Duration of the Occurrence of Mw ≥ 4.5 Aftershocks of the 2 April 2024 Mw 7.4 Hualin, Taiwan Earthquake

ABSTRACT Taiwan was shaken in the early morning of 2 April 2024 by an Mw 7.4 earthquake. Earthquakes of magnitude 7 and above are normally followed by damaging aftershocks. It is useful to have an estimate as to how long such aftershocks will continue. This knowledge helps in the recovery process. The duration of occurrence of the aftershocks of certain magnitudes can be estimated using Omori’s Law. Using the data of the aftershocks of the first 14 days after the Hualien earthquake, we estimated that the Mw ≥ 4.5 aftershocks shall continue for 80 days. Now, we are presenting analysis of recently available catalog up to 80 days to check and validate the prediction. Our analysis suggests that the rate of Mw ≥ 4.5 aftershocks in the region has gone down to the background seismicity rate after the estimated period of time.