NSF PLR 1847173 – CAREER: Fracture Mechanics of Antarctic Ice Shelves and Glaciers – Representing Iceberg Calving in Ice Sheet Models and Developing Cyberlearning Tools for Outreach

Overview

Iceberg calving is a complex natural fracture process and a dominant cause of mass loss from the floating ice shelves on the margins of the Antarctic ice sheet. There is concern that rapid changes at these ice shelves can destabilize parts of the ice sheet and accelerate their contribution to sea-level rise. The goal of this project is to understand and simulate the fracture mechanics of calving and to develop physically-consistent calving schemes for ice-sheet models. This would enable more reliable estimation of Antarctic mass loss by reducing the uncertainty in projections. The two research aims are to:

(1) investigate crevasse propagation in viscous glacier ice using conduct full-Stokes fracture mechanics models; and

(2) develop fracture-physics-based calving schemes for depth-integrated, higher-order Stokes flow approximations in ice sheet models.

This project aims to provide fundamental understanding of iceberg calving by advancing the frontiers in computational fracture mechanics and nonlinear continuum mechanics and translating it to glaciology. The project investigates crevasse propagation using poro-damage mechanics models for hydrofracture that are consistent with nonlinear viscous ice rheology, along with the thermodynamics of refreezing in narrow crevasses at meter length scales. It will develop a fracture-physics based scheme to better represent calving in ice-sheet models using a multiscale method. The effort will also address research questions related to calving behavior of floating ice shelves and glaciers, with the goal of enabling more reliable prediction of calving fronts in whole-Antarctic ice-sheet simulations over decadal-to-millennial time scales.

The research plan is integrated with an education and outreach plan that aims to (1) enhance computational modeling skills of engineering and Earth science students through a cross-college course and a high-performance computing workshop and (2) increase participation and diversity in engineering and sciences by providing interdisciplinary research opportunities to undergraduates and by deploying new cyberlearning tools to engage local K-12 students in the Metro Nashville Public Schools in computational science and engineering, and glaciology.

Publications

  1. S. Jimenez, R. Duddu and J. N. Bassis, “A nonlocal continuum damage mechanics approach for hydrofracturing of surface crevasses in grounded glaciers.” Journal of Glaciology, to be submitted.
  2. V. Devendiran and R. Duddu, “A phase field model for simulating mixed-mode fracture of brittle materials under uniaxial and biaxial compression.” Computational Mechanics, to be submitted.

Presentations

  1. V. K. Devendiran and R. Duddu. “An appropriate crack driving force function for the phase field approach to model mixed-mode brittle fracture.” ASCE EMI 2019 Conference, Pasadena, CA, June 18 – June 21, 2019.

Students

vignesh

Vignesh Kumar Devendiran

Ph. D. student, Expected graduation: June 2021

Research project: Modeling hydromechanical fracture and shear failure in ice shelves and glaciers using continuum damage mechanics