SEISMOLOGY AND GEOSCIENCES (SAGE) SCHEME

Under the Seismology and Geosciences (SAGE) scheme of the Ministry of Earth Sciences (MoES), several important programmes and activities are under implementation by MoES with its network of institutions. Few important programmes are:

1. Seismological monitoring and microzonation:

• • The National Centre for Seismology (NCS) in New Delhi is an attached office of MoES. It operates and maintains National Seismological Network (NSN). NSN consists of 115 seismological observatories spread across the country.
  • NCS maintains a round-the-clock watch of seismic activity in the country. A Central Receiving Station (CRS) at NCS receives real-time digital waveform data from field stations. This data is used to determine preliminary earthquake source parameters.
  • Another important activity implemented by the NCS is microzonation. It is a site-specific study that provides a more realistic and reliable representation of ground motion characteristics. It involves sub-division of a region into zones that have relatively similar exposure to various earthquake-related effects.

2. Geodynamics and surface processes: This program addresses the modelling of crustal, coastal, geohydrological and atmospheric processes to assess wave climate, hydrodynamics and sediment transport along selected stretches of the Indian west coast. It aims to understand the impact of coastal structures.

• • Research under this program is categorized under the following four themes:
    • Crustal processes: It includes studies related to deep internal processes during the Earth’s history; cover sequences in the form of sedimentary deposits and surface processes and neo/active tectonics relative to the present-day seismicity and land distribution the Western Ghats.
    • Coastal processes: It includes studies of beach morphodynamics and nearshore sediment transport, modeling of coastal processes and coastal, estuarine and inner shelf sedimentation.
    • Natural resources and environmental management: It includes studies on critical zone characteristics of selected watersheds of Indian rivers, evaluation of hydrological and biogeochemical aspects of peninsular river basins and generation of geo-environmental inputs for natural resources management planning and development activities.
    • Natural Hazard: It addresses natural hazards such as landslides including land subsidence, earthquake, flood, drought, coastal erosion, lightning, sea-level rise, storm surge and tsunami inundation in the Western Ghats region.
  • The National Centre for Earth Science Studies (NCESS), Thiruvananthapuram, implements the core R&D under this program.
  • A national network project called Submarine Groundwater Discharge (SGD) is also being implemented under this program. It will help to quantify the amount of fresh groundwater discharge into the Bay of Bengal and Arabian Sea through coastal aquifers.

3. Indian Ocean: Deep ocean observations and dynamics of lithospheric evolution (IODP and geoid low):

• • The MoES joined the International Ocean Discovery Program (IODP) consortium in 2009 as an Associate Member through an MoU with National Space Foundation, USA. Since joining the IODP consortium, Indian scientists have been participating in IODP expeditions each year for scientific research in different facets of scientific drilling in a variety of geological settings around the world.
  • National Centre for Polar and Ocean Research (NCPOR), Goa serves as the nodal office for IODP-India.
  • A geoid is a hypothetical equipotential surface that explains the geometrical irregularities of the Earth. It approximates to the mean sea level. Deviations of the geoid from an idealized hydrostatic ellipsoid are known as geoid anomalies. Under this program, it is planned to achieve a comprehensive understanding about the nature, source and cause of the geoid anomalies in the region through integrated interpretation and to develop a better understanding about the geodynamic evolutionary history, mantle processes, etc.
  • The Indian Ocean Geoid Low (IOGL), centred near to south of Sri Lanka, is the largest geoid low in the globe.

4. Scientific deep drilling in the Koynaintraplate seismic zone, Maharashtra: to understand the mechanism of recurrent earthquakes in the Koyna region.

5. Seismicity and earthquake precursors: It is a research-driven programme with a perspective to provide impetus to the studies related to seismology, which provides thrust to the earthquake‐related studies and also to generate inputs for earthquake disaster mitigation. It aims to generate long‐term and comprehensive multi‐parametric geophysical observations in seismically active areas, towards establishing possible relationships between earthquake precursory phenomenon and the earthquake generation processes.

6. Setting up a facility for geochronology:

• • Geochronology is the study of the age of rocks, fossils and sediments.
  • MoES is setting up ageochronology facility at Inter University Accelerator Centre (IUAC), New Delhi to cater to the need of geoscientists of the country. The geochronology facility has the mandate of developing an internationally-competitive centre for geochronology and isotope geochemistry that will facilitate generation of quality isotopic data for geochronological and isotopic fingerprinting.