Since the establishment of plate tectonics theory, many scholars have established a global volcanic model on the basis of plate theory, they believe that most volcanoes are distributed on the plate boundaries and a few in the plates, the former constitutes four major volcanic belts, namely, the Circum-Pacific Volcanic Belt, the Mid-Ocean Ridge Volcanic Belt, the East African Rift Volcanic Belt and the Alpine-Himalayan Volcanic Belt. Countries with more volcanoes include Japan, Indonesia, Italy, New Zealand and the Americas. About 60% of the world's volcanoes are around the Pacific Ocean (Figure. 3-6).
Figure 3-6 Distribution Map of Global Active Volcanoes
Circum-Pacific Volcanic Belt
The Circum-Pacific volcanic belt, also known as the Circum-Pacific Ring of Fire, begins in the Cordillera Mountains of South America and turns to the Aleutian Islands and the Kamchatka Peninsula in the northwest, extends to the Thousand Islands to the southwest,, the Japanese Islands, the Ryukyu Islands, Taiwan Islands, the Philippines Islands and the Indonesian Islands, with a total length of more than 40,000 km, annular tectonic system with an orientation to the south. There are 512 active volcanoes, of which there are more than 30 active volcanoes in the southern part of the Andes of the Lidiera Mountains in South America, 16 active volcanoes in the northern part, Yueyako volcano in the middle part with the altitude of 6723m, which is the highest active volcano in the world. The Aconcagua volcano in the Argentine Andes (6940m above sea level) is the highest extinct volcano in the world. Further north to the Caribbean, along the Pacific coast, there are famous volcanoes such as Chiriqui, Irazu, Santa Ana and Tahumurico volcanoes. North America has more than 90 active volcanoes, the famous are Mount Saint Helens, Larsen, Rainier, Shasta, Hood and Sanford volcanoes.
Volcanic activities are frequent in the Pacific rim, according to historical records, 80% of the world's modern volcanoes erupt here, mainly in North America, Kamchatka peninsula, Japan, Philippines and Indonesia. Indonesia is known as the "Country of volcanoes", in the south, including the island arc-trench zone composed of Sumatra, Java and other islands, with nearly 400 volcanoes, 129 of them are active volcanoes, in addition, submarine volcanic eruptions occur frequently, resulting in the emergence of some new volcanic islands. The volcanoes here are mostly centralized eruptions, and the intensity of volcanic eruptions is relatively large, if they occur in densely populated areas, will often cause serious volcanic disasters.
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