J R Kayal

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Challenges in Observational Seismology with
Reference to the Indian Ocean
J R Kayal Geological Survey of India Kolkata e-mai
l jr_kayal_at_hotmail.com
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GLOBAL SEISMIC NETWORKS

• WWSSN (USGS) and ESSN (USSR and allied
  countries) since 1960s (Short period Long
  period Analog Seismographs)
• IDA (International Deployment Accelerometers,
  digital systems) since 1970s.
• GDSN (24 bit Digital Broad Band, USGS, FDSN and
  IRIS), since 1980s.
• GEOSCOPE (French Program) since 1990s.

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World Seismicity (1960-2005) and Plate Bounadries
Red Divergent, Yellow Convergent, Blue
Transform, White Diffuse
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Seismic Wave Propagation of the 2004 Sumatra
earthquake
www.geol.binghamton.edu/faculty/jones
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Seismic Wave Propagation of the 2004 Sumatra
earthquake
www.geol.binghamton.edu/faculty/jones
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WWSSN seismogram of the 1964 Alaska Mw 9.2
earthquake
GSN seismogram of the 2004 Sumatra-Andaman
earthquake Mw 9.3
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Source Mechanisms of the 2004 and 2005 Earthquake
Sequences (Lay et al., 2005)
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CMT SOLUTIONS OF THE 2004 SUMATRA EARTHQUAKE
SEQUENCE
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Location of Digital Broadband stations
Legend BB stations RefTek GDSN
stations STS-2 HYB STS-1
2nd Jan 2006
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Band Pass
Seismograms of the 2004 main shock at different
BB stations, India
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Vertical Acceleration recorded at VISK (2004
Main Shock)
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Vertical Acceleration recorded at VISK (2004
Main Shock)
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Vertical Acceleration recorded at BLSP, Jan 2
2005 Aftershock
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Vertical Acceleration recorded at BLSP, Jan 2
2005 Aftershock
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Love Wave Transverse Component
Rayleigh wave
Band-pass filtered (0.0078-0.00156 Hz) BB trace
of 2nd Jan 2005 (Mw 6.3) at BLSP
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Waveform comparison of the 2004 main shock and
the 2ndJan 2005 aftershock
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Moment rate spectrum of the main shock the
aftershock
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Sumatra Aftershock Sequence b-value
Maximum Likelihood b-value 1.34
Least Square Fit b-value1.32
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Seismograms showing Acceleration, Velocity
Displacement
Aftershock Investigation at Port Blair
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GSI Temporary Network for Aftershock Investigation
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Three component seismograms of an aftershock
recorded in Andaman Islands.
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Aftershocks Recorded till March 16, 2005
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1. Aftershocks located by the Global Network (USGS)
2. Aftershocks located by the GSI Temporary Network.

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Fault plane solutions of the Aftershocks recorded
by the GSI Temporary Network
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Real Time Seismic and GPS Monitoring Network
(Future Plan)
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Tide gauge network for Indian Coastline
Kolkatta
Paradip
Mundra
Kandla
Mumbai
Pipvav
Kakinada
JNPT
Machillipattnam
Goa
Ennore
NMPT
Chennai
Nagappattinam
Cochin
Tuticorin
Kolachal
Kanyakumari
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communication for East and West coast of India by
2005-2007
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Sea Level Monitoring Stations
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HF Radar-based Monitoring of Surface Current and
Wave
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Challenges in ForecastingEARTHQUAKES
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Microseismicity in NE India
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Resistivity Precursor Study in NE India
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Resistivity precursor Study (Shillong) ( Kayal
and Banerjee, 1988, JGI )
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( Arur et al., 1986 )
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( Kayal, 1991, PAGEOPH )
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( Kayal, 1991, PAGEOPH )
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( Kayal, 1991, PAGEOPH )
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Kayal, 1991, PAGEOPH
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PRECURSOR EARTHQUAKE SWARM ( 1984 CACHAR
EARTHQUAKE, M 5.8 )
( Gupta, 1987 )
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PRECURSOR EARTHQUAKE SWARM ( 1988
INDO-BURMA EARTHQUAKE, M 7.3 Predicted )
( Gupta and Singh, 1989 )
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PRECURSOR RADON CONTENT IN WELL WATER ( 1988
INDO-BURMA EARTHQUAKE, M 7.3 )
JULY
AUGUST 1988
( Kharsiing, A. D., NEC, Pers. Comm. 1988 )
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( De and Kayal, 2003, BSSA )
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MICROEARTHQUAKE STUDY IN SIKKIM, EASTERN HIMALAYA
(De, 2000)
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MICROSEISMICITY MAP OF SIKKIM HIMALAYA
( After De and Kayal, 2004 )
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5.7
Temporal changes in gravity at selected stations
in Gangtok area, Sikkim.
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Thank you !