98 Fun Facts About Latitude and Longitude

Sailing-ship crews dreaded which belt close to the Equator?

The Doldrums. Ships were often becalmed there; 'in the doldrums' first meant low spirits, and the phrase was apparently later taken for the name of the place.

Lines of constant latitude are known as what?

Parallels. Unlike meridians, which all meet at the poles, these circles never touch: each stays the same distance from its neighbours all the way round the globe.

Much of the border between which two countries runs along latitude 49° north?

Canada and the US. An 1818 treaty ran the border west along it to the Rockies, and in 1846 the two sides extended the same line to the Pacific as a compromise, despite the cry of 'Fifty-four forty or fight'.

Because Earth bulges at the Equator, the summit of which mountain is the farthest point from Earth's centre?

Chimborazo. The Ecuadorian volcano stands one degree south of the Equator, so although Everest is more than 2,500 m taller above sea level, Everest's peak sits about 2 km closer to Earth's centre.

The 'm' in a.m. and p.m. stands for meridiem, the Latin for which time of day?

Noon. A meridian is literally a midday line: the Sun crosses yours at local noon, which is how the north-south lines of longitude came by the name.

What is the latitude of the North Pole?

90° N. Every meridian meets there, so the Pole has no longitude of its own, and whichever way you step from it you are heading south.

A one-hour difference in local solar time corresponds to what span of longitude?

15°. Earth turns through 360° every 24 hours, which is why a clock still keeping home time shows a navigator how far east or west the ship has sailed.

What do geographers call the point on Earth's surface diametrically opposite your own position?

The antipode. The word is Greek for 'with feet opposite (ours)', and it is why the British came to call Australia and New Zealand the Antipodes.

In which city was the 1884 International Meridian Conference held?

Washington, D.C. The delegates backed Greenwich with only one vote against, largely because nearly two-thirds of the world's ships already used charts based on it.

Which mountain, only about 330 km from the Equator, still carries glaciers on its summit?

Kilimanjaro. At 5,895 metres its summit stays cold enough for ice at a latitude where the lowlands are hot all year: climate follows altitude as well as latitude.

GPS puts 0° longitude not on Greenwich's famous courtyard line but roughly what distance to its east?

100 metres. The modern line runs about 102 m east of the old one because satellites measure from Earth's centre of mass, while the Greenwich telescope was levelled by local gravity.

Legend says ships becalmed around 30° north threw which animals overboard, giving those latitudes their name?

Horses. In the calm, dry 'horse latitudes' stalled crews ran short of water and are said to have sacrificed their cargo of horses to save it, one of several stories told to explain the name.

Which country abstained from the 1884 vote for Greenwich and kept its own time until 1911?

France. Even when it switched in 1911, the law avoided the word Greenwich, defining the new time as Paris mean time retarded by 9 minutes and 21 seconds.

Which ancient geographer's world map measured longitude from a prime meridian through the 'Fortunate Isles'?

Ptolemy. He set zero in the Atlantic, at the western edge of the world he knew, so that every place on his map lay to the east of it.

Who is generally credited with inventing the geographic coordinate system?

Eratosthenes. The Alexandrian librarian who coined the word 'geography' also worked out Earth's circumference from the shadows cast at two Egyptian cities.

Which continent is crossed by the Equator, the Tropic of Cancer and the Tropic of Capricorn?

Africa. The prime meridian crosses it too, so the continent has land in all four hemispheres, with about two-thirds of it lying north of the Equator.

What is the approximate length of the Equator?

40,000 km. The round figure is no accident: the metre was first defined in the 1790s as one ten-millionth of the distance from the North Pole to the Equator.

Despite its name, Equatorial Guinea misses the Equator; which nearby country does the line cross?

Gabon. Equatorial Guinea's mainland sits just north of the line and its island of Annobón lies south of it, so the Equator slips between them without touching either.

Counting land and sea together, which country straddles the greatest length of the Equator?

Indonesia. The line threads Sumatra, Borneo, Sulawesi and Halmahera and the seas between them, and on Borneo it runs through the city of Pontianak, which marks it with a monument.

The Equator is the only line of latitude that is also what?

A great circle. Its plane cuts Earth into two equal halves, and because great circles are the shortest routes on a globe, pilots plot their courses along them rather than along lines of latitude.

