Why in the news?
- Taiwan was struck by its most powerful earthquake in at least 25 years.
- Its susceptibility to earthquakes is attributed to its location along the Pacific “Ring of Fire” where a majority of the world’s seismic activity occurs.
- Taiwan is primarily influenced by the collision of the Philippine Sea Plate and the Eurasian Plate.
What is the Pacific ‘Ring of Fire’?
- The Pacific ‘Ring of Fire’ or Pacific Rim, or the Circum-Pacific Belt, is an area along the Pacific Ocean that is characterized by active volcanoes and frequent earthquakes.
- Volcanic arcs and oceanic trenches partly encircling the Pacific Basin form the so-called Ring of Fire.
- It is home to about 75 per cent of the world’s volcanoes – more than 450 volcanoes.
- Also, about 90 per cent of the world’s earthquakes occur here.
Its spread
- Its length is over 40,000 kilometres and traces from New Zealand clockwise in an almost circular arc covering Tonga, Kermadec Islands, Indonesia.
- It is moving up to the Philippines, Japan, and stretching eastward to the Aleutian Islands, then southward along the western coast of North America and South America.
Seismic activity of the region
- The area is along several tectonic plates including the Pacific plate, Philippine Plate, Juan de Fuca plate, Cocos plate, Nazca plate, and North American plate.
- The movement of these plates or tectonic activity makes the area witness abundant earthquakes and tsunamis every year.
- Along much of the Ring, tectonic plates move towards each other creating subduction zones.
- One plate gets pushed down or is subducted by the other plate.
- This is a very slow process – a movement of just one or two inches per year.
- As this subduction happens, rocks melt, become magma and move to Earth’s surface and cause volcanic activity.
PYQ:2020: Discuss the geophysical characteristics of Circum-Pacific Zone. |
