1. Present-day Crustal deformation around the eastern part of Himalayan arc in the Shillong plateau area using PSInSAR technique
Md Rashedul Islam, Kuo-En Ching, Chung-Pai Chang, Jiun-Yee Yen, Ruey-Juin Rau
Monitoring and Analysis of Crustal Deformation Lab,
Department of Geomatics, NCKU
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2. Contents The Shillong plateau, Meghalaya, NE India Research objectives
Geological background of the Shillong plateau
ALOS InSAR data for study
StaMPS PSInSAR method
Results and Discussion
PS LOS velocity vs published GPS velocity
Conclusion and Future works

3. The Shillong Plateau- a seismogenic zone in NE india
Study area is
25°57' to 26°77′N
lat and 91°74' to
92°38' E lon
China
1950
The length is 111km and width is 37 km
Himalaya
2015
Study Area
1934 A
1833
1897
Myanmar
Shillong Plateau
India
Bangladesh
Very high plateau, densely populated and seismically active zone
Bird’s eye view of
of Study Area
Origin related to the collision of India and Eurasian plate
Place of great earthquake events (1897) and active faults like dauki fault

4. Research objectives
Present-day crustal deformation, Earthquake potential, and seismic hazards assessment in the study area.

5. Geology of the Shillong Plateau
Shillong plateau is separated from the India by Tertiary Ganges-Brahmaputra alluvium and
Cretaceous Rajmahal Volcanics rocks (Nandy, et al., 1980).
It is an E-W trending oblong horst block uplifted above the Bangladesh plains.
1950
Earthquake(8.2)
1934
1897
Fig. 2: Tectonic map showing the major features around Shillong Platea. Brahmaputra Fault,
DT: Dapsi thrust, OF: Oldham fault, Kopili and Dauki Fault.(Credit:Baruah and Hazarika)

6. ALOS InSAR Data For Study
ALOS Palsar data from October 2006 to January 2011
Assending type 20 images
ALOS_P498_F510_Shillong_Meghalaya (FBS,FBD)
Master date:
498_510
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7. Research Methodology StaMPS PSInSAR Method and Image processing:
StaMPS (Stanford Method for Persistent Scatterers) is a software package that implements an InSAR persistent scatterer (PS) method. StaMPS also includes a small baseline method and a combined of PS-SB InSAR method. The original development of StaMPS was undertaken at Stanford University, CA, USA.
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8. Fig.4:StaMPS-InSAR Image Processing Flowchart

9. Results and Discussion:
13th July 2007
28th Aug 2007
13th Oct 2007
28th Nov 2007
13th Jan 2008
28h Feb 2008
14th Apr 2008
30th Aug 2008
30th Nov 2008
18th Jan 2010
5th Mar 2010
21th July 2010
21th Oct 2010
21th Jan 2011
MASTER DATE
Fig.5: 14 Differential Interferograms of Shillong, Meghalaya study area
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10. Fig.6: Enlarge view of the Master ifg: 30th Nov 2008
After StaMPS InSAR
processing 14 differnetial
Interferograms including
master were produced
Fig.6: Enlarge view of the Master ifg: 30th Nov 2008
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11. StaMPS PS LOS velocity (mm/y)
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12. Fig.8: Changes of PS LOS velocity showing Crustal deformation
Bhutan Himalaya
Subduction zone of Himalaya N
Brahmaputra Fault
Dauki Fault (100km)
Fig.8: Changes of PS LOS velocity showing Crustal deformation

13. LOS deformation velocity Vs published GPS horizontal velocity
LOSV= -25 to -65 mm/y
SH B GPSV= 5 mm/y N
BHH B GPSV= 23 mm/y S
AS B GPSV= 13 tp 19 mm/y N
THB GPSV= 31 mm/y S
LOSV= +25
to + 65 mm/y
Flight dir.
LOS Vel
LOSV= -25 to -55 mm/y
GPS Hor Vel
Vernant et.al., 2014
Fig.9:Horizontal Convergence rates between southern Tibet and India increase eastward across the Himalaya from 18 mm/yr in eastern Nepal [Ader et al., 2012] to 31 mm/yr in eastern Assam.[Burgess et al., 2012].

14. Conclusion and Future Works
After StaMPS PSInSAR processing we got clear crustal deformation signal of our north and south study area. Based on this preliminary results further study need to be conduct toward west and east side of our two study area. Finally, we can advance in further research like inter seismic slip deficit deformation modeling along Dauki and other active major faults to estimate future earthquake potential and to asses seismic hazards.
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15. Thanks For Your Attention
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