Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis

eruption, magma storage had increased by 3.7– 5.2 ×1 0 7 m 3 or 85–100% of the 1997 eruption volume. We propose that the supply rate decreased in response to the diminishing pressure gradient between the shallow storage zone and a deeper magma source region. Eventuallytheeffectsofcontinuingmagmasupplyandvesiculationofstoredmagmacaused acriticalpressurethresholdtobeexceeded,triggeringthe2008eruption.Asimilarpatternof initially rapid inflation followed by oscillatory but generally slowing inflation was observed prior to the 1997 eruption. In both cases, withdrawal of magma during the eruptions depressurized the shallow storage zone, causing significant volcano‐wide subsidence and initiating a new intereruption deformation cycle.

[1]  Herbert F. Wang.  Theory of Linear Poroelasticity with Applications to Geomechanics and Hydrogeology , 2000 .

[2]  Zhong Lu,et al.  Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis: 2. Coeruptive deflation, July–August 2008 , 2010 .

[3]  S. McNutt,et al.  Global volcanic earthquake swarm database and preliminary analysis of volcanic earthquake swarm duration , 1996 .

[4]  Analysis and interpretation of volcano deformation in Alaska: Studies from Okmok and Mt. Veniaminof volcanoes , 2008 .

[5]  R. Sparks,et al.  Forecasting volcanic eruptions , 2003 .

[6]  A. Iserles.  Numerical recipes in C—the art of scientific computing , by W. H. Press, B. P. Flannery, S. A. Teukolsky and W. T. Vetterling. Pp 735. £27·50. 1988. ISBN 0-521-35465-X (Cambridge University Press) , 1989, The Mathematical Gazette.

[7]  Gianfranco Fornaro,et al.  A new algorithm for surface deformation monitoring based on small baseline differential SAR interferograms , 2002, IEEE Trans. Geosci. Remote. Sens..

[8]  Zhong Lu,et al.  Deformation associated with the 1997 eruption of Okmok volcano, Alaska , 2002 .

[9]  Charles A. Williams,et al.  The effects of topography on magma chamber deformation models: Application to Mt. Etna and radar interferometry , 1998 .

[10]  William H. Press,et al.  Numerical recipes in C , 2002 .

[11]  D. Mctigue,et al.  Volume of magma accumulation or withdrawal estimated from surface uplift or subsidence, with application to the 1960 collapse of Kilauea volcano , 1994 .

[12]  Jeffrey T. Freymueller,et al.  Tracking magma volume recovery at Okmok volcano using GPS and an unscented Kalman filter , 2009 .

[13]  James H. Dieterich,et al.  Finite element modeling of surface deformation associated with volcanism , 1975 .

[14]  P. Segall,et al.  Magma compressibility and the missing source for some dike intrusions , 2008 .

[15]  K. Dean,et al.  The 1997 eruption of Okmok Volcano, Alaska: a synthesis of remotely sensed imagery , 2003 .

[16]  James H. Dieterich,et al.  Deformation from Inflation of a Dipping Finite Prolate Spheroid in an Elastic Half‐Space as a Model for Volcanic Stressing , 1988 .

[17]  K. Mogi.  Relations between the Eruptions of Various Volcanoes and the Deformations of the Ground Surfaces around them , 1958 .

[18]  Yousuke Miyagi,et al.  Surface deformation caused by shallow magmatic activity at Okmok volcano, Alaska, detected by GPS campaigns 2000–2002 , 2004 .

[19]  Zhong Lu,et al.  Synthetic aperture radar interferometry of Okmok volcano, Alaska: radar observations , 2000 .

[20]  F. Sigmundsson,et al.  Comment on " Volume of magma accumulation or withdrawal estimated from surface uplift or subsidence, with application to the 1960 collapse of Kīlauea volcano" by P. T. Delaney and D. F. McTigue , 2000 .

[21]  Timothy Masterlark,et al.  Magma intrusion and deformation predictions: Sensitivities to the Mogi assumptions , 2007 .

[22]  Jan-Peter Muller,et al.  Surface movements of emplaced lava flows measured by synthetic aperture radar interferometry , 2001 .

[23]  Zhong Lu,et al.  The postseismic response to the 2002 M 7.9 Denali Fault earthquake: Constraints from InSAR 2003-2005 , 2009 .

[24]  Zhong Lu,et al.  Source model for the Mw 6.7, 23 October 2002, Nenana Mountain Earthquake (Alaska) from InSAR , 2003 .

[25]  F. A. Seiler,et al.  Numerical Recipes in C: The Art of Scientific Computing , 1989 .

[26]  Christophe Delacourt,et al.  Post‐eruptive deformation associated with the 1986–87 and 1989 lava flows of Etna detected by radar interferometry , 1997 .

[27]  Peter W. Webley,et al.  Eruption of Alaska Volcano Breaks Historic Pattern , 2009 .

[28]  Theory of Linear Poroelasticity with Applications To , 2000 .

[29]  Robert M. Owen,et al.  Statistical Tests for Closure of Plate Motion Circuits (Paper 7L7161) , 1987 .

[30]  D. Richter,et al.  Catalog of the historically active volcanoes of Alaska , 1998 .

[31]  Zhong Lu,et al.  Magma supply dynamics at Westdahl volcano, Alaska, modeled from satellite radar interferometry , 2003 .

[32]  Rowena B. Lohman,et al.  Some thoughts on the use of InSAR data to constrain models of surface deformation: Noise structure and data downsampling , 2005 .

[33]  Zhong Lu,et al.  Satellite radar interferometry measures deformation at Okmok Volcano , 1998 .

[34]  Zhong Lu,et al.  Interferometric synthetic aperture radar study of Okmok volcano, Alaska, 1992-2003: Magma supply dynamics and postemplacement lava flow deformation , 2005 .

[35]  J. Freymueller,et al.  Deformation of Okmok Volcano Associated with its 2008 Eruption , 2008 .

[36]  M. Biot.  Thermoelasticity and Irreversible Thermodynamics , 1956 .

[37]  S. Jónsson,et al.  Modeling volcano and earthquake deformation from satellite radar interferometric observations , 2002 .

[38]  Daniel Dzurisin,et al.  Continuing inflation at Three Sisters volcanic center, central Oregon Cascade Range, USA, from GPS, leveling, and InSAR observations , 2009 .

[39]  Zhong Lu,et al.  Estimating lava volume by precision combination of multiple baseline spaceborne and airborne interferometric synthetic aperture radar: the 1997 eruption of Okmok volcano, Alaska , 2003, IEEE Trans. Geosci. Remote. Sens..

[40]  Mark Simons,et al.  Deformation and seismicity in the Coso geothermal area, Inyo County, California: Observations and modeling using satellite radar interferometry , 2000 .

[41]  John J. Dvorak,et al.  Volcano geodesy: The search for magma reservoirs and the formation of eruptive vents , 1997 .