The Pacific Ring of Fire Explained

By Quake Tracker Live Editorial · Published November 9, 2026

The Pacific Ring of Fire is the horseshoe-shaped belt of earthquakes, volcanoes and ocean trenches that surrounds the Pacific Ocean. The USGS says about 90 percent of the world's earthquakes occur there, and about 81 percent of the planet's largest ones. The reason is plate tectonics: the Pacific Plate and several smaller plates meet the surrounding continents along one almost continuous boundary, and most of it is a subduction zone.

Where is the Ring of Fire?

NOAA describes the ring as running from Chile north through Central America and Mexico, up the U.S. West Coast and Alaska, then west and south through the Aleutian Islands, Kamchatka, Japan, the Philippines and Indonesia toward New Zealand. It is not a perfect circle: it is a chain of boundaries between the Pacific Plate (and plates such as Nazca, Cocos, Juan de Fuca and the Philippine Sea Plate) and the plates that surround them.

You can follow activity in many of these places on our site. For example, see Japan, Chile, Indonesia, the Philippines, Mexico, New Zealand and the U.S. states of Alaska, California and Oregon.

Why so many earthquakes and volcanoes?

Most of the ring is made of subduction zones, where oceanic crust is dense enough to sink into the mantle under another plate. Two things follow from that.

• Earthquakes. The boundary between the plates (the megathrust) locks, builds strain and then slips. These megathrust faults are the only ones known to produce earthquakes larger than about magnitude 8.5. Earthquakes also occur inside the sinking slab, at depths down to several hundred kilometers (see earthquake depth explained), and in the crust of the upper plate.
• Volcanoes. As the plate sinks, it releases water into the mantle above it, which lowers the melting point of the rock and creates magma. That magma rises to feed chains of volcanoes, such as the Cascades, the Andes, the Aleutians and the Japanese islands.

Not every part of the ring works the same way. In California, the plates slide past each other sideways along the San Andreas system rather than diving, which still means frequent and strong earthquakes (see the San Andreas Fault explained). In the north of New Zealand and in Alaska, subduction dominates.

How big a share of the world's earthquakes?

The USGS gives two figures that are easy to mix up. About 90 percent of the world's earthquakes happen in the Ring of Fire. About 81 percent of the largest earthquakes happen there too. The other main belt, the Alpide belt, which runs from Indonesia through the Himalayas and the Mediterranean, accounts for about 17 percent of the largest earthquakes.

The largest earthquakes of the Ring of Fire

The biggest earthquakes ever recorded all come from the ring. Magnitudes below are moment magnitudes from the USGS catalog; see our full guide to the largest earthquakes in the world.

Tsunamis and the ring

NOAA reports that about 78 percent of tsunamis originate in the Pacific Ocean, around the Ring of Fire, and that tsunami hazard is greatest near subduction zones. Large earthquakes there and the landslides they trigger can send waves across the whole ocean. The 1700 Cascadia earthquake, for instance, was dated from a tsunami recorded in Japan.

Volcanoes on the ring

The USGS counts about 1,350 potentially active volcanoes worldwide and notes that many of them are along the Pacific Rim. A widely repeated number is that the ring holds roughly three quarters of the world's active volcanoes, but we could not confirm it on a USGS page, so treat it as approximate. What is certain is that volcanic arcs follow the subduction zones all around the Pacific, from the Andes to the Cascades, the Aleutians, Kamchatka, Japan and Indonesia.

Are earthquakes and eruptions linked?

They come from the same plate motion, but one does not directly cause the other in a predictable way. A large earthquake can sometimes change stress near a volcano, and volcanic unrest produces its own earthquakes, such as the magnitude 6.9 earthquake in Hawaii in 2018 that came with Kilauea's eruption. But being on the Ring of Fire does not mean a volcano will erupt after an earthquake, and neither can be predicted by the other.

Common misunderstandings

• It is not a single fault. The ring is a chain of many separate plate boundaries, each with its own speed, geometry and history. A great earthquake in Chile does not cause one in Japan.
• It is not only volcanoes. Most of the shaking comes from faults at plate boundaries, and most of the ring's large earthquakes happen offshore.
• Being outside the ring does not mean being safe. About 10 percent of earthquakes occur elsewhere, and large ones do too, as the Alpide belt shows.
• Quiet years do not mean the ring has switched off. Strain keeps building on locked segments whether or not a large earthquake has happened recently.

Living on the ring

Hundreds of millions of people live around the Pacific, and the countries on it have invested heavily in building codes, tsunami warning and public education. Whether you live on the ring or visit, the same steps apply: know how to protect yourself (see what to do during an earthquake) and, near coasts, know the natural signs of a tsunami and your route to high ground. For live activity, open the biggest recent earthquakes or the today page: most of the large events you will see listed fall along the ring.

Frequently asked questions

Sources and further reading

• USGS: Where do earthquakes occur?
• USGS: Cool earthquake facts
• USGS: How much of the Earth is volcanic?
• NOAA JetStream: Tsunami locations

This guide is general information, not professional or emergency advice. Quake Tracker Live is not an official warning system; follow instructions from local authorities.