Q. Consider the following statements regarding the global geographic distribution of volcanoes:
1.The Pacific Ring of Fire contains the highest concentration of active subaerial volcanoes globally, directly affecting littoral nations like Japan, the Philippines, Chile, and the USA.
2.The Mid-Atlantic Ridge is characterized by explosive volcanism fueled by the subduction of the South American plate beneath the African plate.
3.Iceland experiences vigorous volcanic activity because it is situated directly over a divergent plate boundary where the North American and Eurasian plates rift apart.
Which of the statements given above are correct?
Answer: B
Notes:
Explanation:
- Statement 1 is correct: The Pacific Ring of Fire is an extensive, horseshoe-shaped seismically active belt driven by subduction zones. It accounts for roughly 75% of the world’s active and dormant volcanoes.
- Statement 2 is incorrect: The Mid-Atlantic Ridge is a divergent plate boundary where plates pull away from each other, not a subduction zone. Its volcanism is typically effusive and non-explosive, generating new basaltic oceanic crust.
- Statement 3 is correct: Iceland is a unique geological hotspot located directly atop the subaerial portion of the Mid-Atlantic Ridge. The rifting between the North American plate moving west and the Eurasian plate moving east creates a major crustal expansion zone filled by rising mantle magma.
