcanoes in Japan, December 2015. Pp. 141

  • Japan Meteorological Agency 2016

  • Jónsson S, Zebker H, Segall P, Amelung F (2002) Fault slip distribution of the 1999 Mw7.1 Hector mine, California, earthquake, estimated from satellite radar and GPS measurements. Bull Seism Soc Am 92:1377–1389

    Article  Google Scholar 

  • Kamata H, Kodama K (1999) Volcanic history and tectonics of the Southwest Japan arc. Island Arc 8:393–403. doi:10.1046/j.1440-1738.1999.00241.x

    Article  Google Scholar 

  • Kawakatsu H, Kaneshima S, Matsubayashi H, Ohminato T, Sudo Y, Tsutsui T, Uhira K, Yamasato H, Ito H, Legrand D (2000) Aso94: Aso seismic observation with broadband instruments. J Volcanol Geotherm Res 101(1):129–154

    Article  Google Scholar 

  • Kruskal JB (1956) On the shortest spanning subtree of a graph and the traveling salesman problem. Proc Am Math Soc 7(1):48–50

    Article  Google Scholar 

  • Lin A, Satsukawa T, Wang M, Asl ZM, Fueta R, Nakajima F (2016) Coseismic rupturing stopped by Aso volcano during the 2016 Mw 7.1 Kumamoto earthquake, Japan. Science 354(6314):869–874. doi:10.1126/science.aah4629

    Article  Google Scholar 

  • Miyabuchi Y, Sugiyama S (2011) 90,000-year phytolith record from tephra section at the northeastern rim of Aso caldera, Japan. Quat Int 246(1):239–246

    Article  Google Scholar 

  • Miyabuchi Y, Ikebe S, Watanabe K (2008) Geological constraints on the 2003-2005 ash emissions from the Nakadake crater lake, Aso volcano Japan. J of Vol and Geoth Res 178(2):169–183. doi:10.1016/j.jvolgeores.2008.06.025 Volcanic lakes and environmental impacts of volcanic fluids.

    Article  Google Scholar 

  • Miyakawa A, Sumita T, Okubo Y, Okuwaki R, Otsubo M, Uesawa S, Yagi Y (2016) Volcanic magma reservoir imaged as a low-density body beneath Aso volcano that terminated the 2016 Kumamoto earthquake rupture. Earth, Planets and Space 68(1):208

    Article  Google Scholar 

  • Miyoshi M, Sumino H, Miyabuchi Y, Shinmura T, Mori Y, Hasenaka T, Nagao, K (2012) K–Ar ages determined for post-caldera volcanic products from Aso volcano, central Kyushu, Japan. J Volcanol Geotherm Res 229:64–73. doi:10.1016/j.jvolgeores.2012.04.003

  • Mogi K (1958) Relations between the eruptions of various volcanoes and the deformation of the ground surfaces around them. Bull Earthq Res Inst U Tokyo 36:99–134

    Google Scholar 

  • Newhall CG, Dzurisin D (1988) Historical unrest at large calderas of the world: USGS Bulletin, v. 1855

  • Ohkura T, Oikawa J (2008) GPS observation of crustal movements at Aso volcano. conference paper Fall Meeting, Volcanol. Soc. Jpn., Morioka, Japan (in Japanese)

  • Okada Y (1985) Surface deformation due to shear and tensile faults in a half-space. Bull Seismol Soc Am 75(4):1135–1154

    Google Scholar 

  • Ono K, Watanabe K, Hoshizumi K, Ikebe S (1995) Ash eruption of the Naka-dake crater, Aso volcano, southwestern Japan. J Volcanol Geotherm Res 66:137–148. doi:10.1016/0377-0273(94)00061-K

    Article  Google Scholar 

  • Ozawa T, Fujita E, Ueda H (2016) Crustal deformation associated with the 2016 Kumamoto earthquake and its effect on the magma system of Aso volcano. Earth, Planets and Space 68(1):186. doi:10.1186/s40623-016-0563-5

    Article  Google Scholar 

  • Pagli C, Sigmundsson F, Árnadóttir T, Einarsson P, Sturkell E (2006) Deflation of the Askja volcanic system: constraints on the deformation source from combined inversion of satellite radar interferograms and GPS measurements. J Volcanol Geotherm Res 152(1–2):97–108 . doi:10.1016/j.jvolgeores.2005.09.014 ISSN 0377–0273

    Article  Google Scholar 

  • Rosen PA, Henley S, Peltzer G, Simons M (2004) Updated repeat orbit interferometry package released. Eos Trans AGU 85(5). doi:10.1029/2004EO050004.

  • Rymer H, Cassidy J, Locke CA, Sigmundsson F (1998) Post-eruptive gravity changes from 1990 to 1996 at Krafla volcano, Iceland. J Volcanol Geotherm Res 87(1):141–149

    Article  Google Scholar 

  • Siebert L, Simkin T, Kimberly P (2010) Volcanoes of the world, 3rd edn. University of California Press, Berkeley 568 p.

