The source of compressional Pc3 magnetic pulsations has been considered to be the plasma process in the solar wind or in the magnetosphere. However, the excitement of some of the Pc3s seems to be related to strong inland earthquakes that occur on the dayside. The Lamb waves generated by the Tonga undersea volcanic eruption in January 2022 are also believed to have excited large amplitude and short period compressional Pc3 geomagnetic pulsations in the dayside plasmasphere (Iyemori et al., 2025). A common epoch analysis shows an increase in power spectral density (PSD) in the Pc3 frequency band 10-30 minutes after the origin time of large inland earthquakes (M>6.5) during the daytime (10-14 LT). These observations suggest that the acoustic waves emitted by the ground motion at the earthquakes are the source of the Pc3s. In this presentation, we confirm the existence of the Pc3s excited by the earthquakes and discuss their generation mechanism.