Bransfield Strait is a body of water about 60 mile wide extending for 200 mile in a general northeast-southwest direction between the South Shetland Islands

South Shetland Islands

The South Shetland Islands are a group of Antarctic islands, lying about north of the Antarctic Peninsula, with a total area of . By the Antarctic Treaty of 1959, the Islands' sovereignty is neither recognized nor disputed by the signatories and they are free for use by any signatory for...

 and Antarctic Peninsula

Antarctic Peninsula

The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....

. It was named in about 1825 by James Weddell

James Weddell

James Weddell was a British sailor, navigator and seal hunter who in the early Spring of 1823 sailed to latitude of 74°15' S and into a region of the Southern Ocean that later became known as the Weddell Sea.-Early life:He entered the merchant service very...

, Master, Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

, for Edward Bransfield

Edward Bransfield

Edward Bransfield was a master of the British Royal Navy and considered the discoverer of the continent of Antarctica.-Early life:...

, Master, RN, who charted the South Shetland Islands in 1820. It is called Mar de la Flota by Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

.

The undersea trough

Trough (geology)

In geology, a trough generally refers to a linear structural depression that extends laterally over a distance, while being less steep than a trench.A trough can be a narrow basin or a geologic rift....

 through the strait is known as Bransfield Trough (61°30′S 54°0′W). The basin is about 400 km length and 2 km depth, between the South Shetland Island Arc and the Antarctic Peninsula. It was formed by rifting behind the islands, which began about 4 million years ago. This ongoing rifting has caused recent earthquakes and volcanism along the Bransfield Strait. The Strait hosts a chain of submerged seamounts of volcanic origin, including in particular the presently inactive Orca Seamount

Orca Seamount

Orca Seamount is a seamount near King George Island and Cape Sherriff Field Station in Antarctica, in the Bransfield Strait...

.

On the 23rd November 2007, the MS Explorer

MS Explorer

The MS Explorer was a Liberian-registered cruise ship designed for Arctic and Antarctic service, originally commissioned and operated by the Swedish explorer Lars-Eric Lindblad...

 struck an iceberg

Iceberg

An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...

and sank in the Bransfield Strait. All 154 passengers were rescued. No injuries were reported.