The Origin of the Ring of Fire
What is the Ring of Fire?
The Ring of Fire is over 40,200 km (25,000 miles) long chain of tectonic activity, including earthquakes, volcanoes, mountains, islands, and natural disasters. That activity is sometimes devastating for the region. However, it also played a key part in creating it. It is home to the world’s deepest trench- the Mariana Trench (11 km or over 7 miles under sea level). The earthquakes happen due to the tension created when the plates move sideways past one another. In the places where plates are subducted (one moves under another), geological structures like mountains and trenches appear. When the rock is subducted, it turns to magma, and that causes volcanic activity.
The Tectonic Activity
The Earth’s tectonic plates lay on lava, and because of that, they aren’t stable. The Ring of Fire is a unique place, where many of them meet and interact with each other. In America, the Cocos Plate and the Nazca Plate are subducted by the South American Plate. Moreover, the first one is also subducted by the Caribbean Plate. The North American Plate subducts the Pacific, which is also subducted to the south in Japan. In southwest Asia, smaller plates interact with each other and the Pacific Plate, creating a complex system. The collisions and subduction of plates cause 90% of earthquakes globally. They also change the geology of every region within their reach.
Geography of the Region
The Andes and their volcanic belt formed due to the subduction of the Nazca and Antarctic Plates under the South American Plate. There are four major volcanic zones, separated by volcanism-free gaps. The Northern Volcanic Zone extends from Colombia to Ecuador. The Central goes through Peru and Chile, and the Southern through central Chile. Finally, the Austral Volcanic Zone goes through Patagonia. Besides volcanic activity, the region is full of geothermal activity with its hot springs and geysers. It could be a source of clean energy; however, it’s not used now.
The North American part of the Ring of Fire goes through the American Cordillera. There is a 900km volcanic activity belt in central-southern Mexico, called the Trans-Mexican Volcanic Belt. The Cascadia subduction zone is home to 20 major volcanoes in the US. It also produces earthquakes with a magnitude of 9 or even higher! The most recently active region is Alaska, Mount Redoubt erupted in 2009. It also holds the record for the world’s second-largest earthquake. In Canada, tectonic activity appears in various areas, including British Columbia, Yukon, and Vancouver. Many unique volcanic forms, including tuyas, can be found nearby Canadian volcanoes.
About 10% of the world’s volcanoes are in Japan, and 1500 earthquakes are recorded each year. That phenomenon appears due to the Pacific Plate’s subduction and the Philippian Sea Plate. The largest recorded earthquake in the country (and 5th in the world) happened in March 2011; it was a 9 magnitude earthquake. Other natural disasters, including tsunamis, volcanic eruptions, cyclones, are frequent. In Indonesia and the Philippines, the world’s most active volcanoes are responsible for many catastrophes and a dozen of thousands of deaths. Finally, the Russian Kamchatka Peninsula is also a very active region, with 160 volcanoes, 29 active.
Oceania, and Antarctica
The North Island of New Zealand is home to many active, youthful volcanoes. Earthquakes appear quite frequently due to interaction between the Indo-Australian and Pacific plates. Wellington, the country’s capital, is within the highest-risk zone. Finally, the Ring of Fire is completed by Antarctica in the south. There are many volcanoes due to the Antarctic Plate’s interaction with the surrounding structures.
Major Observations within the Ring of Fire
In the second half of the 19th-century, scientists first concluded that the Japanese Islands lay in a ‘circle’ that went through Pacific shores. Today we know it is the most tectonically active region in the world. 81% of major earthquakes appear within the Ring of Fire. There is also a lot of volcanic activity; 22 of the 25 largest eruptions appeared in the last 11,700 years. California’s transform fault (a border between the Pacific and North American plates), called the San Andreas Fault, generates a dozen micro-earthquakes every day. However, there are too weak, and humans don’t feel them. Another fault, the Queen Charlotte Fault, is in British Columbia, and in 1949 it generated Canada’s largest recorded earthquake, magnitude 8.1.