The Bermuda Triangle is a patch of the Atlantic Ocean, out at sea between Florida, Puerto Rico and the island of Bermuda. For many years people have told stories and written books about it. The name has a known beginning. It comes from a 1964 magazine article by a writer named Vincent Gaddis. A good way to start is with plain questions. Where exactly is it? What is it? The answers begin with a map of the ocean and its three corners.

Gaddis drew the Triangle by joining three points: Florida to Bermuda, Bermuda to Puerto Rico and Puerto Rico back to Florida. Most modern maps follow his description. One corner of the shape is the island of Bermuda. Bermuda is a British overseas territory in the North Atlantic. Its nearest land is Cape Hatteras, North Carolina, about 640 miles (1,030 km) away.

Ask where the Bermuda Triangle ends, and the answer changes. Its edges are loosely defined: it is roughly the sea between Florida, Bermuda and Puerto Rico, and writers draw it a little differently. No official maps mark its boundaries. The U.S. Board on Geographic Names does not recognize the name or keep an official file on the area. Even so, people give it a size. The area people call the Bermuda Triangle covers about 500,000 square miles (1.3 million square kilometers) of ocean.

Many ships and planes travel through the Bermuda Triangle, so it is a busy part of the ocean. The Triangle area is one of the most heavily traveled regions in the world. With more ships and planes, the odds that something goes wrong for some of them are greater. The sea is also very large. Earth's seas cover about 70 percent of the planet and average about 12,100 feet (3,700 meters) deep, so a lost boat or plane can leave little to find.

Government agencies give a different kind of answer. NOAA, the U.S. ocean science agency, says there is no evidence that unexplained trouble happens more often in the Bermuda Triangle than in other busy parts of the ocean. The U.S. Navy and U.S. Coast Guard say there are no supernatural explanations for disasters at sea, and that nature and human mistakes together explain them. A skeptical writer says the U.S. Coast Guard does not treat the Bermuda Triangle as an area of special danger to ships or planes.

The water itself is part of the picture. The Caribbean has many islands, and they make wide areas of shallow water that can be hard for big ships to steer through. The Gulf Stream is a stream of warm water that moves through the Atlantic Ocean. It carries warm water north along the coast of Florida and then across the Atlantic Ocean. So ships and planes cross a sea that has both shallow places and a moving river of warm water.

The Gulf Stream is a fast mover. It flows at about 4 miles per hour on average, and up to about 5.6 mph near the surface. It also carries more water than all of the world's rivers combined. NOAA says the Gulf Stream can cause rapid, sometimes violent changes in weather. Rapid changes mean the weather can turn from one kind to another in a short time.

Storms cross the Triangle too. According to NOAA, most Atlantic tropical storms and hurricanes pass through the Bermuda Triangle area. A hurricane is a big storm with strong winds that forms over warm ocean water. A storm is called a hurricane when its winds reach 74 miles per hour. Atlantic hurricane season runs from June 1 to November 30. Before weather forecasts got better, ships in the area had less warning about storms than ships have today.

The Triangle became famous through books. A 1974 book by Charles Berlitz became a best seller and made the Bermuda Triangle famous. Berlitz's book claimed the lost city of Atlantis was somehow behind the disappearances. Dozens more books followed it. The Atlantis idea is one answer that a writer gave to the question of what the Triangle is.

Put the pieces together and the Bermuda Triangle is a name from a 1964 magazine article. It is a shape drawn by joining three points. Its edges are loosely defined, and writers draw them a little differently. It covers about 500,000 square miles of a busy ocean. The question worth keeping is how you would tell whether a busy place has more trouble than other busy places, and what kind of evidence you would need to decide.

Words to know

• territory: overseas land
• boundaries: edges
• supernatural: beyond nature
• hurricane: big ocean storm