The 1950 Great Assam Earthquake: Lessons in Tectonics, Disasters, and Future Vulnerability
UPSC Relevance
Prelims: Indian Geography (Plate Tectonics, The Himalayas, Earthquakes, Rivers), Disaster Management.
Mains:
GS Paper 1: Salient features of world’s physical geography; Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies).
GS Paper 3: Disaster and disaster management.
Key Highlights from the News
Main Event: The Great Assam Earthquake on August 15, 1950, which shook India's northeastern region and neighboring countries.
Intensity of Tremor: Recorded at 8.6 magnitude on the Richter scale, it was the strongest earthquake ever recorded on land.
Geological Cause: The earthquake occurred at the eastern end of the Himalayas, at the boundary where the Indian Plate and Eurasian Plate collide. This area is known as the Eastern Himalayan Syntaxis (EHS).
Unusual Movement: Unlike typical Himalayan earthquakes which primarily involve a thrusting motion, this earthquake also had a strike-slip motion.
Consequences:
Caused widespread damage and loss of life.
Landslides triggered by the earthquake blocked rivers (including the Brahmaputra), and these blockages later burst, leading to devastating flash floods.
Scientific Importance: Studies of this earthquake greatly contributed to the development of the plate tectonics theory.
Future Threat: India's northeastern region, especially the Central Himalayas, are areas prone to large earthquakes in the future. Due to increasing urbanization and construction activities, India is more vulnerable today than it was in 1950.
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