Annual Report 2000-2001
The Seismicity Programme has been evolved with
a view to understand the earthquake processes/mechanism related
to the Indian Lithosphere, their recurrence interval and their
manifestation on the surface towards developing knowledge
and techniques for hazard mitigation. During the last few
years, a good infrastructure has been created at various identified
locations and lab facilities have been established at different
institutions. New groups, especially from Northeast were infused
to take up the earthquake related studies. With the increased
interest of the scientific community in the programme, new
geographical areas like Delhi region, Bihar plains and peninsular
shield were also taken up for carrying out integrated studies.
Special initiatives were launched for Northeast region and
Modern seismological observations have been set up at selected
The strong motion Array of Delhi region has
generated a good data set on Chamoli earthquake. The data
have been used to carry out a study for prediction of ground
motion in Delhi due to future large earthquakes in Chamoli
region. Strong motion data, generated from the Himalaya region,
have also been used for designing earthquake resistant structures.
Most of the Broadband observatories, established under World
Bank Project, in peninsular region have become operational.
Under a project entitled" Imaging of seismic faults in
Killari and adjoining region of Maharashtra, a seismological
observatory is being set up at Nanded. Efforts are being made
to instrument a few selected buildings in Delhi to get data
on the structural response behavior and soil characteristics.
The data so generated will be of great value for design of
A project database, established at WIHG, Dehradun has started
functioning. In addition, a modern telemetered seismic system
has been set up at Tejpur, Assam with the support from DST
to NGRI. A TL dating facility has also been set up at Manipur
University. A project on "Upgradation and modernization
of Shake Table Facility at Department of Earthquake Engineering",
University of Roorkee is being implemented. The facility will
help in earthquake disaster mitigation research related studies.
A project has been sanctioned to National Informatics Centre
Services Inc. (NICSI), New Delhi to link the seismological
observatories and National Seismological Data Centre (NSDC),
IMD through V-SATs. The project is being implemented in close
coordination with IMD and NICSI. Indigenous development of
of geo-instrumentation has also been initiated. In this direction,
a project was sanctioned to CSIO, Chandigarh to design and
develop 16-bit and 20-24 bit seismographs. Also, a proposal
to design and develop a multi-element telemetry system at
Bhabha Atomic Research Centre for Koyna region is under consideration.
Two state-of-art seismic telemetry systems, procured for Khandwa
and Koyna-Warna region, are under testing and will be installed
Achievements under the completed projects
- In a project entitled "Seismic Hazard in the Himalayas
and North-East India Regions", following achievements
have been reported:
Moment magnitude catalogs have been complied for the different
time periods and magnitude ranges for the Himalaya and Northeast
India (areas covering longitude 69-830 E & latitude
25-360 ) as detailed below:
- Catalog of large earthquakes for the period 1762-1999.
- Catalog of moderate earthquakes for the period 1950-1999.
- Catalog of small earthquakes for the period 1964-1999.
From the above catalogs frequency-magnitude
relationship has been established.
It has been reported that there is a Quiescence of Major earthquakes
Also it has been concluded that the Wadati-Benioff Zone has
a predominant down-dip tensional stress regime and the subduction
in the Indo-Burma region is possibly active.
- In a project entitled "Estimation of Moment Rate
Function in Himalayas and Koyna Regions using Empirical
Green's Function" Source time functions of selected
events has been estimated as empirical Green's functions.
The source time function for the Koyna events (M=3.1) appears
to be unipolar Pulse, while for Chamoli event (M=6.5) it
is relatively simpler and represent simple rupture process
as expected from the rupture of earthquake of such size.
- The project entitled "Neotectonic and Palaeoseismic
Studies in Katchchh and adojoining Areas" provides
information for better understanding of tectonic aspects
of Kachchh Mainland. Following are the specific achievements:
- The Karol Hill Fault Zone (KHFZ) has experienced at
least three major events of uplifts, one coinciding
with the inversion event, which resulted in the large-scale
drainage reversal and other, two post dating it. Also,
chronology of the later is inferred on the basis that
three individual paired terraces are carved in early
Pleistocene miliolite rocks exposed within the KHFZ.
- The morphometric analysis of the KHFZ shows that Krol
Hill Fault is one of the most active faults in the Kachchh
- Studies related to the genesis of Allah indicate that
the faulting involved was of normal nature.
- The seismic hazard analysis indicates the presence
of four major seismo-active zones in Kachchh region.
