GROUND DEFORMATION DUE TO STEAM CAP ......Sentinel-1 InSAR successfully captures deformation at...
Transcript of GROUND DEFORMATION DUE TO STEAM CAP ......Sentinel-1 InSAR successfully captures deformation at...
GROUND DEFORMATION DUE TO STEAM CAP PROCESSES AT REYKJANES, SW-ICELAND: EFFECTS OF GEOTHERMAL
EXPLOITATION INFERRED FROM INTERFEROMETRIC ANALYSIS OF SENTINEL-1 IMAGES 2015-2017
Mylรจne Receveur (1), Freysteinn Sigmundsson(1), Vincent Drouin(1,2), Michelle Parks (3)
(1) Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland(2) National Land Survey of Iceland, Akranes, Iceland
(3) Icelandic Meteorological Office
[email protected] Master project
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Highlightsโข Time series analysis from 2015 to 2017 using
Interferometric analysis of C-band Sentinel-1A and Sentinel-1B data
โข Determination of the parameters for the deformation source using probabilistic inversion
โข Models of deformation processes, considering pressure/temperature and production data
2Source :Mylene Receveur
Source :European Space Agency (ESA)
Source : Mylรจne Receveur
Introduction Data Time series analysis Modeling Interpretation Conclusion
โข High temperature geothermal system
โข 17 production and 5 injection wells in 2015-2017
โข Commissioning of the 100 Mwe power plant in 2006
Average yearly next extraction of geothermal fluid 1970-2016 (Vatnaskilreport, 2017)
Pre
ssu
re (
ba
r) 2
00
6-2
01
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3Source: HS-Orka; Thorvaldsson & Arnarsson, Vatnaskil report, 2017; Khodayar et al., 2016
Introduction Data Time series analysis Modeling Interpretation Conclusion
2005-2016 Inferred cumulative vertical displacement: -0,26 mContraction towards the center of deflation: 0.14 m.
Envisat track 173 Envisat track 138
2005-2008
Envisat T173: -33mm/yr
Envisat T138: -28 mm/yr
Parks et al. (2018)
TSX track T26 TSX track T1102009-2016
TSX T26: -24 mm/yr
TSX T110: -21 mm/yr
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Phase change in range (rad)
Phase change in range (rad)
Introduction Data Time series analysis Modeling Interpretation Conclusion
a) Geometry for ascending and descending near-polar orbits.
b) Projection of heading h and LOS vectors l onto the ground plane (Wortham, 2014).
๐ท๐๐ ๐๐๐๐๐๐๐ ๐155
๐ด๐ ๐๐๐๐๐๐๐ ๐16
๐๐ฟ๐๐ = โ าง๐ โข เดค๐ข
เดค๐ข๐16 = [โ0.545 0.123 0.830]
เดค๐ข๐155 = [0.605 0.123 0.787]
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Sentinel-1 mission: two satellites, two tracks
โช 104 and 107 Single Look Complex images from T16 and T155 between October 2014 โ January 2018
โช 1 image every 12 days, 5 x 20 m resolution
โช Processing: ISCE software
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Introduction Data Time series analysis Modeling Interpretation Conclusion
โช40 interferograms
โช804 days
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โช47 interferograms
โช942 days
Perpendicular baseline
o S1Ao S1B
Introduction Data Time series analysis Modeling Interpretation Conclusion
Velocity mapsโชResolution:
40 x 40 m
โชSub-circular subsidence bowl centered on the most productive area (Gunnuhver hot spring)
โชLinear deformation: 16 mm/yr in the satellite LOS
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Time series analysis for a set of point situated in the center of the most deforming area (black squares):
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Introduction Data Time series analysis Modeling Interpretation Conclusion
Decomposition into near-vertical and near-east displacement components
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๐๐ =๐๐ด + ๐๐ท
1.617 ๐๐ธ =๐๐ด โ ๐๐ท
โ1.149
Near-eastNear-vertical
-25 mm/yr
+4 mm/yr
-10 mm/yr
(mm/yr) (mm/yr)
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Introduction Data Time series analysis Modeling Interpretation Conclusion
Horizontal Okada sill with uniform closing and contracting penny shaped crack
โชInput: LOS average velocity maps
โชContraction of a rock body under pressure change in a homogeneous, isotropic and elastic half-space
โช5 model parameters
โชResults: source at 1 km depth closing by a constant rate of 4 cm/yr or a volume change โ๐ = 0,9 โ 105๐3/๐ฆ๐
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-0,04 [ -0,06; -0,02]1531 [979; 1969]1357 m [666; 2156]
1161 1097; 1193700 680; 730
โ9.96 โ10,0;โ8,5] ร 10โ5
Introduction Data Time series analysis Modeling Interpretation Conclusion
