Earth Planets Space, Vol. 58 (No. 2), pp. 167-172, 2006
Ashish DasGupta 1,2, Aditi Das1, Debrup Hui2, Kalyan Kumar Bandyopadhyay3, and M. R. Sivaraman3
1Institute of RadioPhysics and Electronics, University of Calcutta, Kolkata, India-700009
2S. K. Mitra Center for Research in Space Environment, University of Calcutta, Kolkata, India-700009
3Space Application Center, Ahmedabad, India-380015
(Received June 30, 2005; Revised December 5, 2005; Accepted December 12, 2005; Online published February 17, 2006)
Using the Total Electron Content (TEC) data recorded by the GPS receiver network, installed under the GPS and Geo Augmented Navigation (GAGAN) program, ionospheric electron content on the day of the great Sumatra-Andaman earthquake of December 26, 2004 was examined. A significant perturbation of 1.5 to 2 TEC units over a smooth variation of TEC in the morning hours was observed within 45 minutes of the quake at stations situated near the east coast of the Indian subcontinent. The disturbance was found to propagate northwestward with its origin situated about 2° northeast of the quake epicenter. Possible coupling mechanism of the crustal movement and the ionosphere are discussed.
Key words: Earthquake, tsunami, ionospheric response, atmospheric gravity wave, Total Electron Content, seismoelectric effect.