140801 - Seawater softening of suture zones inhibits fracture propagation in Antarctic ice shelves.pdf (6.45 MB)
Seawater softening of suture zones inhibits fracture propagation in Antarctic ice shelves
journal contribution
posted on 2023-05-20, 17:34 authored by Kulessa, b, Booth, AD, O'Leary, M, McGrath, D, King, EC, Luckman, AJ, Holland, PR, Jansen, D, Bevan, SL, Sarah ThompsonSarah Thompson, Hubbard, BSuture zones are abundant on Antarctic ice shelves and widely observed to impede fracture propagation, greatly enhancing ice-shelf stability. Using seismic and radar observations on the Larsen C Ice Shelf of the Antarctic Peninsula, we confirm that such zones are highly heterogeneous, consisting of multiple meteoric and marine ice bodies of diverse provenance fused together. Here we demonstrate that fracture detainment is predominantly controlled by enhanced seawater content in suture zones, rather than by enhanced temperature as previously thought. We show that interstitial seawater can reduce fracture-driving stress by orders of magnitude, promoting both viscous relaxation and the development of micro cracks, the incidence of which scales inversely with stress intensity. We show how simple analysis of viscous buckles in ice-penetrating radar data can quantify the seawater content of suture zones and their modification of the ice-shelf’s stress regime. By limiting fracture, enhancing stability and restraining continental ice discharge into the ocean, suture zones act as vital regulators of Antarctic mass balance.
History
Publication title
Nature CommunicationsVolume
10Article number
5491Number
5491Pagination
1-12ISSN
2041-1723Department/School
Institute for Marine and Antarctic StudiesPublisher
Nature Publishing GroupPlace of publication
United KingdomRights statement
Copyright 2019 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/Repository Status
- Open