Kamchatka quake highlights dangers along Pacific Ring

Source: The post Kamchatka quake highlights dangers along Pacific Ring has been created, based on the article “The Kamchatka quake” published in “Indian Express” on 31st July 2025

UPSC Syllabus Topic: GS Paper 1- Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity.

Context: A massive 8.8 magnitude earthquake hit Russia’s Kamchatka Peninsula, triggering a tsunami across the northern Pacific. Though flooding and damage were reported in multiple countries, no casualties occurred. The event has renewed focus on the seismic vulnerability of this region and similar global zones.

The Kamchatka Earthquake and Tsunami Impact

1. Scale and Location: The earthquake, one of the strongest globally, struck about 6,500 km east of Moscow. It was the most powerful since Japan’s 2011 quake.
2. Tsunami Reach and Effects: The quake triggered a tsunami, causing waves of 3–4 metres in Kamchatka, about five feet in Hawaii, and two feet in Japan. Several places reported flooding and structural damage.
3. Lack of Casualties: Despite its magnitude, no lives were lost, unlike the 2011 Japan event that led to a nuclear disaster at Fukushima.

Ring of Fire and Seismic Patterns

1. Location in Seismic Belt: Kamchatka lies in the Circum-Pacific Belt, or Ring of Fire, the world’s most seismically active zone, encircling the Pacific.
2. Widespread Coverage: This belt includes nations such as Russia, Japan, Indonesia, Chile, the U.S., and New Zealand, across both sides of the Pacific.
3. High Earthquake Concentration: The Ring of Fire accounts for over 80% of the largest earthquakes. All 23 quakes of magnitude 8+ in the past 20 years occurred here.
4. Active Kamchatka-Japan Stretch: From Kamchatka to northern Japan, including the Kuril Islands, over 130 quakes of 7+ magnitude have occurred since 1900. A 9.0 quake was recorded here in 1952.

Subduction as the Earthquake Trigger

1. Basic Mechanism: Earthquakes originate from subduction, where a denser tectonic plate slides beneath a lighter one, building stress that is eventually released.
2. Land vs Oceanic Subduction: While most subduction zones lie under oceans, some, like the Himalayas, occur over land. These zones are highly prone to earthquakes.
3. Pacific Plate’s Influence: The dense Pacific Plate is subducting under several continental plates, making the Ring of Fire extremely active.
4. Expert Perspective: Geologist Vineet Gehlot highlights that nowhere else on Earth are so many subduction zones active, explaining the frequency of strong quakes here.

Comparison with Other Seismic Belts

1. Alpide Belt Characteristics: The Alpide belt, running from Indonesia to Turkey, contributes about 15–17% of major quakes. It cuts through densely populated areas, making its quakes more deadly.
2. Impact of Population Density: The Kamchatka quake caused no deaths due to a low population density (0.62/sq km). In contrast, Nepal’s 7.6 quake in 2015 killed over 15,000 people.
3. Mid-Atlantic Ridge: This underwater ridge runs through the Atlantic. It produces moderate quakes, but their distance from land limits their impact.
4. Upper Limit of Earthquake Strength: A 9.5 magnitude quake is near the maximum possible. A magnitude 10 would require a faultline spanning nearly the entire Earth—which doesn’t exist.

Question for practice:

Discuss how subduction zones contribute to the occurrence of powerful earthquakes, with reference to the Kamchatka region and the Ring of Fire.