Why do rockets launched eastward from sites near the Equator, such as Kourou, need less fuel?

Earth spins fastest there. The ground moves east at about 460 metres a second, a free push for any rocket, which is why the US launches from Florida and Europe from French Guiana.

The prime meridian leaves Europe from the coast of which country?

Spain. The line crosses the Pyrenees, cuts across the Gulf of Valencia and leaves the coast for good near Calp, so a slice of eastern Spain lies in the Eastern Hemisphere and the rest in the Western.

At roughly what latitude does the Tropic of Cancer lie?

23.4° N. The figure is simply the tilt of Earth's axis, which makes this the farthest north that the midday Sun can ever stand directly overhead.

On which date is the Sun directly overhead at the Tropic of Capricorn?

The December solstice. Earth's southern half is then tilted most fully towards the Sun, so a flagpole on the tropic briefly casts no shadow, at the height of the southern summer.

The Tropic of Cancer is the southern limit of which alliance's mutual-defence obligation?

NATO. Its treaty covers members' islands only in the North Atlantic north of that line, which is why an attack on Hawaii would not oblige the other allies to respond.

North of which line does the midnight sun shine each summer?

Arctic Circle. On the line itself the Sun stays up for one full day; farther north the unbroken daylight lasts longer, until at the Pole the Sun stays up for about six months.

At about what rate is the Arctic Circle drifting towards the North Pole in the 21st century?

14.5 metres per year. Iceland's island of Grímsey marks the line with an eight-tonne stone sphere, which has to be moved to a new spot as the circle creeps north.

The word 'arctic' comes from the Greek name of which animal, after a constellation of the northern sky?

Bear. Greek arktos is the bear of Ursa Major, which circles the northern sky, so the Arctic is the region under the Bear and 'antarctic' simply means opposite to it.

Which king tested a longitude sea clock at his own observatory and pressed Parliament to pay its maker?

George III. After ten weeks of daily checks in 1772 he found it accurate to within a third of a second a day, and told its maker to petition Parliament for his reward.

Which unit of distance was originally defined as one minute of latitude?

The nautical mile. A degree of latitude is therefore 60 of them, about 111 km, which lets navigators measure distance straight off the latitude scale at the edge of a chart.

Which Yorkshire-born carpenter turned clockmaker built the sea clocks that solved the longitude problem?

John Harrison. He built five timekeepers over nearly four decades, yet was paid the last of his reward only at eighty, after years of dispute with the board that judged them.

What was the top reward on offer under the 1714 Longitude Act?

£20,000. The offer set off a rush of schemes from the greatest scientific minds and the humblest tinkerers alike, yet about fifty years passed before a sea clock met its terms.

What did H4, the timekeeper that solved the longitude problem, resemble?

A large pocket watch. Nobody then took watches seriously as precision timekeepers, yet this one, ticking five times a second, kept time within the strictest limits the 1714 Act had set.

Before sea clocks were common, navigators found longitude by measuring the angle between a star and which other body?

The Moon. It crosses its own width of sky about every hour, so it works like the hand of a clock, and from 1766 the Nautical Almanac printed tables to read the time from it.

Which astronomer first proposed timing the eclipses of a planet's moons as a clock for finding longitude?

Galileo. He offered the idea in pursuit of two longitude prizes; it was hopeless on a rolling deck but worked on land, where it later let surveyors correct the maps of whole countries.

Who patented the first working pendulum clock in the 1650s?

Christiaan Huygens. He built it in the hunt for a sea clock, and it transformed timekeeping on land, but his trials showed a pendulum could never keep time on a heaving deck.

Which explorer twice tried to find his longitude from lunar eclipses, with wildly inaccurate results?

Christopher Columbus. In Jamaica in 1504 he put the same eclipse to another use, predicting it in advance to frighten the islanders into feeding his stranded crew.

From which landmark did wireless time signals for ships begin broadcasting in 1910?

The Eiffel Tower. Built as a temporary exhibit and due to be dismantled in 1909, it was spared because it made such a useful radio mast, and its daily signals let ships reset their chronometers.

The International Date Line roughly follows which meridian?

