Rupesh M. Das

Ionospheric perturbations over Delhi caused by the 26 December 2004 Sumatra earthquake

The death and destruction caused by the Sumatra earthquake on 26 December 2004 have once again jolted seismologists to find a reliable early warning system of an impending major earthquake. The F‐region ionospheric parameters probed remotely by a digital ionosonde over Delhi (28.6° N, 77.2° E) have shown precursory signatures of 26 December 2004 Sumatra earthquake. Results indicate severe perturbations in foF2 and hmF2 several hours before the deadly earthquake. The wavelike perturbations in foF2 continued for several days after the event. It is important to note that this earthquake struck at a time when there were no solar or geomagnetic disturbances to cause any anomalous ionospheric changes.