50 Fun Facts About Oceanography

Which cargo, washed off a container ship in a 1992 storm, helped oceanographers trace surface currents for years?

Rubber ducks were among 28,800 bath toys lost overboard, and they kept washing up on distant beaches. Oceanographer Curtis Ebbesmeyer used beachcombers' finds to test a model of ocean currents.

Which seabed mineral lumps did the CIA pretend to be mining in 1974 while secretly raising a sunken Soviet submarine?

Manganese nodules were the cover story for Project Azorian, with Howard Hughes lending his name to the fake mining venture. The ship Hughes Glomar Explorer recovered a portion of the submarine K-129.

Which sea in the North Atlantic is the only one on Earth bounded by ocean currents instead of land?

The Sargasso Sea is hemmed in by four currents and named after the brown Sargassum seaweed that floats on it in mats. European and American eels migrate there to spawn.

Which British warship's voyage of 1872 to 1876 is credited with laying the foundations of modern oceanography?

HMS Challenger sailed almost 69,000 nautical miles with laboratories on board, and its scientists found about 4,700 new species. A NASA space shuttle was later named after the ship.

Which warm Atlantic current did Benjamin Franklin chart in the 1700s to help mail ships cross faster from England?

The Gulf Stream was costing British mail packets weeks on the westbound crossing. Franklin had a sea captain named Folger sketch its path on a chart, with notes on how to steer clear of it.

Which naturalist proposed in 1842 that coral atolls form as reefs grow upward around slowly sinking volcanic islands?

Charles Darwin based the idea on reefs he had studied during the five-year voyage of HMS Beagle. He published it 17 years before On the Origin of Species.

Which crescent-shaped feature of the western Pacific seabed holds the deepest known point in any ocean?

The Mariana Trench drops nearly 11 kilometres. If Mount Everest stood on its floor, the summit would still lie more than 2 kilometres under water.

Which French naval officer co-invented the Aqua-Lung during World War II, freeing divers from surface air hoses?

Jacques Cousteau built it with engineer Émile Gagnan in occupied France over the winter of 1942 to 1943. He went on to use it to film beneath the waves.

Which microscopic drifting organisms produce about half of Earth's oxygen while making up only 1% of plant biomass?

Phytoplankton live in the sunlit surface layer, where they take in carbon dioxide and release oxygen. They also carry out about half of all the photosynthesis on Earth.

Which climate pattern starts when trade winds weaken and warm water surges east across the tropical Pacific?

El Niño was named by Peruvian sailors after the Christ Child, because the warm water tended to show up around Christmas. Its cooler opposite phase is called La Niña.

Which result of Earth's rotation bends ocean currents right in the Northern Hemisphere and left in the Southern?

The Coriolis effect takes its name from French scientist Gaspard-Gustave de Coriolis, who set out the mathematics in an 1835 paper. His subject was water wheels, not the sea.

Which slow, density-driven flow of the deep ocean is nicknamed the global conveyor belt by climate scientists?

Thermohaline circulation is named from thermo for heat and haline for salt, the two things that set the density of seawater. Climate scientist Wallace Broecker coined the conveyor belt nickname.

Which name is given to the extra-large tidal ranges that occur at every new and full moon, in any season?

Spring tides are not named after the season. The word comes from an older sense of spring meaning to jump, burst forth or rise, as water does in a natural spring.

Which Canadian bay has the highest tidal range in the world, reaching about 16 metres thanks to its funnel shape?

The Bay of Fundy rises and falls so far because the water resonates in its long, funnel-shaped basin. The typical range in the open ocean is only about one metre.

Which waves, usually set off by undersea earthquakes, cross deep ocean at jetliner speed yet pass ships unnoticed?

Tsunamis travel at well over 800 km/h in deep water but stand only about a metre high there. Near the coast they slow below 80 km/h and the shallowing seabed squeezes them upward.

Which traditional unit of water depth equals six feet, originally the span of a man's outstretched arms?

The fathom gets its name from an Old English word meaning embracing arms. Water past the 100-fathom line, too deep for a hand sounding line, was said to be off soundings.

Which American oceanographer led the 1985 expedition that found the wreck of the Titanic on the Atlantic seabed?

Robert Ballard was really at sea for the US Navy, which wanted secret surveys of two sunken nuclear submarines, Thresher and Scorpion. He was free to hunt for the liner with whatever time remained.