180°. It lies exactly opposite the prime meridian in the mid-Pacific, but the line has no legal force, so it zigzags to keep island groups and Alaska's Aleutians on a single calendar day.

Crossing the date line eastbound does what to the calendar date?

Moves it back one day. Jules Verne built the ending of Around the World in Eighty Days on the effect: by circling the globe eastward, Phileas Fogg gains a day he hadn't counted and wins his bet.

Which island nation's Line Islands keep the most advanced clock time on Earth, UTC+14?

Kiribati. A mid-1990s shift swung the date line far to the east around these islands, so they now share Hawaii's clock time while running a full day ahead of it.

Which country deleted Friday 30 December 2011 from its calendar by jumping across the date line?

Samoa. It had crossed the other way in 1892 to suit American traders, then jumped back to share a working week with Australia and New Zealand, by then its biggest trading partners.

Which colony ran a day behind its Asian neighbours for 323 years until 1844?

The Philippines. It was reached and governed from Mexico, by ships sailing west across the Pacific, so it kept American dates until Tuesday, 31 December 1844 was struck from its calendar.

The International Date Line passes between the two Diomede Islands in which body of water?

The Bering Strait. Russia's Big Diomede and Alaska's Little Diomede lie about 4 km apart but 21 hours apart on the clock, which is why they are nicknamed Tomorrow Island and Yesterday Island.

What is the nickname for the point at 0° latitude, 0° longitude?

Null Island. Software that can't place an address often files it at 0°, 0°, so this empty patch of the Gulf of Guinea collects misplaced data from all over the world.

Which world's prime meridian runs through the small crater Airy-0?

Mars. The half-kilometre crater was picked from Mariner 9 photographs and named for George Airy, whose telescope at Greenwich defined Earth's own prime meridian.

Northern sailors long read their latitude from the height of which star?

Polaris. It sits almost directly above the North Pole, so its angle above the horizon nearly matches your latitude: overhead at the Pole, on the horizon at the Equator.

The grid formed by lines of latitude and longitude together is called what?

A graticule. On a globe its meshes narrow towards the poles, but a Mercator map straightens them into rectangles, which is why Greenland looks many times its true size there.

Which Jules Verne novel ends with a wager won because the traveller forgot the date line?

Around the World in Eighty Days has Phileas Fogg reach London sure he has lost, until it emerges that his party saw 80 sunrises while the city saw only 79.

Which mountain's summit is the farthest point from Earth's centre, thanks to the equatorial bulge?

Chimborazo sits less than two degrees south of the Equator, where the planet is widest, so it outreaches Mount Everest despite standing more than 2.5 km lower above sea level.

The line of latitude 38° N was chosen in 1945 to split which country into Soviet and American zones?

Korea was divided in a hurry: two young American officers, working on extremely short notice, picked the line off a National Geographic map.

Which river is the only major one to cross the Equator twice, in a great counter-clockwise arc?

The Congo drains land on both sides of the line, so some part of its basin is always in a rainy season and its flow stays unusually steady.

Which US state counts as both the westernmost and, by longitude, the easternmost in the Union?

Alaska's Aleutian Islands run so far west that they cross into the Eastern Hemisphere, which puts Semisopochnoi Island at the extreme east of American longitude.

Which star's height above the horizon roughly equals a northern observer's latitude?

Polaris appears due north to better than one degree, so its angle above the horizon gave sailors their latitude with no clock or long calculation needed.

Which unit of distance was originally defined as one-sixtieth of a degree of latitude?

The nautical mile was pinned to one agreed length only in 1929, because Earth's flattened shape makes that slice of latitude slightly longer at the poles than at the Equator.

Which capital city lies just south of the Mitad del Mundo, a monument built to mark the Equator?

Quito's monument honours an 18th-century French-led survey of the line, but modern satellite measurements put the true Equator almost 800 feet to the north.

Which is the only country crossed by both the Equator and the Tropic of Capricorn?

Brazil spans enough latitude to hold equatorial rainforest in its north and temperate conifer forest in its south, with tropical savanna in between.

Whose circumnavigation reached Cape Verde in 1522 with a log one day behind the local date?

Ferdinand Magellan's surviving crew had recorded every day of the three-year voyage without a gap, yet circling the globe had quietly cost them one sunrise.

