The Pacific Ocean
The Pacific is the biggest and deepest ocean on Earth. It covers nearly a third of the entire planet, more than all of the continents put together. The Pacific is so big that it has its own time-keeping, its own weather patterns, and even its own circle of volcanoes around the edge called the Ring of Fire.
- Surface area168.7 million km²Bigger than every continent combined
- Average depth4,011 mDeepest of all oceans
- Deepest pointMariana Trenchapprox. 10,935 m down, deeper than Everest is tall
- % of EarthAbout 30%Of the whole planet's surface
- Countries on itOver 50From Chile to China to Australia
- Famous featureThe Ring of Fireapprox. 75% of the world's volcanoes line its edge
How does it compare to the other oceans?
Surface area in millions of km².
The Pacific is twice the size of the Atlantic, the second-biggest ocean. You could fit Africa, Antarctica, North America and South America into the Pacific and still have room left over.
What is the Pacific Ocean?
The Pacific Ocean is the body of salty water that stretches from the Arctic Ocean in the north to the Southern Ocean around Antarctica, and from the Americas in the east to Asia and Australia in the west. It was named by the Portuguese explorer Ferdinand Magellan in 1520 when he sailed into it from the stormy waters around the tip of South America. He called it "Mar Pacifico", which means "peaceful sea", because the waters felt calm. (He was lucky. The Pacific can be just as stormy as any other ocean.)
The Ring of Fire
The edge of the Pacific Ocean is one of the most geologically active regions on Earth. A horseshoe-shaped chain of volcanoes called the Ring of Fire runs from the southern tip of South America, up the western coast of the Americas, across to Alaska, down through Japan, the Philippines, Indonesia and New Zealand. The Ring of Fire contains approx. 75% of the world's active volcanoes and is the site of approx. 90% of the world's earthquakes.
The Ring of Fire exists because the floor of the Pacific Ocean is one giant tectonic plate (the Pacific Plate) that is slowly being pushed under the other plates around its edge. The pressure causes earthquakes and the friction melts rock into magma, which feeds the volcanoes.
The Mariana Trench
The deepest place on Earth is in the Pacific Ocean. It is called the Mariana Trench and lies just east of the Mariana Islands. The deepest point of the trench is called the Challenger Deep, and it goes down approx. 10,935 metres below sea level. The pressure at the bottom is over 1,000 times atmospheric pressure: enough to crush almost any submarine ever built. And yet there are still living things down there, including small white shrimp-like creatures and microbes that thrive in the dark.
Wildlife of the Pacific
The Pacific is home to a huge variety of life. The Great Barrier Reef off Australia is one of the largest living structures on Earth. The reefs around the Coral Triangle (a region between Indonesia, the Philippines and Solomon Islands) contain the highest variety of marine species on the planet. Larger animals include blue whales (the biggest animal ever to live), humpback whales, sharks, giant manta rays, sea turtles, and the elusive giant Pacific octopus.
Deeper dive: ocean currents, El Niño and Pacific exploration
The Pacific Ocean drives much of Earth's climate through its massive system of currents. The North Pacific Gyre is a giant circular current rotating clockwise, while the South Pacific Gyre rotates anticlockwise. These currents move enormous amounts of heat around the planet. The Kuroshio Current off Japan and the California Current off the western United States are two of the most important. The Kuroshio carries warm water from the tropics up to Japan and helps moderate the climate of the northern Pacific.
Every few years, the surface waters of the central and eastern Pacific become unusually warm, an event called El Niño. The opposite (when those waters become unusually cool) is called La Niña. Together they form the El Niño-Southern Oscillation (ENSO) climate pattern, which influences weather around the world. El Niño years tend to bring drought to Australia and Indonesia, heavy rain to Peru and California, and warmer winters to parts of North America. La Niña does roughly the opposite.
The Pacific has played a central role in human history and exploration. Polynesian sailors reached almost every inhabitable Pacific island by 1200 AD using stick charts, star navigation and detailed observation of waves and birds, a feat of seamanship not matched until the modern era. European exploration of the Pacific began with Vasco Núñez de Balboa's sighting of the eastern Pacific in 1513, followed by Magellan's circumnavigation (1519 to 1522), Cook's voyages (1768 to 1779) and many others. The Pacific Theatre of World War II (1941 to 1945) saw some of the largest naval battles in history. Today the Pacific Rim economies (China, Japan, the United States, South Korea, Australia, Indonesia and many others) together produce most of the world's manufactured goods.
The next-biggest ocean is the Atlantic. The warmest is the Indian Ocean. The smallest is the Arctic Ocean.