Characteristics of T-waves Excited by the 3 April 2024 Mw 7.3 Hualien, Taiwan, China Earthquake Sequence and Their Relationship with Source Parameters

Oceanic T-waves are sensitive to weak seismic and acoustic signals and hold significant advantages for constraining earthquake and tsunami characteristics, monitoring ocean temperature changes, and other marine environmental observations. However, the quantitative relationship between T-wave features and seismic source parameters remains unclear. This study analyzes the characteristics (e.g., arrival time, duration, energy) of T-waves excited by the 3 April 2024 Mw 7.3 Hualien, Taiwan mainshock and its aftershock sequence, using records from Pacific CTBTO hydrophone arrays and island-based seismic stations. The results indicate that the Hualien earthquake sequence generated prominent T-wave signals, whose excitation strength correlates positively with earthquake magnitude. Furthermore, systematic differences in energy were observed between T-waves excited by near-shore earthquakes and those from typical submarine earthquakes, suggesting that source location and mechanism play a critical role in T-wave generation efficiency. The analysis confirms that T-waves, even after long-distance propagation, retain high-frequency information from the source process. Their waveform characteristics can provide independent constraints on source parameters, offering valuable insights for utilizing T-waves in source parameter inversion.