What to Expect When Crossing the Drake Passage
Sitting between the southern tip of South America and the north-reaching arm of Antarctica is the body of water known as the Drake Passage. Considered the gateway to the Antarctic, Drake Passage (about 1,000 km wide) is considered by some as a rite of passage for those wishing to consider themselves true explorers of our southern-most continent.
The wild Drake Passage
In the Drake Passage cold and warm sea water layers mix to regulate the Earth’s climate and ocean currents. This mixing happens in a tight 600 mile-wide gap and so not only does the current speed up but it creates powerful eddies. Combined with strong winds and at times violent storms, it makes the Drake Passage one of the roughest patches of sea on Earth.
It is through the Drake Passage that the Antarctic Circumpolar Current (ACC) flows through, from west to east encircling Antarctica. The ACC stretches over 20,000 kilometres, forming the world’s largest ocean current. The average flow is estimated to be around 135 million cubic metres of water per second. The ACC allows water transfer between the oceans and is driven by the strong winds of the Polar Front, which extend between the latitudes of 40°S and 60°S where the average wind speed is between 15 and 20 knots.
The Currents, the Weather, and the Waves
It takes the average cruise ship about 48 hours to get through the Passage. Whether that’s a gentle voyage or a wilder ride depends on three main factors.
The currents around Antarctica hustle around the continent in a clockwise direction, unimpeded by land masses unlike the currents of the more northerly oceans. This flow, known as the Antarctic Circumpolar Current, moves a massive amount of water (between 95 and 150 million cubic metres per second - roughly 600 times more than the Amazon River) through the narrowing passage.
Once free of the Drake Passage the currents fan out, most of it continuing east or northeast, with a smaller portion heading more directly north into the South Atlantic. This latter branch is known as the Falkland Current.
Passengers heading across the passage can expect temperatures ranging from about 5°C in the north to -3°C in the south. Weather-wise, the real impact in the passage comes from the storms. Whether you get a storm during your cruise is a bit of a gamble – there is no real storm-less season. Some days the water will be surprisingly calm, almost glass-like, and others will present your cruise to Antarctica with rolling swells.
This combination of currents, whipping winds, and low pressure fronts flying circles around the continent can add up to a wild ride that can, at its worst, reach a 10 on the Beaufort Scale (a 12 on the scale is a hurricane). All of this means that if you don’t have the good fortune of hitting the calm periods (the calmest being known as turning the waters into the “Drake Lake”) you’re going to be in for some rocking and rolling. If you’re prone to seasickness then it’s definitely a good idea to see your doctor before you ship out and get a little medical help to counter motion sickness. And even if you’re the type who laughs at the twistiest of roller-coasters there’s a good chance that the Drake Passage’s rougher weather is going to test that cast-iron stomach of yours, so you might be well advised to take a trip to the doctor along with your queasier friends.
Tracking the current through Drake Passage
To understand more about this mixing of ocean water, scientists from the University of Exeter as well as University of East Anglia, University of Southampton, the Woods Hole Oceanographic Institution, the British Antarctic Survey ad the Scottish Association of Marine Science, measured the mixing by releasing tiny quantities of an inert chemical tracer in the Southeast Pacific and tracked the tracer for several years as it went through the Drake Passage to observe how quickly the ocean mixed. The research found that as the water passed over the mountainous ocean floor in the narrow continental gap that forms the Drake Passage it began to mix dramatically.
Drake Passage wildlife
The Drake Passage is densely populated by plankton, the start of a richly varied food chain.
The passage and its surrounding seas are home to Antarctic cod, squid, seals, penguins, multiple species of sea birds, and a variety of whales.