Relation between deformation sources and geological structure
(modified from Friรฐleifsson et al., 2014; Khodayar et al., 2016)
Vertical displacement map
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Reservoir volume : 3,8 ๐๐3
Average reservoir thickness : 2 kmMicro-scale porosity: 15%Steam cap thickness: 300-400 mSteam cap volume: 0,6-0,8 ๐๐3
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๐๐ฃ =๐๐ฃ
๐๐๐๐ +
๐๐ฃ
๐๐๐๐ = ๐ฃ๐ผ๐๐ โ ๐ฃ๐๐๐
Introduction Data Time series analysis Modeling Interpretation Conclusion
๐ฃ โถ ๐ ๐๐๐๐๐๐๐ ๐ฃ๐๐๐ข๐๐๐: ๐๐๐๐ ๐ ๐ข๐๐๐: ๐๐๐๐๐๐๐๐ก๐ข๐๐๐ผ: ๐ถ๐๐๐๐๐๐๐๐๐๐ก ๐๐ ๐กโ๐๐๐๐๐ ๐๐ฅ๐๐๐๐ ๐๐๐๐: ๐๐๐๐๐ฅ๐๐๐ ๐๐๐๐-๐๐๐๐ ๐ก๐๐ ๐๐ฅ๐๐๐๐ ๐๐๐ ๐๐๐๐๐๐๐๐๐๐๐ก
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Cumulative volume change 2005-2017
โ๐๐ก๐๐ก(2005โ2017) = โ3,9 ร 106๐3
1) Pressure change
2) Cooling within a horizontal layer
3) Delayed rock compaction
๐๐ฃ =๐๐ฃ
๐๐๐๐ +
๐๐ฃ
๐๐๐๐ = ๐ฃ๐ผ๐๐ โ ๐ฃ๐๐๐
Introduction Data Time series analysis Modeling Interpretation Conclusion
In a Penny shaped crack
โ๐ =ยต
2๐3โ๐
โ๐๐๐๐ถ= โ0,7 ร 105๐3/๐ฆ๐
with ๐ = 700 ๐
ยต = (1 โ 20) ๐บ๐๐
โ๐ = 0,1 ๐ก๐ 2 ๐๐๐/๐ฆ๐
โ๐ = 0,15 ๐๐๐/๐ฆ๐ if ยต = 1,5 ๐บ๐๐
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โ๐ = 0,3 MPa in 2 years(-0,15 MPa/yr)
Introduction Data Time series analysis Modeling Interpretation Conclusion
In the Okada layerโโ = ๐พ๐ผโโ๐
= โ0,04 ๐/๐ฆ๐With ๐พ๐ผ = (1 โ 5) ร 10โ5 ยฐ๐ถโ1
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If โ๐ = โ4 ยฐ๐ถ/๐ฆ๐โ = 200 ๐ก๐ 1000 ๐
If โ = 400 ๐โ๐ = โ10 ๐ก๐ โ 2ยฐ๐ถ/๐ฆ๐
1) Pressure change
2) Cooling within a horizontal layer
3) Delayed rock compaction
๐๐ฃ =๐๐ฃ
๐๐๐๐ +
๐๐ฃ
๐๐๐๐ = ๐ฃ๐ผ๐๐ โ ๐ฃ๐๐๐
โ = 600 ๐
โ๐2009โ2015=30ยฐC
At 925 m b.s.l
Non-linear relationship between pressure and volume change
Change in isothermal compressibility (steam zone)
โ๐ = ๐โ๐๐
Introduction Data Time series analysis Modeling Interpretation Conclusion
๐ = ๐ ร ๐๐โ๐๐๐ท๐โ๐
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๐ = ๐ ร ๐๐โ๐๐ท๐โ๐
1) Pressure change
2) Cooling within a horizontal layer
3) Delayed rock compaction
๐๐ฃ =๐๐ฃ
๐๐๐๐ +
๐๐ฃ
๐๐๐๐ = ๐ฃ๐ผ๐๐ โ ๐ฃ๐๐๐
Source: Thorvaldsson & Arnarsson, Vatnaskil report, 2017; Khodayar et al., 2016)
โ๐๐ก๐๐ก(2005โ2017) = โ๐๐๐๐ ๐๐๐ฃ๐๐๐+ โ๐๐ ๐ก๐๐๐ ๐๐๐ = โ2,6 ร 106 โ 1,3 ร 106 = โ3,9 ร 106๐3
Conclusion
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โชSentinel-1 InSAR successfully captures deformation at Reykjanes using only two years of data. Ideal location at Reykjanes (flat & vegetation free area)
โชDecrease in the rate of volume change :โช 2006-2009: -7.3 x 105 m3/yrโช 2009-2016: -1,5 x 105 m3/yrโช 2015-2017: -0,9 x 105 m3/yr
โชMigration of the modelled source from about 2,2 km to 1 km depth
โชChange in subsidence pattern
โชCombination of pressure, temperature and compressibility change in steam cap can explain 2015-2017 deformation
FutureโชNumerical modeling of deformation processesโชUse geodetic studies to guide reinjection and
preservation of the steam cap
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Thank you !QUESTIONS ?
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Clifton, A., 2003. Fracture populations on the Reykjanes Peninsula, Iceland: Comparison with experimental clay models of obliquerifting. In: Journal of geophysical research, Vol, 108, NO. B2, 2074, doi:10.1029/2001JB000635
Drouin, V., Sigmundsson, F., Verhagen, S., Ofeigsson, B.G., Spaans, K., Hreinsdottir, S., 2017. Deformation at Krafla and Bjarnaflaggeothermal areas, Northern Vocanic Zone of Iceland, 1993-2003. In: Journal of Volcanology and Geothermal Research 344. 92-105.
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Im, K., Elsworth, D., Guglielmi, Y., Mattioli, G.S., 2017. Geodetic imaging of thermal deformation in geothermal reservoirs โproduction, depletion and fault reactivation. In: Journal of Volcanology and Geothermal Research (unpublished). 13p
Khodayar, M., Nielson, S., Hickson, C., Gudnason, E.A., Hardarson, B.S., Gudmundsottir, V., Halldorsdottir, S., Oskarsson, F., Weisenberger, T.B., Bjornsson, S., 2016. The 2016 Conceptual Model of Reykjanes Geothermal System, SW Iceland. ISOR Report. Project No: 15-0230. 110p
Okada, Y. 1985. Surface deformation due to shear and tensile faults in a halfspace, Bull. Seismol. Soc. Am., 75, 1135โ1154.
Parks, M., Sigmundsson, F.,Sigurdson, O., Hopper, A., in review. InSAR Analysis of the Western Reykjanes Peninsula: 2003 to 2016. Draft report.
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