    Google Scholar 

  • Sturkell E, Sigmundsson F (2000) Continuous deflation of the Askja caldera, Iceland, during the 1983–1998 non eruptive period. Journal of Geophysical Research: Solid Earth (1978–2012) 105(B11):25671–25684

    Article  Google Scholar 

  • Sturkell E, Einarsson P, Roberts MJ, Geirsson H, Gudmundsson M T, Sigmundsson F, Stefansson R (2008) Seismic and geodetic insights into magma accumulation at Katla subglacial volcano, Iceland: 1999 to 2005. Journal of Geophysical Research: Solid Earth (1978–2012) 113(B3)

  • Sudo Y, Kong L (2001) Three-dimensional seismic velocity structure beneath Aso volcano Kyushu, Japan. Bull Volcanol 63:326–344

    Article  Google Scholar 

  • Sudo Y, Tsutsui T, Nakaboh M, Yoshikawa M, Yoshikawa S, Inoue H (2006) Ground deformation and magma reservoir at Aso volcano: location of deflation source derived from long-term geodetic surveys. Kazan 51(5):291–309 In Japanese

    Google Scholar 

  • Takayama H, Yoshida A (2007) Crustal deformation in Kyushu derived from GEONET data. J Geophys Res 112(B6):B06413

    Article  Google Scholar 

  • Tsutsui T, Sudo Y (2004) Seismic reflectors beneath the central cones of Aso volcano, Kyushu, Japan. J Volcanol Geotherm Res 131(1–2):33–58

    Article  Google Scholar 

  • Unglert K, Savage MK, Fournier N, Ohkura T, Abe Y (2011) Shear wave splitting, vP/vS, and GPS during a time of enhanced activity at Aso caldera. Kyushu J Geophys Res 116:B11203. doi:10.1029/2011JB008520

    Article  Google Scholar 

  • Wang H, Wright TJ, Biggs J (2009) Interseismic slip rate of the northwestern Xianshuihe fault from InSAR data. Geophys Res Lett 36:L03302. doi:10.1029/2008GL036560

    Google Scholar 

  • Wang H, Wright TJ, Yu Y, Lin H, Jiang L, Li C, Qiu G (2012) InSAR reveals coastal subsidence in the Pearl River Delta, China. Geophys J Int 191:1119–1128. doi:10.1111/j.1365-246X.2012.05687.x

    Article  Google Scholar 

  • Wright TJ, Lu Z, Wicks C (2003) Source model for the Mw 6.7, 23 October 2002, Nenana Mountain Earthquake (Alaska) from InSAR. Geophys Res Lett 30(18). DOI:10.1029/2003GL018014.

  • Yang X, Davis PM, Dieterich JH (1988) Deformation from inflation of a dipping finite prolate spheroid in an elastic half-space as a model for volcanic stressing. J Geophys Res 93(B5):4289–4257

    Article  Google Scholar 

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This study was made in the framework of an ESA Category 1 proposal 7486 (V. Acocella responsible). The Supersite initiative (F. Amelung and S. Gross) is gratefully acknowledged for providing Envisat images. PALSAR level 1.0 data from the ALOS satellite are shared among PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface) and provided by the Japan Aerospace Exploration Agency (JAXA) under a cooperative research contract with the Earthquake Research Institute, University of Tokyo. The ownership of PALSAR data belongs to the Ministry of Economy, Trade and Industry, and JAXA. G. Chiodini, E. Sansosti and M. Poland provided useful suggestions on an earlier version of the manuscript. We also would like to thank F. Costa and an anonymous reviewer who provided detailed reviews to improve the manuscript. Finally, thanks to the Associated Editor K.V. Cashman and to the Executive Editor J.D.L. White for additional comments that enhanced this work.

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Correspondence to Adriano Nobile.

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SM1 Mogi sources uncertainties. In the histograms, red dashed bars represent the 90% confidence range, reported in the table. Plain line is the best model. Depth is in km, ΔV is in 10-3 km3/yr, x and y are the distance (in km) between the source and the left/top angle of the area in Fig. 4. (PNG 240 kb)


SM2 Sill source uncertainties. In the histograms, red dashed bars represent the 90% of confidence of the dataset, reported in the table, plain line is the best model. L is the length and W is the width of the sill (km). Op is the opening (cm/yr), Str is the strike (in °), x and y are the distance (in km) between the center of the top side of the sill and the left/top angle of the area in Fig. 4. (PNG 453 kb)


SM3 Ellipsoid source uncertainties. In the histograms, red dashed bars represent the 90% of confidence of the dataset reported in the table, plain red line are the best model. Depth is in km; ΔP is the pressure change in MPa (we considered a crustal rocks shear modulus μ = 35GPa). SAV is vertical semi axis (rotation axis), SAO is the horizontal semi axis (in km), x and y are the distance (in km) between the source center and the left/top angle of the area in Fig. 4. (PNG 336 kb)

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Nobile, A., Acocella, V., Ruch, J. et al. Steady subsidence of a repeatedly erupting caldera through InSAR observations: Aso, Japan. Bull Volcanol 79, 32 (2017).

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