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Tsunami ppt
This document summarizes the findings of an impact survey conducted along the Tamil Nadu coast that was affected by the 2004 Indian Ocean tsunami. Key findings include: - The Nagapattinam to Point Calimere sector experienced the highest loss of life and damage due to dense populations and low-lying topography. It was classified as the most vulnerable zone. - The Ramanathapuram to Tuticorin sector had less impact as it was protected by offshore islands and coral reefs that dissipated wave energy. Most areas were classified as safe. - The Tuticorin to Tiruchendur sector also experienced limited damage due to protection from the Tambraparni River estuary and
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Tsunami ppt
- 1. TSUNAMI MITIGATIONTSUNAMI MITIGATION ANDMANAGEMENTAND MANAGEMENT By- o ( )
- 2. PART-IPART-I NITTY GRITTY OFTSUNAMI
- 3. TSUNAMI BASICSTSUNAMI BASICS •Term Tsunami a Japanese word means Port Wave • Defined as a Wave Train generated by the impulsive disturbances of a water body caused by displacement due to: • Sea quake • Volcanic eruption • Landslide/subsidence in the ocean
- 4. WAVE CHARACTERISTCSWAVE CHARACTERISTCS Parametersgovern size and occurrence: • Fault Mechanism • Depth of Focus • Proximity of source of Earthquake
- 5. FAULT MECHANISMFAULT MECHANISM •Mega earthquakes (M>8) associated both vertical and horizontal movements • Net displacement-movement in both components • Huge displacement of water is essential • Vertical movements likely to generate more Tsunamis • Strike slip can cause Ts lesser magnitude
- 6. OTHER PARAMETERSOTHER PARAMETERS •Depth of Focus: • Shallow for large magnitude EQ – Large Tsunami • Tsunamigenic source may be near field or far field • Near field < 2500 km • Far field > 2500 km • Normally mega Eqs associated with Megathrust events,occurring where one tectonic plate subducts beneath another.
- 7. WAVE DYNAMICSWAVE DYNAMICS •Ts energy flux based on wave speed and height • Ts speed diminishes in shallow water but height grows up • In open sea wavelength very large with low amplitude • Closer to shore it is reverse • Kinetic energy of waves transformed in potential energy near the shore • Velocity can reach upto 800km/hr • Ts is governed by shallow water wave dynamics • Ocean floor configuration and bathymetry controls and modifies its propagation characteristics • Ts not only propagate at high speeds but also can travel great distance with limited energy loss
- 8. WAVE DYNAMICSWAVE DYNAMICS •When waves of Ts approach land their appearance and behaviour dependent on several factors • Important being topography of the sea floor and shape of the shoreline • Wave hts increased in bays, river mouth, lagoons and creeks • Off-shore coral reef can dissipate the energy
- 9. TSUNAMI PARAMETRESTSUNAMI PARAMETRES •Following parameters required to assess the impact of Tsunami: • Tsunami magnitude (Tm) :Estimated or calculated Tm =log.H (run up in m.) • Wave Height : Actual ht of Ts recorded by tidal gauge • Run up(H) : Maximum vertical ht. on land Ts reached above msl • Tide State : Run up ht. during high tide> and less during low tide
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- 11. INDIAN OCEAN TSUNAMIINDIANOCEAN TSUNAMI 2626thth December,2004December,2004 • On the morning of 26th Dec.2004,eastern hemisphere was struck a major natural catastrophe, Tsunami • Shell shocked everyone with a palm of gloom with unprecedented destruction in vast areas of India and adjoining SE Asian countries
- 12. EARTHQUAKE AND TSUNAMIEARTHQUAKEAND TSUNAMI EPISODEEPISODE • A shallow EQ of M 9+ stuck the coast off Sumatra at around 30km on 26th De,2004 at around 0630hrs • Epicentre located 260km SSE of Banda Aceh,Indonesia • Major EQ was followed by a number of after shocks • EQ triggered the Tsunami • Unleashed vast devastation all along the littoral countries fringing Indian Ocean • More than 1.5lakh people lost lives and property worth millions lost and several thousands rendered homeless
- 13. EARTHQUAKE AND TSUNAMIEARTHQUAKEAND TSUNAMI EPISODEEPISODE • Tsunami stuck different stretches at different timings mainly based on distance from the epicentral location • Ts recorded in Andaman Nicobar islands at around 0725hrs • Chennai coast at around 0845hrs • Nagapattinam coast at around 0900hrs • Kanyakumari coast at around 1230hrs • Tuticorin at around 1330 hrs • West coast at Kayamkulam at around 1230hrs.