- In a project entitled "Active tectonics of the Western
Gangetic Plains including the Piedmont Zone" following
achievements have been reported.
- Four major types of landforms - Aeolian Plain, Piedmont,
Plains associated with rivers and Interfluves are identified
from the area.
- A soil chronoassociation with five QGN1 -QGN5 with
ages of < 500 years, > 500 years, 2.5 ka, ~5 ka
and 8.5 ka respectively has been recognized from the
- Four tectonic blocks i.e. Solani, Khoh, Solani-Ganga,
Upper Ganga-Yamuna, Lower Ganga-Yamuna and Ganga-Ramganga
blocks are deciphered.
- Using a soil-geomorphic approach developed at UOR,
significant neotectonic movements have been inferred.
For example- (i) uplift of Lower Ganga-Yamuna, Ganga-Ramganga
and Upper Ganga-yamuna blocks took place at about 8.5
ka, 5 ka and 2.5 ka respectively, (Ii) Westward tilting
of the Ganga-Ramganga block took place at about 2.0
ka (?) and 1 ka leading to shifting of the Ganga river
in the same direction (iii) these dates give a recurrence
interval of 1000-3500 years for major movements in the
- A cold and dry climate prevailed in the area from
early Holocene to about 6000 B.P. and resulted in accumulation
of pedogenic salt and calcrete in the soil. Later a
warm and water climate accompanied by improved drainage
caused leaching down of salts and calcrete from the
soil in certain areas.
Setting up of Earthquake Risk Evaluation
A proposal to establish an Earthquake Risk
Evaluation Centre (EREC) in Northern India has been approved
by the Committee of Secretaries (COS) at its meeting held
on September 19th, 2000. The EREC will primarily concentrate
its activities in northern India, which is contiguous to the
Himalaya and forms a part of global seismic belt. The fast
population growth, changing land use/land cover and economic
development in the Himalaya and its contiguous region demands,
a very focussed attention.
The Centre will undertake/promote all tasks related to earthquake
risk evaluation. The specific outputs are
- To provide earthquake risk related knowledge products
for designated areas: earthquake hazard, vulnerability as
well as risk maps and figures.
- To develop suitably distributed Information Systems for
ready collation of primary data from different national
sources, their archival, availability and retrieval, their
quality indices, and also develop advance level integrated
- To develop a vibrant user Interface in order to constantly
interact with various agencies involved in risk mitigation
as well as with local communities with the express objective
of a) communicating to them the knowledge products of the
centre and their implications, and b) to continually reappraise
the relevance and usability of these products, through specially
designed feedback activities.
- To articulate well considered legislative and regulatory
measures for effective mitigation of risk, and advise/request
appropriate agencies to implement these.
- To catalyze development of evermore-effective risk assessment
and mitigation approaches and systems by sponsoring such
programs that may be warranted in the light of new emerging
national priorities as well as new developments globally
in exploiting up-to-date S & T systems towards mitigation.
An Indo-Italian Workshop on "Seismic Risk
Evaluation - Methodology and applications" is being organized
at NGRI, Hyderabad. The over all idea of this workshop is
to identify certain collaborative projects of mutual interest
in the field of seismic risk evaluation. The workshop also
includes a field visit to Jabalpur, which has been identified
for carrying out a sample survey for microzonation studies.
Under the Jai Vigyan Technology Mission project on Natural
Hazard Assessment in Himalaya, activities have been initiated
to set up the Geophysical Research Laboratory (GRL), Allahabad.
A special volume on seismicity, containing the research papers
emanated from the various DST supported projects is being
published through Indian Geological Congress.
The first issue of the newsletter containing scientific developments
taking place globally and also contributions from the projects
supported under the programme has been brought out.
Short Term Courses/Workshop
- An international workshop on "Seismic Electromagnetics
and Space Sciences" was organized at R.B.S. College,
Agra during Dec. 19-21, 2000. About 90 participants from
India and abroad participated.
- A training course is being organized on "Broad Band
Seismographs" at India Meteorological Department, New
Delhi. About 30 participants, from the institutions/universities,
engaged in operation and maintenance of BB observatories
are expected to attend.
- A training course on "operation and maintenance of
strong motion instruments" is being organized at Department
of Earthquake Engineering, University of Roorkee, Roorkee.
About 20 participants, from different organizations, are
expected to attend the course.