Swell induced vibrations of a thickening ice shelf over a shoaling seabed

TL;DR

This paper presents a new method to model and analyze how ice shelf vibrations are affected by ocean waves, ice thickness, seabed changes, and grounding conditions, providing insights into their dynamic response.

Contribution

It introduces a combined decomposition, finite element, and non-local operator approach to model ice shelf vibrations with variable thickness and seabed, including irregular wave responses.

Findings

Ice shelves experience significant vibrations due to swell.

Thickening of ice shelves influences vibration response.

Seabed shoaling affects the prediction of ice shelf dynamics.

Abstract

A solution method is developed for a model of ice shelf vibrations in response to ocean waves, in which the ice shelf thickness and seabed beneath the ice shelf vary over distance, and the ice shelf/sub--ice--shelf cavity are connected to the open ocean. The method combines a decomposition of the ice shelf motion into free modes of vibration, a finite element method for the cavity water motion, and a non-local operator to connect to the open ocean. An investigation is conducted into the effects of ice shelf thickening, seabed shoaling and the grounding-line conditions on ice shelf vibrations, induced by regular incident waves in the swell regime. Further, results are given for ice shelf vibrations in response to irregular incident waves, and ocean-to-ice-shelf transfer functions are derived. The findings add to evidence that ice shelves experience appreciable vibrations in response to swell, and that ice shelf thickening and seabed shoaling can have a considerable influence on predictions of how ice shelves respond to ocean waves.