Two-thirds of the worlds volcanoes are located in the Circum-Pacific r...
- The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. Roughly 90% of all earthquakes occur along the Ring of Fire, and the ring is dotted with 75% of all active volcanoes on Earth.
- The Ring of Fire isn’t quite a circular ring. It is shaped more like a 40,000-kilometer (25,000-mile) horseshoe. The Ring of Fire is the result of plate tectonics. Most tectonic activity in the Ring of Fire occurs in these geologically active zones.
- A convergent plate boundary is formed by tectonic plates crashing into each other. Convergent boundaries are often subduction zones, where the heavier plate slips under the lighter plate, creating a deep trench. This subduction changes the dense mantle material into buoyant magma, which rises through the crust to the Earth’s surface.
- Over millions of years, the rising magma creates a series of active volcanoes known as a volcanic arc. These arcs create both islands and continental mountain ranges. Both geographic features continue to form as the Pacific Plate subducts beneath the North American Plate. Hence statement 1 is correct.
- The Andes Mountains include the world’s highest active volcano, Nevados Ojos del Salado, as the Nazca Plate subducts beneath the South American Plate.
- Most of the active volcanoes on The Ring of Fire are found on its western edge, from the Kamchatka Peninsula in Russia, through the islands of Japan and Southeast Asia, to New Zealand, where the dense Pacific Plate is subducting beneath the Indo-Australian Plate. Hence statement 3 is correct.
- The East Pacific Rise is a site of major seafloor spreading in the Ring of Fire. The East Pacific Rise is located on the divergent boundary of the Pacific Plate and the Cocos Plate (west of Central America), the Nazca Plate (west of South America), and the Antarctic Plate. In addition to volcanic activity, the rise also has a number of hydrothermal vents. Hence statement 2 is correct.
- The San Andreas Fault, stretching along the central west coast of North America, is one of the most active faults on the Ring of Fire. It lies on the transform boundary between the North American Plate, which is moving south, and the Pacific Plate, which is moving north. Volcanoes do not typically occur at transform boundaries. One of the reasons for this is that there is little or no magma available at the plate boundary
Two-thirds of the worlds volcanoes are located in the Circum-Pacific r...
Introduction:
The Circum-Pacific region, also known as the Pacific Ring of Fire, is a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur. Two-thirds of the world's volcanoes are located in this region. There are several reasons behind this concentration of volcanoes in the Circum-Pacific region.
Reasons behind the concentration of volcanoes in the Circum-Pacific region:
1. Subduction of Pacific Plate beneath the North American Plate:
- The Pacific Plate is subducting beneath the North American Plate along the western coast of North America, resulting in the formation of the Cascade Range and the Aleutian Islands.
- The subduction zone creates ideal conditions for the formation of volcanoes. As the Pacific Plate sinks beneath the North American Plate, it undergoes melting due to the increase in temperature and pressure. This melted material, known as magma, rises to the surface and erupts, forming volcanoes.
2. Divergent boundary of the Pacific Plate and the Cocos Plate:
- The Pacific Plate and the Cocos Plate meet along the western coast of Central and South America, creating a divergent boundary.
- At this boundary, the two plates are moving away from each other, causing the formation of a rift zone. Magma rises to fill the gap created by the separating plates, leading to volcanic activity.
- This process has resulted in the formation of volcanoes such as the Andes Mountains and the Central American Volcanic Belt.
3. Subduction of Pacific Plate beneath the Indo-Australian Plate:
- The Pacific Plate is also subducting beneath the Indo-Australian Plate in the western Pacific region, giving rise to the formation of volcanoes.
- This subduction zone is responsible for the formation of the Pacific Ring of Fire, which is known for its high volcanic and seismic activity.
- Volcanic arcs such as the Philippines, Japan, and Indonesia are a result of the subduction of the Pacific Plate beneath the Indo-Australian Plate.
Conclusion:
The concentration of volcanoes in the Circum-Pacific region can be attributed to the subduction of the Pacific Plate beneath various neighboring plates, such as the North American Plate and the Indo-Australian Plate. Additionally, the divergent boundary between the Pacific Plate and the Cocos Plate also contributes to volcanic activity in this region. These geological processes create ideal conditions for the formation of volcanoes, making the Circum-Pacific region a hotbed of volcanic activity.
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