Which continent is crossed by both the Equator and the prime meridian?

Africa straddles both lines, yet the two never meet on its soil: they cross out at sea, off the continent's western coast.

Which European capital sits at about 40° N, roughly level with Philadelphia and Beijing?

Madrid shares its latitude, to within a degree, with Naples and Ankara too, and the 40th parallel itself draws the border between the US states of Kansas and Nebraska.

Which country's coast lies closest to the point where the Equator meets the prime meridian?

Ghana's Cape Three Points is the nearest land to that spot, about 570 km out in the Gulf of Guinea, while the prime meridian comes ashore at the port city of Tema, near Accra.

Which Pacific country has roads that cross the antimeridian, half a world from the prime meridian?

Fiji keeps a single calendar date all the same, because the International Date Line swerves around the islands instead of following the meridian across Taveuni.

What name is given to the summer weeks north of the Arctic Circle when daylight lasts all 24 hours?

Midnight sun lasts longer the farther north you go, stretching to about six months of unbroken daylight at the North Pole itself.

What do sailors call the calm, dry belts about 30 degrees north and south of the Equator?

The horse latitudes are said to take their name from becalmed Spanish ships whose thirsty crews threw dying horses overboard, a popular tale that remains unproven.

Which 1569 map projection keeps compass courses straight but wildly inflates Greenland?

Mercator's map was built for sailors, and almost every marine chart still uses it, even though it shows Greenland as big as a continent 14 times its size.

Which hobby of hunting containers hidden at published coordinates began in Oregon in May 2000?

Geocaching began the day after the United States stopped degrading civilian satellite-navigation signals, which made a small hidden container findable for the first time.

The line of latitude 49° N forms a long, straight stretch of the border between which two countries?

Canada and the United States settled on the line in 1818 to avoid surveying a tangled watershed, though old boundary markers stray from it by up to half a mile.

Which Southeast Asian city sits just one degree, about 137 km, north of the Equator?

Singapore lies so near the line that it has no distinct seasons at all, just uniform heat, high humidity and abundant rain the whole year round.

Which Pacific island group straddles the Equator and shelters the only penguins living north of it?

The Galápagos Islands stay cool enough for penguins because the Humboldt Current bathes them in cold water, even though the Equator runs across Isabela Island.

Which island, the world's third largest, is cut roughly in half by the Equator?

Borneo is divided among three countries, and a monument near its city of Pontianak marks the place where the line crosses the island.

In which country does Santa Claus Village sit right on the Arctic Circle, just outside Rovaniemi?

Finland has a quarter of its territory north of the line, and at the country's northernmost point the summer Sun does not set for 73 days.

Which city, at about 41° S, is the world's southernmost capital of a sovereign state?

Wellington pays for its latitude in wind: it sits in the belt of strong westerlies and, averaging 27 km/h, is known as the world's windiest city.

Which city, at about 64° N, is the world's northernmost capital of a sovereign state?

Reykjavík holds the title on a technicality: Nuuk lies about 4 km farther north, but Greenland is not an independent state.

Which is the only US state in the tropics, where the Sun passes directly overhead twice a year?

Hawaii calls the moment Lahaina Noon, a name picked in a 1990s museum contest, when flagpoles and other upright objects cast no shadow.

Which country spans five geographical time zones yet runs every clock on a single official time?

China's far-western Xinjiang copes by also keeping a local time two hours behind, so shops there commonly open at 10:00 by the national clock.

Which country runs from 17° S to 56° S yet averages only about 175 km from east to west?

Chile's length of more than 4,300 km carries it from the Atacama, the world's driest desert, in the north to glaciers and a cool oceanic climate in the far south.

The Tropic of Cancer passes through the middle of which South Asian country?

India counts as climatically tropical on both sides of the line, helped by the Himalayas, which shut out cold Central Asian winds and keep the north unusually warm.

Which 1494 agreement divided new lands between Spain and Portugal along an Atlantic meridian?

The Treaty of Tordesillas put the line 370 leagues west of the Cape Verde islands, far enough out to hand Portugal the eastern bulge of South America.

Which British navigator led the first recorded crossing of the Antarctic Circle, in January 1773?

