Magnitude–Frequency Analysis of Earthquakes in Bangladesh Using the Gutenberg–Richter Law

This study examines the seismic activity in the Bengal Basin from 2000 to 2026, emphasizing the tectonic risks faced by the Dhaka megacity. It is noticed that the focal depths exhibit a bimodal distribution between 10–15 kilometers and 60–100 kilometers. A three-dimensional spatial map clearly shows a Benioff zone that dips to the east. A correlation coefficient of -0.04 shows that the depth of an earthquake doesn't change its size. This means that both shallow crustal and deep subduction faults are equally dangerous. We used the Gutenberg–Richter Law to find that the seismic activity rate (a-value) was 5.912 and the magnitude-frequency slope (b-value) was 0.89039. A b-value under 1.0 means that tectonic stress is building up quickly, which makes severe disasters more likely to happen. The average magnitude trend has stayed the same, but the number of tremors has gone up from 2020 to 2026. This means that the seismic gap is getting smaller, therefore regional disaster preparedness needs to be improved right away.