The “Ring of Fire” refers to the physical geography of the region surrounding the Pacific Ocean, specifically, the undersea faults created by plate tectonics and the string of volcanoes that runs the 25,000 mile length of what is called “the Pacific Rim.” Its significance lies in its inherently unstable structure, which results in the greatest concentration of earthquakes and volcanic activity in the world.
As the current continents formed 200 million years ago, the shifting plates in the region of what is now the Pacific Ocean pressed into each other, with smaller plates sliding under larger one. The resulting formations created the arc that runs along the western coasts of North and South America, the Russian Far East and China, and under Japan and Indonesia and ending several thousand miles off of Australia’s coast, and under New Zealand. The large number of active volcanoes in Chile, Mexico, Mexico, Central America, Washington State, Alaska, Japan, the Philippines, Indonesia and New Zealand give the arc its designation as the “Ring of Fire.”
While major eruptions of active volcanoes are relatively rare, lava flows are active throughout the Pacific Basin and the volcanoes in Washington State and the southern Philippine island of Luzon have erupted in relatively recent years. The more constant threat to humanity lies in the large number of earthquakes that occur along the Ring of Fire, evident in the 2004 undersea earthquake and resulting tsunami that devastated portions of Asia, killing an estimated 150,000 people and leaving hundreds of thousands more homeless. Similarly, the 2011 undersea earthquake and tsunami that struck northeastern Japan caused considerable damage, including to the Fukushima nuclear power plant.
The Pacific “Ring of Fire” is the most geologically unstable region on the planet. That is its significance, and that is a situation that will exist as long as the Earth exists.