Port Blair, Mar 29: The Indian Institute of Geomagnetism is a premier research organization under Department of Science and Technology, Government of India, and is involved with research on Geomagnetism and allied fields.
The Institute was reconstituted from the erstwhile Colaba-Alibag Observatories functioning under the India Meteorological Department and became an autonomous organization under the Department of Science and Technology, Government of India, in 1971.
Its Headquarters is located at Navi Mumbai. Under its fold, it currently has two Regional Centres and twelve magnetic observatories located across the length and breadth of the country. Of these, the Colaba-Alibag observatories have been providing uninterrupted data for nearly 175 years.
The institute archives and exploits data from these observatories to derive valuable science. The short and long term variations in the geomagnetic field at a location are fully captured by monitoring the magnetic field recorded in the vertical (Z), north-south (N-S), and east-west (E-W) directions together with the determination of its inclination and declination. The long term changes in the Earth’s magnetic field, also known as secular changes, essentially reflect the dynamics of the Earth’s interior. While, the short period excursions relate to current systems above the Earth’s surface at different heights caused by the solar-terrestrial interaction. Therefore, several geomagnetic indices corresponding to varied phenomena in the Geo-Space environment are derived from these geomagnetic observations.
Thus, variations of the geomagnetic field have great implications to understand the inter-connectivity between the Sun, the Earth and the intervening interplanetary medium. Our studies have several important applications such as monitoring & forecasting the Space weather, deciphering Climate variations and finally Earthquake precursory research. This indeed is seamless integration of science that is excellent with that of relevance.
The 26th December, 2004 tsunami caused by an earthquake in the west coast of Sumatra, Indonesia wreaked havoc and resulted in unprecedented loss of lives and property in the islands of Andaman & Nicobar and elsewhere. Taking note of the immense magnitude of such natural hazards, the Department of Science and Technology, Govt of India entrusted the Indian Institute of Geomagnetism (IIG) with the responsibility of setting up a Multi-Parametric Geophysical Observatory (MPGO) in this region and Shillong in the Northeast to monitor these disasters and also conduct research on the possible precursory mechanisms.
It is believed that earthquakes leave precursory signatures in different seismogenic parameters prior to their occurrence. Thus, monitoring of electromagnetic emissions in varied frequency bands, variations in GPS signals, water table fluctuations, Radon gas emissions from micro-fractures etc. during an earthquake preparatory phase has conceptualised the establishment of the MPGO at Port Blair.
This Multi-Parametric Geophysical Observatory (MPGO) at Shoal Bay, Port Blair hosts a variety of sophisticated instruments to monitor both long and short term excursions in the Earth’s Magnetic field at varied frequencies using state-of-the-art Overhauser, Induction coil and Fluxgate magnetometers. These equipment record signals related to processes of the Earth’s interior and the ionospheric phenomena.
The MPGO would house hi-fidelity instruments by way of Very Broad Band Seismometer, Ground Accelerometer and GPS to document both vertical and horizontal components of the seismic disturbances. The attendant or induced water level changes and Radon Gas emissions will also be monitored continuously. In addition, various meteorological parameters are proposed to be recorded at the MPGO. Based on analyses of these observations, several precursory seismogenic signals can be distilled.
This Multi-Parametric Geophysical Observatory offers a unique opportunity to comprehend and decipher the coupled nature of the lithosphere-atmosphere-ionosphere-magnetosphere system leading towards development of an Integrated Precursory Signals System (IPSS) to mitigate natural disasters of varied origin.
