MPPSC 2021 Prelims Paper-I · Question 46 of 100

Correct — B, Circum-Pacific belt. Often called the 'Ring of Fire,' this horseshoe-shaped zone rings the Pacific Ocean along near-continuous subduction zones (the Andes, Central America, the Cascades, the Aleutians, Kamchatka, Japan, the Philippines, Indonesia, New Zealand) and hosts roughly three-quarters of the world's active volcanoes, along with the great majority of its earthquakes.

• (a)Mid Continental — This is the Mid-Continental (Alpide) belt — running from Java through the Himalayas to the Mediterranean — the world's second most active seismic-volcanic zone, but well behind the Circum-Pacific belt in eruption count.
• (c)Mid-Atlantic belt — Marks the Mid-Atlantic Ridge, a divergent (constructive) plate boundary with volcanism concentrated at spreading centres such as Iceland — active, but far less numerous than the subduction-driven Circum-Pacific belt.
• (d)Intraplate volcanic belt — Refers to scattered hotspot volcanism far from plate boundaries (e.g., Hawaii) — a minority of the world's volcanoes and not a continuous belt at all.

Most of Earth's volcanoes cluster along plate boundaries rather than occurring randomly. Convergent boundaries, where an oceanic plate subducts beneath another plate, generate the most frequent and often most explosive volcanism — and the Pacific Ocean's rim is ringed almost continuously by exactly this kind of boundary, which is why it dominates global eruption counts.

Physical geography textbooks classify the world's seismic-volcanic zones into three belts: the Circum-Pacific belt (most active), the Mid-Continental/Alpide belt (second most active, Java–Himalaya–Mediterranean), and the Mid-Atlantic belt (a constructive-boundary ridge). The trap is picking the Mid-Continental belt because it sounds central/major, when the Circum-Pacific belt is actually the busiest.

• Circum-Pacific belt = 'Ring of Fire' — about three-quarters of the world's active volcanoes
• Formed mainly by subduction of oceanic plates around the Pacific rim
• Also responsible for the large majority of the world's earthquakes
• Second most active zone: the Mid-Continental (Alpide) belt, from Java through the Himalayas to the Mediterranean

• Confusing the Mid-Atlantic belt (a divergent boundary) with the Circum-Pacific belt (a convergent/subduction zone)
• Assuming 'intraplate' volcanoes form a continuous belt — they are scattered hotspots, not a belt

Usually a direct 'which belt has the most X' recall question, or a map-based identify-the-belt item; MPPSC/UPSC also probe the Ring of Fire via 'which countries lie on it' or 'why do Japan/Indonesia have frequent earthquakes' framings.

No directly related past PYQ was found.

• practice — not a real PYQ

  The 'Ring of Fire' is another name for which volcanic-seismic belt?

  • (a)Circum-Pacific belt
  • (b)Mid-Atlantic belt
  • (c)Alpide belt
  • (d)African Rift belt

  Answer(a) Circum-Pacific belt — it encircles the Pacific Ocean along a near-continuous chain of subduction zones.

• practice — not a real PYQ

  The Circum-Pacific belt's intense volcanic and seismic activity is associated mainly with which type of plate boundary?

  • (a)Divergent boundary
  • (b)Convergent (subduction) boundary
  • (c)Transform boundary
  • (d)Passive continental margin

  Answer(b) Convergent (subduction) boundary — oceanic plates diving beneath neighbouring plates generate the belt's volcanism and earthquakes.