Seismic Station RA086 Statistical Analysis of Earthquake Data Using Shake Net and Grapher on the Global Seismic Activity: Analyzing Earthquake Patterns, Clustering, and Implications for Hazard Assessment

Abstract

The paper examines earthquake activity in 2023 using data from the active seismic station RA086 in the city of São Tomé. Five thousand and twenty-four (5,224) events of earthquakes were observed and processed with ShakeNet software and Grapher. On May 20, 2023, a strong earthquake of magnitude 7.6 was reported in the Pacific Ocean, off the coast of the Tanimbar Islands in Indonesia, at a depth of 105 km, and was followed by frequent earthquakes. The data reveal the distribution of earthquakes around the world, which is mainly concentrated in tectonic hotspots like the Pacific Ring of Fire, with magnitudes ranging from very large (7.6) to moderate. The earthquakes varied greatly in depth, ranging from shallow crustal earthquakes to deep-seated, long-focus earthquakes in the subduction zone, with depths over 500km. The analysis also shows frequent coalescence of mainshocks and aftershocks, particularly in subduction trenches, indicating continuous tectonic processes. Another aspect highlighted by the data is that both shallow and deep seismic events should be monitored, as energy released at different depths can affect surface shaking and the potential for disaster.