James Cook never once sighted Antarctica, though on that voyage his ships passed within about 120 km of the continent without anyone aboard knowing.

Before sea clocks, sailors estimated longitude from speed, heading and elapsed time by which method?

Dead reckoning builds each position on the one before, so its errors pile up over time; it was still the main guide to longitude on early Atlantic crossings.

Which handheld instrument do navigators use to measure the angle between the Sun and the horizon?

A sextant is named for its frame, a sector of about one-sixth of a circle, though its mirrors let it measure angles twice as wide as that arc.

Which constellation's long axis points navigators toward the south celestial pole?

The Southern Cross, the constellation on Australia's flag, works as a pointer: extend its long axis about four and a half times and you land close to the pole, where very few bright stars lie.

Which unit was first defined as one ten-millionth of the distance from North Pole to Equator?

The metre rests on a 1790s survey of the meridian between Dunkirk and Barcelona, corrected for Earth's slightly squashed shape.

Which scientist predicted Earth's flattened poles, later confirmed by a 1730s expedition to Lapland?

Isaac Newton was vindicated by a team measuring a degree of latitude near the Arctic Circle, among them Anders Celsius, later famous for his temperature scale.

Which naval nickname marks sailors who have crossed the Equator, unlike first-time pollywogs?

Shellbacks run the initiation as a mock Court of Neptune, while sailors who cross the Arctic Circle instead join the Order of the Blue Nose.

Which boundary, surveyed in the 1760s near 39°43′ N, came to divide America's North and South?

The Mason–Dixon line settled a royal blunder: Pennsylvania's charter wrongly assumed that latitude 40° N would touch a circle drawn twelve miles around New Castle.

What term names the point directly opposite a place on Earth, which for most land lies in ocean?

An antipode takes its name from the Greek for 'with feet opposite', picturing people who stand sole to sole with us on the far side of the globe.

Which US state reaches farther north than any other of the lower 48, thanks to an old map error?

Minnesota's Northwest Angle exists because treaty negotiators trusted a map that drew Lake of the Woods as a rough oval; by road it is reached only through Manitoba.

What do navigators call a path crossing every meridian at the same angle, spiralling poleward?

A rhumb line is easy to steer because the compass bearing never changes, but it is not the shortest route: on a long passage at 60 degrees north it runs about 8.5% longer.

In sky coordinates, right ascension stands in for longitude; which one stands in for latitude?

Declination ties the sky to the ground: a star passing directly overhead has a declination almost exactly equal to the observer's own latitude.

Which westernmost Canary Island served parts of Europe as the prime meridian for over 500 years?

El Hierro is still nicknamed Meridian Island; as the westernmost land known to ancient mapmakers, a zero line there kept every charted longitude positive.

Which Scottish-born rail engineer championed worldwide time zones after missing a train in Ireland?

Sandford Fleming missed it because a timetable printed p.m. for a.m.; he later pressed his scheme at the 1884 conference that settled the world's prime meridian.

Which author's 1995 bestseller 'Longitude' tells how a clockmaker solved navigation's great problem?

Dava Sobel's book was turned into a television drama in 2000, and it earned her a fellowship of the American Geographical Society.

Which British king spent ten weeks of 1772 testing a longitude timekeeper, then backed its maker?

George III found it accurate to within a third of a second a day, and threatened to go to Parliament in person to see its elderly maker rewarded.

Which desert tract between Egypt and Sudan is claimed by neither, thanks to a dispute over 22° N?

Bir Tawil is left over because each country backs the boundary that would give it the Halaib Triangle instead, an area that both of them claim.

Which islands wrecked a British fleet in 1707, a disaster long tied to the longitude problem?

The Isles of Scilly wreck killed up to 2,000 sailors, yet longitude was not the only culprit: later analysis also blamed uncorrected compass variation and errors in the charts and pilot books.

Which ship's mutineers carried off the K2 sea clock in 1789, a timekeeper built to find longitude?

HMS Bounty's clock resurfaced in 1808, when an American captain who came upon Pitcairn Island was handed it by the last surviving mutineer.

Besides Colorado, which US state is bounded by just two lines of latitude and two of longitude?

Wyoming's borders were written into law as pure coordinates, but 19th-century surveyors wandered, so the legal boundary deviates from the true lines in places.