Labrador Sea

Lore & Background

The Labrador Sea is an arm of the North Atlantic Ocean, bordered by the Labrador Peninsula to the southwest and Greenland to the northeast, with continental shelves along its southwestern, northwestern, and northeastern flanks. It connects northward to Baffin Bay via the Davis Strait. The sea formed between about 60 and 40 million years ago due to the separation of the North American and Greenland Plates, a process that included volcanic eruptions of picrites and basalts in the Davis Strait and Baffin Bay during the Paleocene. A sedimentary basin, now buried under the continental shelves, had developed earlier during the Cretaceous. The sea reaches depths of approximately 3,400 meters and a width of about 1,000 kilometers where it joins the Atlantic, shallowing to less than 700 meters toward Baffin Bay. Its bottom features the Northwest Atlantic Mid-Ocean Channel (NAMOC), one of the world’s largest turbidity current channel systems, extending thousands of kilometers along the seafloor. Water temperatures range from -1°C in winter to 5–6°C in summer, with salinity between 31 and 34.9 parts per thousand. In winter, two-thirds of the sea is covered in ice. The Labrador Sea is a major source of North Atlantic Deep Water, a cold, deep water mass that flows along the western edge of the North Atlantic. The sea’s anticlockwise circulation is driven by the East Greenland, West Greenland, Baffin Island, and Labrador currents, which transport icebergs and influence navigation. Historically, the southern coast hosted Dorset, Beothuk, and Inuit settlements between about 500 BC and 1300 AD, with Dorset tribes later replaced by Thule people.

Reader's Guide

The Labrador Sea is about 3,400 m deep and 1,000 km wide where it joins the Atlantic Ocean, becoming shallower to less than 700 m towards Baffin Bay. The Northwest Atlantic Mid-Ocean Channel (NAMOC) is a 100–200 m deep turbidity current channel system, about 2–5 km wide and 3,800 km long, running near the sea's center from the Hudson Strait into the Atlantic. Water temperature varies between −1 °C in winter and 5–6 °C in summer, with salinity at 31–34.9 parts per thousand. Two-thirds of the sea is covered in ice in winter. The sea provides a significant part of the North Atlantic Deep Water (NADW); the top layer, Labrador Sea Water (LSW), has low salinity (34.84–34.89 parts per thousand), low temperature (3.3–3.4 °C), and high oxygen content. The Labrador Current maintains water temperature at 0 °C and salinity between 30 and 34 parts per thousand. Shrimp fisheries began in 1978, and cod fishing was halted in 1992 due to depleted fish populations.

Did You Know?

• The Labrador Sea formed upon separation of the North American Plate and Greenland Plate that started about 60 million years ago and stopped about 40 million years ago.
• The Northwest Atlantic Mid-Ocean Channel (NAMOC) is one of the world's longest drainage systems of Pleistocene age, running 3,800 km along the sea bottom.
• Two-thirds of the Labrador Sea is covered in ice in winter.
• The Labrador Sea Water (LSW), part of the North Atlantic Deep Water, has a temperature of 3.3–3.4 °C and salinity of 34.84–34.89 parts per thousand.
• Cod fishing in the Labrador Sea was halted in 1992 due to depleted fish populations.