.jpg)
A former channel beneath the Milne Ice Shelf, exposed after the ice broke apart. The channel carried freshwater from the epishelf lake to the Arctic Ocean.
Photo Credit: Cameron Fitzpatrick
Scientific Frontline: Extended "At a Glance" Summary: Epishelf Lakes and the Milne Fiord Loss
The Core Concept: An epishelf lake is a rare body of water where a layer of fresh water floats directly on top of denser, connected ocean salt water, trapped in place by an ice shelf acting as a dam.
Key Distinction/Mechanism: Unlike standard lakes, an epishelf lake features a unique dual ecosystem separated only by a thin density boundary, supporting freshwater microorganisms near the surface and marine species below, dependent entirely on the structural integrity of the surrounding ice shelf.
Origin/History: These systems require thousands of years to form. The Milne Fiord epishelf lake, located on northern Ellesmere Island in Nunavut, Canada, was monitored for over a decade before the Milne Ice Shelf collapsed in July 2020.
Major Frameworks/Components:
- Ice Shelf Dam: Thick, floating extensions of land ice that physically block fresh water from flowing into the open ocean.
- Density Stratification: The physical principle where less dense fresh water (often from glacial melt) remains floating above denser marine salt water without mixing.
- Rapid Salinization: The process following the collapse of the ice shelf barrier where the freshwater layer drains into the ocean and is quickly replaced by brackish or fully saline water.


.jpg)

.jpg)
.jpg)
.jpg)




.png)
.jpg)





