Drake Passage

Here is the rewritten encyclopedia entry about the Drake Passage.

The Drake Passage, also known as the Sea of Hoces (Mar de Hoces), is the stretch of ocean separating Cape Horn, Chile—the southern tip of the South American mainland—from Antarctica’s South Shetland Islands. It links the southwestern Atlantic (Scotia Sea) to the southeastern Pacific. Its English name honors Sir Francis Drake, the 16th-century English explorer and privateer.

This passage is notorious as one of the most dangerous maritime routes. The Antarctic Circumpolar Current flows through it unimpeded by any landmass, generating waves over 40 feet high and earning it a reputation as the most powerful convergence of seas. Because it is the narrowest choke point around Antarctica, the Drake Passage heavily influences global oceanic circulation, climate patterns, and the mixing of ocean waters. Part of this water is designated the Southern Zone Sea.

**History** Spanish navigator Francisco de Hoces is thought to have discovered the passage in 1525 when a storm blew him south from the Strait of Magellan. He, his ship, and crew vanished, and their exact path remains unknown. Nevertheless, Spanish maps and sources call it the Mar de Hoces, while other Spanish-speaking countries use Pasaje de Drake (mainly in Argentina) or Paso Drake (mainly in Chile). The English name came from Sir Francis Drake during his circumnavigation. In 1578, after passing through the Strait of Magellan with the *Marigold*, *Elizabeth*, and his flagship *Golden Hind*, Drake entered the Pacific and was driven far south by a tempest. The *Marigold* was lost, the *Elizabeth* abandoned the fleet, and only the *Golden Hind* entered the passage, proving to the English that open water existed south of South America. Dutch navigator Willem Schouten became the first to sail around Cape Horn and through the passage in 1616. On December 25, 2019, a crew of six explorers made history by rowing across it for the first time, a feat documented in the 2020 film *The Impossible Row*.

**Geography** The passage formed when Antarctica separated from South America due to plate tectonics, though the timing is debated, with estimates ranging from 49 to 17 million years ago. The Shackleton fracture zone lies beneath its waters. This opening dramatically affected global oceans by enabling deep currents like the Antarctic Circumpolar Current (ACC). It may have triggered major shifts in global circulation and climate, as well as the rapid expansion of Antarctic ice sheets, because the encircling ocean currents cut Antarctica off from warmer regions. The 800-kilometer crossing between Cape Horn and Livingston Island is the shortest route from Antarctica to any other landmass. The boundary between the Atlantic and Pacific Oceans is sometimes drawn from Cape Horn to Snow Island (130 km north of mainland Antarctica), though the International Hydrographic Organization defines it as the meridian at 67° 16′ W, both lines lying within the passage. Unlike the narrow, treacherous Strait of Magellan and Beagle Channel, which offer little maneuvering room and unpredictable winds, the Drake Passage provides hundreds of miles of open water, making it the preferred route for most sailing ships. No significant land exists at these latitudes, allowing the Antarctic Circumpolar Current to flow eastward unimpeded, carrying a huge volume of water. The passage hosts whales, dolphins, and seabirds such as giant petrels, other petrels, albatrosses, and penguins.

**Importance in Physical Oceanography** The Drake Passage connects the Atlantic, Pacific, and Southern ocean basins via the Antarctic Circumpolar Current (ACC), the strongest oceanic current, with an estimated transport of 100–150 Sverdrups (million m³/s). This flow is the only large-scale exchange between global oceans, and the passage is the narrowest point on its route around Antarctica. Extensive research focuses on how the passage’s shape—its bathymetry and width—affects global climate. Major features of modern ocean temperature and salinity, including the thermal asymmetry between hemispheres, the saltiness of deep water formed in the Northern Hemisphere, and the existence of a transequatorial conveyor circulation, developed after the passage opened. The Roaring Forties and Furious Fifties winds drive the Antarctic Circumpolar Current, and the passage plays a key role in this mechanism, ensuring the current interacts with other ocean basins rather than closing in on itself.