Abatement of Ocean-Wave Impact by Crevasses in an Ice Shelf

Authors :: Yuri V. Konovalov
Source :: Journal of Marine Science and Engineering, Volume 9, Issue 1, Journal of Marine Science and Engineering, Vol 9, Iss 46, p 46 (2021)
Publication Year :: 2021
Publisher :: Multidisciplinary Digital Publishing Institute, 2021.
Abstract: Forced ice-shelf oscillations modeling was undertaken employing a full 3D finite-difference model of an elastic ice shelf that was coupled to a treatment of under-shelf seawater flux. The seawater flux was described by the wave equation, which includes the pressure excitements in the shallow water layer under the ice shelf. Thus, ice-shelf flexure was produced by hydrostatic pressure oscillations in the below-shelf seawater. Numerical calculations were performed for an idealized rectangular crevasse-ridden ice-shelf geometry. The crevasses were modeled as rectangular notches into the ice shelf. In the numerical experiments, the ice-plate flexures were forced by harmonic-entering pressure oscillations having a range of periodicities 5&ndash 250 s. The dispersion spectra derived for a crevasse-ridden ice shelf revealed &ldquo band gaps&rdquo &mdash frequency ranges where no eigenmodes exist. The results further showed that the impact of ocean waves on the ice plate is abated from the point of view of a decrease in the spectral average amplitude in the vicinity of the spectrum where the &ldquo are observed. This impact depends on the depth of crevasse penetration to the ice.