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Pacific Tsunami Alert
Tsunami warnings issued across the Pacific after 8.8 M quake in Russia’s Kamchatka Peninsula
Context: A massive 8.8 magnitude earthquake struck off Russia’s Kamchatka Peninsula on July 30, 2025, triggering tsunami warnings across the Pacific Ocean, including Japan, Hawaii, Alaska, and the U.S. West Coast.
What Are Tsunamis and How Do They Occur?
- A tsunami is a series of ocean waves caused by the sudden displacement of a large volume of water, typically due to seismic activity beneath the ocean floor.
- Tsunamis are not tidal waves: Unlike tides caused by gravitational forces, tsunamis are caused by geophysical forces.
- Causes:
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- Undersea Earthquakes: Most tsunamis (approximately 80%) are triggered by earthquakes at subduction zones, where tectonic plates collide and one plate slips beneath the other.
- The 2004 Indian Ocean tsunami, triggered by a 9.1-magnitude earthquake, killed over 230,000 people across 14 countries.
- Volcanic Eruptions: Explosive eruptions or collapsing volcanic islands can displace water rapidly.
- Landslides: Either underwater or coastal landslides can push water outward, generating waves.
- Meteorite Impacts: Rare but catastrophic, a large meteor hitting the ocean could trigger massive tsunamis.
- Undersea Earthquakes: Most tsunamis (approximately 80%) are triggered by earthquakes at subduction zones, where tectonic plates collide and one plate slips beneath the other.
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Key Characteristics:
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- In deep ocean, tsunami waves travel at jetliner speeds (up to 800 km/h) but have low height, making them hard to detect.
- As they approach shore, the waves slow down and grow taller, sometimes reaching heights of 30 meters or more.
- Tsunamis can strike repeatedly over hours or even days, and may sweep inland for kilometres, causing massive destruction.
Why Are Natural Disasters Increasing?
According to the World Meteorological Organisation, disaster events have increased fivefold over the last 50 years. The frequency and intensity of natural disasters have surged due to a combination of climatic, environmental, and human factors.
- Climate Change: Earth’s average temperature has increased by about 1.1°C since the late 1800s, intensifying weather extremes. Warmer oceans fuel stronger cyclones and erratic rainfall, as confirmed by IPCC reports.
- Urbanisation & Development: Expansion into high-risk zones (coastal areas, floodplains, fault lines). Deforestation and poor land-use practices increase vulnerability to floods and landslides.
- Ring of Fire Connection: Kamchatka lies on the Pacific Ring of Fire, a seismic hotspot responsible for 90% of earthquakes and 75% of active volcanoes.
- Environmental Degradation: Loss of wetlands, forests, and natural buffers reduces resilience against disasters. Soil erosion and reduced biodiversity make ecosystems more fragile.
What measures can be taken to deter such natural disasters?
- Early Warning Systems: Global systems like PTWC and IOTWS monitor seismic and ocean activity, supported by DART buoys that detect undersea pressure changes to confirm tsunamis. Real-time alerts are issued via sirens, mobile apps, and emergency broadcasts for timely public warning.
- Land Use and Urban Planning: Disaster risk is reduced by relocating vulnerable communities to higher ground, enforcing zoning laws to limit coastal construction, and establishing evacuation routes with solar-powered signage for reliable guidance during emergencies.
- Infrastructure and Engineering Solutions: Tsunami-prone countries like Japan use vertical evacuation shelters and automated sea gates for rapid protection. Coastal defences such as seawalls (as developed in Kerala), breakwaters, and elevated roads further reduce wave impact and safeguard communities.
- Natural Defences: Nature-based solutions like mangrove forests and coastal vegetation help absorb wave energy, while dune restoration and beach nourishment reduce coastal erosion and enhance shoreline stability.
- Policy and Governance: India’s NDMA leads disaster planning and response, aligning with the UN’s Sendai Framework to enhance resilience through global cooperation. Legal frameworks ensure the enforcement of building codes, land use rules, and emergency protocols for effective risk reduction.
