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Ocean Trivia

Dive deep into mind-blowing ocean facts that will amaze you! From the deepest trenches to the largest creatures - discover incredible marine secrets that will fascinate every ocean lover.

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Questions (125 of 125)

🟡medium

Which metal accumulates in tuna and can pose health risks if consumed in high amounts?

🔴hard

The oldest known oceanic crust sampled directly is about how old from the eastern Mediterranean Herodotus Basin?

đŸŸĸeasy

Which crustacean is known for a snapping claw that makes a loud pop underwater?

đŸŸĸeasy

Which floating system cleans plastic by using ocean currents to funnel debris?

🔴hard

Which rare fish was first described from a submersible at about eight hundred meters near Hawaii in 2009?

🔴hard

What is the accepted boundary latitude for the Antarctic Convergence where subantarctic and polar waters meet?

đŸŸĸeasy

What predator has the largest recorded great white shark bite force estimates among bony fish and sharks?

🟡medium

Which ancient Egyptian port on the Red Sea dispatched voyages to Punt?

🔴hard

Which basin hosts the deepest hydrothermal vents known to date?

🔴hard

What is the practical salinity unit definition based on conductivity relative to a standard solution?

🟡medium

What is the main mineral structure of coral skeletons?

đŸŸĸeasy

Which ocean trench runs parallel to the west coast of South America?

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Which volcanic island emerged dramatically near Tonga in 2015 then eroded again?

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What was the name of the submersible used by Robert Ballard to explore hydrothermal vents in 1979?

đŸŸĸeasy

What phenomenon can produce a sudden large sea wave after an undersea quake?

đŸŸĸeasy

What common beach safety feature shows where it is safe to swim between two colored markers?

🟡medium

Which ship used by Charles Darwin surveyed the coasts and oceans in the 1830s?

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Which sea is the saltiest open sea due to high evaporation and limited inflow?

🔴hard

Which polymetallic structure at vents is rich in copper zinc and precious metals formed by precipitating sulfides?

🟡medium

Which expedition located the wreck of RMS Titanic in 1985?

🟡medium

The thermohaline circulation is driven by differences in what properties?

đŸŸĸeasy

Which marine reptile returns to beaches to lay eggs?

🔴hard

Which deep sea jellyfish displays a spectacular bioluminescent pinwheel when disturbed?

🔴hard

What is the estimated global mean sea level rise from nineteen hundred to two thousand according to tide gauges?

🔴hard

Which spectral absorption band gives seawater its characteristic blue by absorbing red strongly?

đŸŸĸeasy

Which ocean lies between the Americas and Europe Africa?

🟡medium

Which global agreement regulates ocean dumping of wastes since 1972?

🔴hard

Which hydrothermal vent field discovered in 2000 features carbonate chimneys up to sixty meters tall?

🟡medium

In what year did James Cameron pilot Deepsea Challenger to the bottom of Challenger Deep?

🟡medium

Which underwater mountain chain is the longest on Earth?

đŸŸĸeasy

Which ocean is the largest single body of water on Earth by surface area?

🔴hard

Which autonomous vehicle mapped the Endurance shipwreck beneath Weddell Sea ice in 2022?

đŸŸĸeasy

Which current helps keep western Europe milder in winter?

🟡medium

What is the name of the large floating iceberg that calved from the Larsen C ice shelf in 2017?

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The 2011 Tohoku earthquake generated a Pacific wide tsunami. What approximate maximum run up was recorded at Miyako?

đŸŸĸeasy

What name is given to the warm periodic ocean event that alters weather globally?

🔴hard

The Drake Passage sill depth that constrains circumpolar flow is approximately what?

🔴hard

Which rare deep sea ecosystem relies on methane oxidation at cold seeps?

đŸŸĸeasy

Which polar bear hunting ground depends on seasonal ocean ice?

🔴hard

The deepest known living fish observed in 2023 belonged to which genus?

🟡medium

Which current forms a ring that circles Antarctica and links all major basins?

đŸŸĸeasy

Which ocean surrounds Antarctica on all sides?

🟡medium

Which ocean desert region is known for extremely low nutrients and clear water in the North Pacific?

🔴hard

What is the approximate global mean mixed layer depth in meters averaged annually outside polar regions?

đŸŸĸeasy

Which structure protects a harbor by breaking waves?

đŸŸĸeasy

What color does seawater often appear in the open ocean due to light absorption and scattering?

đŸŸĸeasy

What famous Australian feature is the largest coral reef system?

đŸŸĸeasy

Which famous line on maps marks zero degrees longitude and meets the ocean near the English Channel?

đŸŸĸeasy

What is the term for zones with little oxygen that can form in coastal seas?

🔴hard

Which instrument on the Argo float measures conductivity to infer salinity at set depth levels?

🟡medium

Which country established Papahanaumokuakea Marine National Monument in 2006?

🟡medium

What is the approximate mean depth of the world ocean?

đŸŸĸeasy

What creates the rise and fall of ocean tides most strongly?

🟡medium

The highest recorded significant wave height from a buoy exceeded what value near Campbell Island in 2018?

đŸŸĸeasy

Which fish is famous for its dorsal fin and speed as the fastest in the ocean?

🟡medium

Which ridge spreading center runs through the Red Sea?

đŸŸĸeasy

What shallow tropical sea is famous for bright clear waters and many islands between Florida and Cuba?

🟡medium

What is the term for the zone of rapidly decreasing light with depth below the surface layer?

🔴hard

What is the approximate residence time of chloride ions in the ocean based on geochemical budgets?

🟡medium

Which species undertakes the longest known migration of any sea turtle?

đŸŸĸeasy

What floating line marks the level where waves meet the shore at that time?

