Hydro-Acoustic Wave Generation during the Tohoku-Oki 2011 Earthquake

Role of Compressibility on Tsunami Propagation

“…Governing equations and the resulting eigenvalues, eigenfunctions and dispersion relation for monochromatic wave components are presented in section 2. In section 3, we derive a modified MSEWC which extends the original formulation of Sammarco et al () to account for the compressibility of the static ocean. Verification of the mild‐slope equation model is carried out for constant and varying geometries against a fully 3‐D model in section 4. In section 5, following Tappin et al () and Abdolali et al (), the generation mechanism of the 2011 Tohoku‐oki is modeled as a combination of the space and time varying coseismic seafloor deformation caused by the earthquake followed by a submarine mass failure (SMF) to justify the mismatch between arrival time at far field gauges, calculated from incompressible models. Conclusions are given in section 6.…”

Lattice Boltzmann approach for hydro-acoustic waves generated by tsunamigenic sea bottom displacement

“…Researchers have studied two frequency ranges for acoustic waves associated with tsunamigenesis: (1) low frequency HAW with characteristic frequencies ∼ 0.1Hz, and (2) T-waves, in frequencies in the range between 2 and 100Hz. Low frequency HAW generated by seabed motion were measured during the Tokachi-Oki 2003 and Tohoku-Oki 2011 tsunami events by the Japan Agency for Marine-earth Sciences and TEChnology observatory and later have been used to estimate amplitude, duration, and velocity of bottom displacements, and as benchmarks for 3D and 2D numerical models (Nosov and Kolesov, 2007;Bolshakova et al, 2011;Abdolali et al, 2015d). During the 2012 Haida Gwaii event in Canada, bottom pressure signals were used to reveal the frequency ranges associated with gravity waves and HAW (Abdolali et al, 2015a).…”

“…As these approaches are computationally demanding, resort has been made to vertically integrated formulations of the same set of equations, as in Sammarco et al (2013) and Abdolali et al (2015c). These models proved to be not only accurate enough to capture the main far-field features of HAW for idealized cases, but also efficient enough to be employed to reproduce real tsunamis (Abdolali et al, 2014(Abdolali et al, , 2015aCecioni et al, 2015;Abdolali et al, 2015d). The main drawback of these depth-integrated models lies in leaving out both the horizontal component of bed deformation and vertical variations of the propagation medium.…”