Which marine biologist wrote the 1951 bestseller The Sea Around Us, years before her famous warning about pesticides?

Rachel Carson won the 1952 National Book Award for Nonfiction with her history of the oceans. It stayed on the New York Times Best Seller List for 86 weeks.

Which discarded items make up nearly half the mass of the Great Pacific Garbage Patch, according to a 2018 study?

Fishing nets, lost or dumped at sea, dominate the debris by weight. Sailor Charles Moore drew the world's attention to the floating rubbish after crossing it on his way home from a 1997 yacht race.

Roughly what share of seawater's weight is dissolved salts, which come mainly from rocks on land and seabed openings?

About 3.5% is the ocean average, which oceanographers usually write as a salinity of 35 parts per thousand. Rain slowly erodes rocks, and rivers carry the freed ions down to the sea.

Which compound forms as seawater soaks up the main greenhouse gas from human emissions, lowering ocean pH?

Carbonic acid forms when carbon dioxide reacts with water, and the sea takes up roughly a quarter of what people emit. Corals and mollusks then find it harder to build shells and skeletons.

Which ocean layer, dividing the warm mixed surface water from the cold deep, can hide submarines by reflecting sonar?

The thermocline is where temperature falls fastest with depth, and the speed of sound falls with it. That bends or bounces sonar pings, so a submarine below the layer is harder to detect.

Which term names a vast rotating system of wind-driven surface currents, five of which dominate the subtropics?

A gyre turns clockwise north of the equator and counterclockwise south of it in the subtropics. Floating plastic gathers inside these loops, which is how the ocean's rubbish patches form.

Which process off Peru and California lets just 5% of the ocean yield about a quarter of the world's fish catch?

Upwelling is the wind-driven rise of cold, dense water from the deep to replace surface water pushed offshore. The nutrients it carries fertilise the algae that feed huge shoals of fish.

Which gently sloping, shallow seabed bordering most coastlines was largely dry land during the ice ages?

The continental shelf ends at a drop-off that lies about 140 metres down almost everywhere. That uniform depth is thought to mark where the shoreline stood when ice sheets locked up the water.

Which process, proposed by Harry Hess and Robert Dietz in the 1960s, forms new ocean crust at mid-ocean ridges?

Seafloor spreading grew out of Hess's wartime service. As captain of a US Navy transport he kept the ship's echo sounder running across the Pacific and charted the seabed as he went.

Which American geologist mapped the Atlantic floor in the 1950s and found the rift valley along its central ridge?

Marie Tharp drew her maps on land from depth soundings that Bruce Heezen gathered aboard ship. Women were barred from working on research vessels for the first 18 years of their partnership.

Near which Pacific archipelago did scientists diving in Alvin find the first hydrothermal vents in 1977?

The Galápagos Islands lie beside a rift where geologists expected to find warm water. They were astounded to find the vents teeming with life, including clams and giant tube worms.

Which process lets bacteria at deep-sea hydrothermal vents make food from hydrogen sulfide without any sunlight?

Chemosynthesis feeds whole communities in the dark. Giant tube worms house the bacteria inside their bodies and live on the sugars the microbes make.

Which bathyscaphe carried Jacques Piccard and Don Walsh to the deepest known point in the ocean in 1960?

Trieste took 4 hours 47 minutes to sink to the bottom, and an outer window pane cracked on the way down. The two men stayed just twenty minutes before starting back up.

Which effect, first explained in 1902, makes each deeper layer of wind-driven water flow at a wider angle to the wind?

The Ekman spiral is named after Swedish oceanographer Vagn Walfrid Ekman. He worked out why Arctic sea ice had been seen drifting 20 to 40 degrees to the right of the wind.

Which term do oceanographers use for the distance of open water a wind blows across, which helps set wave size?

Fetch, wind speed and the time the wind keeps blowing together decide how large the waves grow. The same gale raises far smaller waves on a lake than on an open ocean.

Which ocean hazard, once considered mythical, was first detected by a measuring instrument in the North Sea in 1995?

A rogue wave 25.6 metres high struck the Draupner gas platform on New Year's Day 1995. The rig had been designed for a once-in-10,000-years wave of only 20 metres.

Which 800-kilometre-wide stretch of water between Cape Horn and Antarctica funnels the world's largest ocean current?

