How high does the high tide go? In the Bay of Fundy, Canada, the difference between high and low tides is more than 16 metres. But at several points in the world’s oceans, called the tidal nodes, the sea level doesn’t change at all.
How do you measure ocean flow? One sverdrup equals a million cubic metres of water per second. All of the world’s rivers emptying into the ocean is 1.2 sverdrups; the largest current in the world is more than a hundred times larger.
The USS Johnston was sunk in the Battle off Samar in World War II. Its wreck descended into the Philippine Trench, the third deepest trench in the world, and we know of no deeper wrecks.
A strange honeycomb pattern appears on sea ridges around the world. We think that it is created by living creatures, but no-one has ever seen one. Oh, and there are fossils of the patterns going back 500 million years.
Princess Anne and Prince Ludwig of Löwenstein-Wertheim-Freudenberg liked flying and spying, respectively. Both disappeared under mysterious and separate circumstances.
We’ve all heard of the Dead Sea, so salty that people naturally float in it. But the Gaet’ale Pond in Ethiopia is saltier, and the Don Juan Pond in Antarctica is so salty that it doesn’t freeze, even at -50°C.
In 1959, a block of glacier ice was carried – without refrigeration – from the Arctic Circle, through Europe, across the Sahara, and all the way to the Equator. It was perhaps the greatest publicity stunt in history.
Every year in late February and early March, at the South Pole research station, the last flight leaves and the last sun sets. Neither will return for months. How do you mark such an occasion? With a horror film festival, of course.
Up until the 15th century, you could apparently walk from India to Sri Lanka. Rama’s Bridge is a short chain of limestone islands and shoals with a very fraught religious and political history.
In World War II, it was standard practice to add nonsense phrases to coded messages in transit, in order to thwart decryption efforts. One of those phrases accidentally changed the course of the largest naval battle in history.
Where do old spacecraft go to die? Into a graveyard orbit, or into the middle of the Pacific Ocean.
Continents move – we know this. The Atlantic is growing thanks to the expansion of the Mid-Atlantic Ridge. But in the future the ridge may start subducting. And with it, the Atlantic may become an inland sea.
I write about blood a lot. Sorry. But there’s a waterfall in Antarctica that is the colour of blood. And it has some interesting implications for astrobiology and extinction event survival.
Sailing around the end of South America, you steer around what you think is Cape Horn. But instead of open ocean there’s a surprise island dead ahead. You’re about to be shipwrecked thanks to the False Cape Horn.
Around 1311 CE, the mansa (sultan) of the Mali Empire sent hundreds of ships to find the other side of the Atlantic Ocean. They were lost at sea, so on the next expedition he sailed into the Atlantic himself. He was never seen again.