Explained
The Pacific Ocean is the largest and deepest ocean on Earth. It spans 60 million square miles from California to China, and in certain regions extends tens of thousands of feet below the surface of the water.
To get a sense of just how immense the Pacific Ocean is, you could put all of Earth's landmasses together, and the Pacific would still be larger.
The name Pacific is a version of pacify or peaceful. It was named by the explorer Ferdinand Magellan in 1520 as he sailed through a calm patch of water on the ocean. Despite its name, the Pacific is a vast body of water teeming with activity. Much of the ocean is still waiting to be explored, but human activities like industrial fishing, deep-sea mining, and fossil-fuel burning are already changing it in significant ways. The vast body of water is home to some of the most unique life forms on Earth and contains the deepest reaches known to humankind.
The Pacific Ocean stirs up some of the strongest hurricanes ever seen. For example, in 2018 the strongest storm of the year was Super Typhoon Mangkhut. It hit the Philippines in late September before dissipating over mainland China. At its strongest, the storm’s winds topped 165 miles per hour, uprooting trees, destroying homes, and causing deadly mudslides.
Hurricanes, typhoons, and cyclones are actually different names for the same weather pattern. Hurricane is used in the eastern Pacific, typhoon in the northwestern Pacific, and cyclone in the southwestern Pacific. The storms feed on the energy of warm water, making the Pacific a powerful breeding ground for them.
The Pacific basin is called the “Ring of Fire” because of the area of earthquake and volcanic activity around its edges. The resulting chain of volcanoes is roughly 25,000 miles long and springs to life where the Pacific tectonic plate slides against or collides into the other tectonic plates that circle it. The subduction of tectonic plates—when a plate slides beneath another one—in certain areas also helps form deepwater trenches.
The Mariana Trench is one such deep ocean trench that sits along the Ring of Fire in the Mariana Archipelago east of the Philippines. It's the deepest known spot on the planet—deeper than Mt. Everest is tall, reaching down roughly seven miles. The deepest point in the trench is called Challenger Deep, at 36,000 feet down.
Humans descended into the Challenger Deep in 1960 inside a U.S. Navy submersible, and film director and explorer James Cameron made a solo trip in 2012. Today, scientists periodically send remotely operated vehicles to the bottom of the trench for various research purposes.
Scientists are just beginning to learn about life in the deepest parts of the oceans. Creatures in the deep sea exist in waters with zero light, crushing pressure, and conditions no human could ever survive. Yet the deep sea is home to a diverse group of sea creatures with mysterious lives, from glowing lures to huge eyes. Scientists know little about many of these creatures and the roles they may play in the global ecosystem because they are so hard to study.