title: Shock wave propagation along constant sloped ocean bottoms.
abstract: The nonlinear progressive wave equation (NPE) is a time-domain model used to calculate long-range shock propagation using a wave-following computational domain. Current models are capable of treating smoothly spatially varying medium properties, and fluid-fluid interfaces that align horizontally with a computational grid that can be handled by enforcing appropriate interface conditions. However, sloping interfaces that do not align with a horizontal grid present a computational challenge as application of interface conditions to vertical contacts is non-trivial. In this work, range-dependent environments, characterized by sloping bathymetry, are treated using a rotated coordinate system approach where the irregular interface is aligned with the coordinate axes. The coordinate rotation does not change the governing equation due to the narrow-angle assumption adopted in its derivation, but care is taken with applying initial, interface, and boundary conditions. Additionally, sound pressure level influences on nonlinear steepening for range-independent and range-dependent domains are used to quantify the pressures for which linear acoustic models suffice. A study is also performed to investigate the effects of thin sediment layers on the propagation of blast waves generated by explosives buried beneath mud line.
authors.affiliation: Department of Applied Mathematics and Statistics, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Maestas
authors.affiliation: CiviCore, 1580 Lincoln Street, Denver, Colorado 80203.
authors.forename: Larissa F
authors.initials: LF
authors.lastname: Taylor
authors.affiliation: Department of Applied Mathematics and Statistics, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401.
authors.forename: Jon M
authors.initials: JM
authors.lastname: Collis
mesh_terms: D000162:Acoustics; D003198:Computer Simulation; D019015:Geologic Sediments; D019220:High-Energy Shock Waves; D016014:Linear Models; D017711:Nonlinear Dynamics; D009792:Oceans and Seas; D013018:Sound Spectrography