đŸŸĸeasy

Which island nation sits on the Mid Atlantic Ridge and uses geothermal power from undersea spreading?

🔴hard

Which region exhibits the strongest open ocean nitrogen fixation by Trichodesmium colonies?

🔴hard

The largest marine protected area by size as of the mid 2020s is which region?

🔴hard

Which trace gas emitted by oceanic phytoplankton seeds cloud condensation nuclei in the marine boundary layer?

🟡medium

In 1960 the first photograph of life on the hadal seafloor showed what organism on the bottom?

đŸŸĸeasy

What do sailors call a powerful rotating ocean storm in the North Atlantic?

🟡medium

The exclusive economic zone gives a coastal state rights over resources up to how far from shore?

🔴hard

Which rare metal is enriched in ferromanganese nodules and is targeted for potential deep sea mining?

🟡medium

What famous encounter zone in the North Atlantic is known for shipwrecks near Bermuda?

đŸŸĸeasy

Which marine mammal is the largest animal known to have ever lived?

🔴hard

Which law describes the logarithmic dependence of wind driven current on depth known as the Ekman spiral?

🔴hard

Which ocean color pigment index is used to estimate phytoplankton biomass from space?

đŸŸĸeasy

Which ocean is smallest by surface area?

đŸŸĸeasy

What term describes the place where a river meets the sea with mixed salinity?

🔴hard

The Atlantic Meridional Overturning Circulation includes which deep current flowing southward?

🟡medium

Which nation completed the first full surface circumnavigation by sail in 1522 through the Magellan Elcano voyage?

🟡medium

Which strait separates Asia from North America at its narrowest point?

🟡medium

Which sea has the world lowest natural point on land at its shore?

🔴hard

What is the approximate density of typical seawater at the surface in kilograms per cubic meter?

đŸŸĸeasy

What is the primary salt in seawater by mass?

🔴hard

What is the official name of the deepest point in the Atlantic Ocean?

🔴hard

Which current forms from the retroflection of the Agulhas and leaks warm salty water into the Atlantic?

🔴hard

What is the approximate global ocean heat uptake since the mid 20th century expressed as zettajoules?

🔴hard

What is the typical pH of modern surface seawater averaged globally?

🔴hard

Which acoustic frequency band is most often used for long range submarine communication due to low attenuation?

🟡medium

Which bay sees the world highest tidal range recorded at over sixteen meters?

🔴hard

Which isotope ratio in foraminifera tests is used to reconstruct past seawater temperatures via paleothermometry?

🟡medium

What is the name of the warm current that flows north along Japans coast?

🟡medium

The Sargasso Sea is bounded not by land but by what?

đŸŸĸeasy

Which boundary sees waves crash directly onto steep cliffs along western Ireland?

🟡medium

The first crewed visit to the deepest ocean point was made by Trieste. Who were aboard?

đŸŸĸeasy

What device do ships use to determine ocean depth by sound?

đŸŸĸeasy

Which narrow waterway connects the Mediterranean Sea to the Atlantic?

đŸŸĸeasy

Which ocean borders the east coast of Africa and the west coast of Australia?

🔴hard

In which year did the International Hydrographic Organization formally recognize the Southern Ocean as a distinct fifth ocean in its publication?

🔴hard

Which seafloor observatory network off Canada provides real time data from cabled nodes?

🔴hard

What is the geologic term for a flat topped seamount that was once an island?

🔴hard

The Munk layer in underwater acoustics refers to what specific feature?

đŸŸĸeasy

Coral reefs are built primarily by which tiny animals?

🔴hard

What is the formal name of the slow equatorial wave that moves eastward and resets Pacific conditions before El Nino?

🔴hard

What was the measured maximum depth of Challenger Deep from Victor Vescovos 2019 Five Deeps expedition using pressure corrected readings?

🟡medium

What is the largest known submarine canyon on Earth by volume and length?

🔴hard

The FeMo cofactor essential for marine nitrogenase contains which heterometal cluster?

🔴hard

The slowest spreading ridge on Earth is which system?

🟡medium

What is the name of the algae responsible for many harmful red tides in coastal waters?

🔴hard

Which satellite altimetry mission pair first mapped global sea surface height with centimeter precision in the 1990s?

đŸŸĸeasy

Which sea connects to the Red Sea through a man made canal opened in 1869?

đŸŸĸeasy

Which legendary lost shipwreck is associated with a 1912 iceberg collision?

đŸŸĸeasy

Which animal is famous for long songs heard across ocean basins?

🔴hard

What is the formal name of the legal concept that governs the seabed beyond national jurisdiction for the benefit of humankind?

🔴hard

Which seafloor feature records magnetic reversals and was key evidence for seafloor spreading?

🟡medium

Which deep sea fish is known for a bioluminescent lure protruding from its head?

🟡medium

What is the accepted average salinity of seawater in practical salinity units?

🔴hard

The extreme pressure at eleven thousand meters is approximately how many atmospheres?

đŸŸĸeasy

What name is given to floating rafts of seaweed that create habitat in the North Atlantic?

🔴hard

What is the maximum recorded speed of the Agulhas Current measured by drifters and ADCPs?

🔴hard

The largest known submarine slide in the Atlantic during the Holocene is what event?

đŸŸĸeasy

Which floating ice feature breaks off from glaciers and drifts at sea?

🔴hard

Which statistical distribution often models wave heights where energy is random and linear?

🟡medium

The Great Pacific Garbage Patch is concentrated by which circulation feature?

🟡medium

The Dardanelles connects the Aegean to which inland sea?

đŸŸĸeasy

What gas do phytoplankton release that supports life on land and sea?

đŸŸĸeasy

What is the deepest known point in the ocean discovered so far?

🟡medium

What is the name of the rapid cold current along the west coast of South America that supports rich fisheries?

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