The “Ring of Fire” is the name that is often used to refer to the geology of the Pacific Rim. The Ring of Fire is an area of relatively intense seismic activity. The vast majority of the earthquakes and volcanic eruptions in the world occur along the Ring of Fire.
The Ring of Fire almost completely encircles the Pacific Ocean. It starts in New Zealand, runs up through the islands around Australia (not including that continent), to Indonesia and the Philippines. It then runs up through Japan and around the coast to North America. It then runs down the entire coasts of North and South America. These areas are very seismically active because they are areas in which various oceanic plates are being subducted under continental plates. This subduction leads to the creation of volcanoes and of faults where earthquakes can occur.
There have been many major earthquakes and volcanic eruptions around the Ring of Fire. There was, for example, the eruption of Mt. Tambora in 1815. This was the most violent volcanic eruption ever recorded. More recently, there were the earthquakes that caused the Indian Ocean tsunami of 2004 and the tsunami that led to the nuclear disaster in Japan in 2011.
The “Ring of Fire” is a description of the geographic and geologic characteristic of a vast region encircling the Pacific Ocean. The large number of countries, extending from the southern tip of South America and forming a large arc encompassing the entirety of the ocean’s shores, including the western coast of the United States and Canada, the eastern shores of the Russian Far East, much of Asia, and ending at Australia and New Zealand, encircle the Ring of Fire, which gets its name from the 25,000 mile long ring of volcanoes and oceanic trenches. As the current continents began to form 200 million years ago, many of the plates that form the Earth’s surface converged in the Pacific realm. The plate movement that occurred involved a number of smaller plates slipping underneath the larger plates, for example, the Juan de Fuca Plate was submerged beneath the North American plate, and the Nazca and Cocos Plates were similarly submerged beneath the South American Plate. The effects of all of this plate activity was to create an extremely unstable region where earthquakes are far more common than any other region of the planet, with massive tidal waves, or tsunamis, sometimes being created from larger quakes.
While earthquakes and tremors have affected other parts of the United States – the August 23, 2011 quake that shook Washington, D.C., for example – the reason that California is the location of the largest earthquake region in North America is because of the presence of the San Andreas Fault running north-to-south along the state’s length. That fault, as well as the presence of the Mount St. Helen volcano in Washington State, which erupted in 1980, scattering ash for thousands of miles, are directly attributable to the tectonic activity that is characteristic of the Pacific Ring of Fire. Similarly, active volcanoes in the Philippines, Indonesia, Hawaii, Alaska, Costa Rica, Japan, and Mexico are all physical manifestations of the geological structure of the Ring of Fire. With active lava flows and the ever-present threat of an eruption at one of these major volcanic regions, the designation of this formation as the “Ring of Fire” makes perfect sense.