Pacific Ring of Fire ( UPSC Prelims)

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News Context

An 8.8 magnitude earthquake impacted Russia's Kamchatka Peninsula, a region within the seismically active Pacific Ring of Fire. This event, possibly caused by shallow reverse faulting, generated tsunami waves that affected the shores of both Russia and Japan.

About Reverse Faulting

 ● Reverse faulting (also known as thrust faulting) happens when a section of the Earth's crust is forced upward over another section as a result of compressional forces.  
  ● "Shallow" Reverse faulting indicates that the rupture took place close to the Earth's surface.  
        ○ This can lead to intense ground shaking, significant aftershocks, tsunamis, and destruction of infrastructure.

Pacific Ring of Fire

Circum-Pacific Belt, also known as the Pacific Ring of Fire, is a horseshoe-shaped region encircling the Pacific Ocean. It is notable for its high concentration of both active and dormant volcanoes and frequent earthquakes. This area is responsible for approximately 75% of the world's active volcanoes and about 90% of the world's earthquakes.
 Reasons for the Formation of the Pacific Ring of Fire:
  ● Plate Tectonics:  
    ● Convergent plate boundaries between the Pacific Plate and other plates such as the Indo-Australian Plate and Juan de Fuca Plate create subduction zones, which lead to volcanic activity.  
    ● Divergent Boundaries result in seafloor spreading and the formation of rift valleys. An example is the East Pacific Rise, where the Pacific Plate diverges from the Cocos, Nazca, and Antarctic Plates, leading to volcanism and the presence of hydrothermal vents.  
      ○ The Earth's deepest ocean trenches, such as the Mariana Trench, are found along these subduction zones, causing deep earthquakes.
        ○ Earthquakes occur along the trenches and faults as the plates scrape against each other. An example is the transform boundary at the San Andreas Fault in California.