Which of the following statements about volcanoes are correct?
- 1. The strength of a volcano is measured by the Volcanic Explosive Index.
- 2. Iceland and Philippines were created by volcanic activity.
- 3. Volcanic soils are rich, deep and fertile and allow intensive agriculture to take place.
Select the correct answer using the code given below.
1 and 2 only
2 and 3 only
1 and 3 only
1, 2 and 3
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CDS-1 – 2023
1. The strength of a volcano is measured by the Volcanic Explosive Index: The Volcanic Explosivity Index (VEI) is a scale used to measure the relative explosiveness of volcanic eruptions. It is based on factors like the volume of erupted material, height of the eruption column, and duration of the eruption. This statement is correct.
2. Iceland and Philippines were created by volcanic activity: Iceland is situated on the Mid-Atlantic Ridge, a divergent plate boundary where volcanic activity is frequent, leading to the formation and growth of the island. The Philippines is located in the Pacific Ring of Fire, an area characterized by intense seismic and volcanic activity due to plate tectonics, and its islands are largely volcanic in origin. This statement is correct.
3. Volcanic soils are rich, deep and fertile and allow intensive agriculture to take place: Soils derived from volcanic ash and lava (Andisols) are generally known for their high fertility due to the presence of minerals and nutrients. They are not always “deep,” as depth depends on the age of the soil and the accumulation of organic matter, but their fertility allows for very productive and intensive agriculture in many volcanic regions around the world (e.g., Indonesia, Japan, parts of Italy, Central America). The statement, while potentially slightly overgeneralizing depth, is fundamentally correct regarding the fertility and agricultural potential of volcanic soils. This statement is considered correct in this context.
Since all three statements are correct, the correct option is D.
– Iceland and the Philippines are products of volcanic processes.
– Volcanic soils are typically fertile and support agriculture.
– Despite the hazards, volcanic areas attract human settlement due to fertile soils, geothermal energy potential, and mineral deposits.