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EARTHQUAKE CASE STUDY : 1897 ASSAM EARTHQUAKE Date – 12 th June 1897 Origin Time – 17:11 IST Epicenter – 14 kilometres ESE of Sangsik (Meghalaya), India Latitude: 25.50o N Longitude: 91.00o E Magnitude: Ms 8.7

Assam Earthquake

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Assam Earthquake Details

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Earthquake Case Study : 1897 Assam Earthquake Date 12th June 1897 Origin Time 17:11 IST Epicenter 14 kilometres ESE of Sangsik (Meghalaya), India Latitude: 25.50o NLongitude: 91.00o E Magnitude: Ms 8.7

IntroductionNortheastern Region, including Assam is prone to natural disasters like earthquake, floods, landslides, cyclone and occasional draught.

Earthquake Occurrences :-

Wedge between two plate collision boundaries, the Himalayan in the north and the Indo-burman in the east, the Northeastern region is one of the seismically most active regions of the world.

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Complex tectonic and geology set up of the region and intense continental convergence of the northward moving Indian plate at the rate of approx 20mm/year can produce earthquakes of magnitudes 8 and above every few hundred years. The two great earthquakes of magnitudes 8.7 in 1897 and 1950 are memorable events in the history of the World.

Continued.These earthquakes have been so intense that the rivers changed their courses, ground elevations immensely affected.Besides as many as twenty destructive earthquakes of magnitudes 6~7 rocked this region during the past century.

Plateau Pop-up during the 1897 Assam earthquake The Shillong plateau is not being built as part of a system of thin-skinned thrusting, but is bounded by a high-angle reverse fault to its north, and probably also to its south.1) North - Oldham Fault2) South - Dauki Fault The Shillong plateau thus resembles the 'pop-up' structures that border thrust belts elsewhere.

Plateau Pop-up during the 1897 Assam earthquake

Severity of EarthquakeEarthquake originated on a south-south-west dipping fault, named the Oldham Fault, bounding the north-western section of the Shillong Plateau within the INDIAN PALTE. During the event, the total slip on this fault, amounted to 16 metres, which is among the greatest for any known earthquake.

ContinuedGeodetic observations indicate that the rupture extended up to 35 kilometers into the crust and might have even cut though its base, which in this region, lies at a depth of 43-46 kilometers. The rupture of the Oldham Fault terminated at a depth of 9 kilometers from the surface of the earth, implying that this event was blind.

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Area shaken by the 1897 Assam Earthquake

Damages CausedConsidering the size of the earthquake, the mortality rate was not that high, but property damage was very heavy.About1542 people were killed and hundreds more injured. Caused great destruction to many towns in Assam and Meghalaya. Most often referred to is Shillong and Guwahati & Near by towns, where most of the structures like the Telegraph House, bridges, churches,monuments were demolished.

Continued.Landslides were reported all across the Garo Hills.The earthquake badly affected both Dhaka and Kolkata, where most of the buildings were heavily damaged and many collapsed.Shaking effects were experienced over a wide area of the subcontinent as far as Himachal Pradesh, Myanmar.Extended Upto In South - Bezwada (Andhra Pradesh)West Sehore & Khandwa (Madhya Pradesh)There were very many aftershocks

SHOCKING TRAGEDY

WILLANS MEMORIAL SHILLONG GIRLs SCHOOL SHILLONG

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The McCabe's bungalow before and after the earthquake

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Ruins of Governments House

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All Saints Church

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SHILLONG BAZAAR

Thank you.!!! - Jitendra Joshi