Association between earthquake and equatorial waves in Outgoing Longwave Radiation over South East Asia

Abstract

In the present study, efforts has been made to correlate the equatorial planetary waves in Outgoing Longwave Radiation (OLR) and to seismic activities in South East Asian region. The OLR data has been obtained from NOAA Climate Prediction Centre web site.  The earthquake information has been obtained from USGS earthquake information centre. This paper present observations for the two earthquakes, i.e., 26 January 2001, Bhuj, India and 26 December 2004, Sumatra, Indonesia. The normal days OLR has been compared to the OLR recorded during the seismic events. It has been observed that there is significant enhancement in OLR, few days before the earthquake event. The Morlet 6.6 wavelet analysis shows the presence of planetary waves in equatorial OLR for period about 6 days, during and about 80 days before the earthquake. The OLR data were analysed in such a way that the other possible effects are minimized. The anomalous increase and presence of planetary waves before 80 days of seismic event shows great potential in providing early warning of a disastrous earthquake. It should be noted that planetary waves is generated only in the equatorial region irrespective of strong/severe earthquake location.