Combining physics-based and statistics-based approaches to model calving in Antarctica
Surface and basal crevasses are deep fractures in ice that are observed on the surface and the base of the Antarctic ice sheet/ice shelves, respectively. They are a direct pre- cursor of formation of rifts in ice shelves and a consequent calving or breaking off of icebergs. Modelling of calving is c...
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
The Australian National University
2019
|
| Subjects: | |
| Online Access: | https://dx.doi.org/10.25911/5c765954dc1a1 https://openresearch-repository.anu.edu.au/handle/1885/156513 |
| Summary: | Surface and basal crevasses are deep fractures in ice that are observed on the surface and the base of the Antarctic ice sheet/ice shelves, respectively. They are a direct pre- cursor of formation of rifts in ice shelves and a consequent calving or breaking off of icebergs. Modelling of calving is crucial for better estimation of the ice mass balance in Antarctica because ice shelves act like a supporting mechanism for the inland ice preventing it from accelerating into the ocean. While there have been a number of studies that attempted to parameterise calving, each of them has limitations that do not allow to apply them to all the Antarctic ice shelves on a large scale. A more comprehensive calving model needs to include not only parameterisation of calving at ice fronts, but also the history of fracturing of the ice that led to a calving event such as formation, advection and propagation of both surface and basal crevasses. Towards improving a calving parameterisation in ice sheet models we constructed a set of sub-models for predicting surface and basal fracturing, vertical and horizontal propagation as well as advection. Combining statistics-based and physics-based ap- proachers we developed a preliminary calving model that includes the full history of rifts and crevasses, from their initiation to the final break off at the ice front. |
|---|