Evaluation of global seismicity along Northern and Southern hemispheres

Abstract. An earthquake has been identified as one of the major natural disasters that cause loss of lives and property. To mitigate this disaster, knowledge of global seismicity is essential. This research is aimed at evaluating the Gutenberg Richter b-value parameter and focal depth distribution of earthquake parameters to identify the prominent earthquake-prone zones in the Northern and Southern hemispheres. The study area covers 20° to the Northern and Southern hemispheres, with the equator in the middle. The data were obtained from the earthquake catalogue of the Advanced National Seismic System (ANSS) hosted by the Northern California Earthquake Data Centre USA from 1963–2018. Fifty-four-year earthquake data of M ≥ 6.0 were processed and analyzed using Gutenberg-Richter (GR). The b-value parameters obtained from the GR model were plotted against the hemispheres using bar chart graphs to determine the tectonic stress level of the study region. The earthquake energy released was evaluated along the Northern and Southern hemispheres for a proper understanding of seismic events in the study region. It was observed that the rate of earthquake occurrence at the Southern hemisphere is higher than the Northern hemisphere. The b-values obtained in all the zones vary from 0.82–1.16. At the same time, the maximum earthquake energy of 4.6 × 1025 J was estimated. Low b-values indicate high tectonic stress within the plates. The large tectonic stress accumulation around the equator suggests that unstable lithospheres characterize this zone.