Ion density and temperature variations at altitude of 500 km during moderate seismic activity

Abstract

Ionospheric ions (O + and H + ) and temperature (Ti) as precursory parameters to seismic activity have been analysed from year 1995 till 1998, using SROSS-C2 (average altitude range of ~ 500 km) satellite measurements for moderate magnitude earthquakes. The details of seismic events during this period are downloaded from United State Geological Survey (USGS) and National Earthquake Information Centre (NEIC) website. 13 seismic events of moderate magnitude (M = 4 -5.5) from 1995-1998, using SROSS-C2 satellite measurements have been analyzed. During seismic affected period, considerable decrease in the density of heavier ion -O + and increase in the ion temperature (Ti) is observed during all the selected events. Lighter ion -H + doesn't show any significant change. Electric field and electromagnetic emissions generated due to seismogenic activity could be the plausible initializing agents responsible for change in ion concentration and temperature values during these events.