Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse.
Sci Adv
; 9(43): eadi7638, 2023 Oct 27.
Article
in En
| MEDLINE
| ID: mdl-37889975
ABSTRACT
Ocean conditions near the grounding zones of Antarctica's ice shelves play a key role in controlling the outflow and mass balance of the ice sheet. However, ocean observations in these regions are largely absent. Here, we present a detailed spatial survey collected with an underwater vehicle in a basal crevasse located in the ocean cavity at the Ross Ice Shelf grounding zone. The observations depict fine-scale variability in ocean forcing that drives asymmetric melting along the lower crevasse sidewalls and freezing in the upper reaches of the crevasse. Freshwater release from melting at depth and salt rejection from freezing above drives an overturning circulation. This vertical circulation pattern overlays a dominant throughflow jet, which funnels water parallel to the coastline, orthogonal to the direction of tidal currents. Importantly, these data reveal that basal crevasses influence ocean circulation and mixing at ice shelf grounding zones to an extent previously unknown.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Sci Adv
Year:
2023
Document type:
Article
Affiliation country:
United States