ИСТИНА

The effect of the fault rupture kinematics in the earthquake source on tsunami generation is investigated. According to previous theoretical studies, the kinematics of the fault rupture affects both tsunami amplitude and total tsunami energy (Nosov 1998; Todorovska & Trifunac 2001). This study has two objectives: (1) to evaluate the effect of the fault rupture kinematics on the sixteen 1992 ­­­– 2021 tsunamis in terms of total tsunami energy; and (2) to investigate the Illapel 2015 event more thoroughly in terms of tsunami amplitude and time series of tsunami height.For each of the sixteen events kinematic tsunami source (bottom motion during the earthquake) and static tsunami source (permanent bottom deformation) were calculated based on the Finite Fault Models provided by the U.S. Geological Survey. For both types of sources, numerical simulations of tsunamis were carried out in the framework of the linear long-wave theory. It is found that in eleven out of sixteen events, the total energy of tsunami excited by the kinematic source is greater than that excited by the static source. The maximum energy amplification (9.1%) is observed at the minimum ratio of average rupture velocity to long-wave velocity, as was predicted by theory.Illapel 2015 event is investigated in detail using dispersive tsunami models JAGURS and CPTM. The JAGURS model is based on two-dimensional nonlinear Boussinesq dispersive equations in spherical coordinates (Baba et al. 2015), while the CPTM model is based on three-dimensional compressible fluid potential theory equations (Nosov & Kolesov 2019). It is found that the kinematic source leads to spatial redistribution of tsunami amplitudes and a noticeable amplification of the high-frequency component in the time series of tsunami height. At some points along the Chilean coast, the difference between the kinematic and static calculations is more than 2 m.