The Drake Passage squeezes the Antarctic Circumpolar Current, which flows from west to east right around the frozen continent. It is also the shortest crossing from Antarctica to any other landmass.

Which cold flow up the coasts of Chile and Peru forms the most productive eastern boundary system in the oceans?

The Humboldt Current is named after German naturalist Alexander von Humboldt, who reported measurements of it in 1846. José de Acosta had discovered it about 250 years earlier.

Which US Navy officer, nicknamed Pathfinder of the Seas, wrote the first comprehensive oceanography book in 1855?

Matthew Fontaine Maury turned to studying winds and currents after a leg injury left him unfit for sea duty. He built his charts from thousands of old ships' logs.

Which Norwegian explorer let his ship Fram drift in Arctic pack ice in the 1890s and later won the Nobel Peace Prize?

Fridtjof Nansen also designed a bottle for sampling deep water that stayed in use into the 21st century. His 1922 peace prize honoured his work for people displaced by the First World War.

Which body of water dried out almost completely nearly six million years ago, until the Atlantic flooded back in?

The Mediterranean Sea was cut off when the Strait of Gibraltar closed, and the dry climate emptied the basin within about a thousand years. Its refilling is known as the Zanclean flood.

Which single-celled algae, encased in ornate glass-like shells of silica, make at least a fifth of Earth's oxygen?

Diatoms leave their shells behind in deposits called diatomaceous earth. The crumbly rock is used for filtering water, as a mild abrasive, in cat litter and to stabilise dynamite.

Which animals' sunken carcasses become deep-sea oases, feeding bone-eating worms and other specialists for decades?

Whales that sink to the deep seabed create what scientists call a whale fall, first observed in the late 1970s. Osedax worms bore into the bones to reach the nutrients trapped inside.

Which global fleet of robotic floats dives to 2,000 metres every ten days to record ocean temperature and salinity?

Argo takes its name from the ship of Greek myth because the floats work hand in hand with the Jason satellites, which measure sea level from orbit. The programme has run since the early 2000s.

Which electrical property does the C stand for in a CTD probe, the workhorse instrument lowered from research ships?

Conductivity is how the probe measures salinity, and the T and D stand for temperature and depth. The depth reading itself is worked out from water pressure.

Which simple tool, created in 1865 by a priest and astronomer, is lowered until it vanishes to gauge water clarity?

The Secchi disk is a plain white circle 30 centimetres across, devised by the Italian Angelo Secchi. The depth at which it can no longer be seen is recorded as the water's transparency.

Which deep ocean layer acts as a waveguide, letting low-frequency sound travel thousands of miles before fading?

The SOFAR channel was first put to use in a project begun in the Second World War. The US Navy worked on locating small bombs that downed pilots could drop into the sea as distress signals.

Which sediment-laden underwater flow snapped transatlantic cables in sequence after a 1929 Newfoundland earthquake?

A turbidity current is a dense, muddy flow that runs downslope along the seabed. In 1929 the cables broke one after another, each farther from the epicentre, as it swept past them.

Which flat-topped undersea mountains did Harry Hess identify in 1945 and name after a 19th-century Princeton geographer?

Guyots were once volcanic islands, Hess argued, beheaded by wave action before ending up deep under the sea. Their flat summits can be more than 10 kilometres across.

Which metal did oceanographer John Martin propose adding to the sea to trigger algae blooms that absorb carbon dioxide?

Iron is so scarce in some waters that it holds back growth, Martin argued in the late 1980s. He linked dust blown off the continents, rich in the metal, to the cooling that led into past ice ages.

Which Vienna-born oceanographer helped devise the wave forecasts used for the Allied landings in Normandy on D-Day?

Walter Munk worked out the method with his doctoral advisor from 1943, and it supported beach landings in every theatre of the war. Poor wave conditions delayed D-Day itself by 24 hours.

Which unit, used for the transport of ocean currents, equals one million cubic metres of water flowing past each second?

The sverdrup is named after oceanographer Harald Sverdrup. All the world's rivers together pour only about 1.2 of them into the sea, while the largest ocean currents carry more than a hundred.

Which nickname do oceanographers give the mesopelagic layer, the home of bristlemouths, blobfish and the giant squid?

The twilight zone lies between the sunlit surface waters and the dark deep. Sound surveys suggest it holds 7 to 10 gigatonnes of fish, several times what net tows had indicated.