- 14. FINDINGS OF DISCOVERYFINDINGSOF DISCOVERY CHANNEL SURVEYCHANNEL SURVEY • Study proved it as a mega thrust faulting at the epicentre- a large scale rupturing and vertical displacement which generated the Tsunami • Indian plate moving at the rate of 5cm every year subducted deep under the Burma plate • Continuous subduction of Indian plate built up enormous stress on Burma plate • At breaking point accumulated stress released in the form EQ
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- 17. IMPACT SURVEY-IMPACT SURVEY-THEAREATHE AREA • Coastline between Nagapattinam and Kanyakumari, Tamil Nadu,South India, fringing the east coast (480 km) Sectors • Nagapattinam – Point Calimere (57 km) • Point Calimere – Ramanathapuram (190 km) • Ramanathapuram – Rameswaram – Tuticorin (113 km) • Tuticorin – Tiruchendur (35 Km) • Tiruchendur – Kanyakumari(85 km)
- 18. IMPACT SURVEY-IMPACT SURVEY- OBJECTIVESOBJECTIVES PostTsunami Impact Assessment • Measurement of Run-up elevation and run-up length • Soil • Ground water • Geothermal springs • Corals and marine life • Monuments and temples • Social life • Classification of zones depending on severity of impacts both to loss of lives and damage to property Formulation of Disaster Management Plan(DMP)
- 19. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) • A 57 km N-S coastal stretch lying to the south of Karaikal • Coastline consists of 10- 30m wide sandy beach, 1.5 to 3.0 km wide recent dune complex • Two to three dune ridges of 3-5 m height run along the coast and coalesce to form compound dune complex
- 20. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector(I)Nagapattinam-Point Calimere Sector(I) • A huge loss of life and property reported in this sector • 6000+ people have simply been washed away.
- 21. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) • Closely berthed boats in the fishing jetty- Nagapattinam, collided due to the tsunami waves • Many lifted and perched over the bridge • Some thrown inside the adjoining fisherman colony
- 22. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) • Flattening of beach • Heavy siltation (tsunami deposit) in Vettar, Uppanar and Vellar rivers
- 23. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) • Loss of life and damage to property comparatively less between Velanganni and Point Calimere • Due to the presence of linear/wide barrier sand dunes along the coast, wide beach and thick belt of plantations near Pattanavarnattam and Point Calimere sanctuary.
- 24. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) • The tsunami wave arrived by 09: 20 hrs • Hit the coast at an acute angle • Wave splash on hitting the coast rose up to 8-10m. • Post- tsunami survey indicates run-up elevation from 2 to 3m • Run-up length varied from 0.2 to 1.25 km depending on the coastal geomorphologyRun up length
- 25. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector(I)Nagapattinam-Point Calimere Sector(I) • Maximum inundation by seawater of the order of 0.5 to 1.2 km in the low-lying stretch between Pattanchcheri and Nagapattinam • Causing damage to topsoil and ground water • Shoreline appears to have transgressed a few meters inland in this segment
- 26. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) • Cause behind the major tragedy in this sector is mainly due to the dense population/inhabitations seen along coast especially between Nagore in the north and Velanganni in the south • In addition, the area falls within the low lying zone, wrapped around by the distributaries of Cauvery delta causing much sea water inundation • Lack of major geomorphic features like elevated/wide beach, distinct barrier dunes to protect against the fury of killer waves.
- 27. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) Disaster Rating • Considering heavy loss of life and property, the sector is categorized as the heavily damaged zone (Vulnerable Zone).
- 28. IMPACT SURVEYIMPACT SURVEY Nagapattinam-PointCalimere Sector (I)Nagapattinam-Point Calimere Sector (I) Disaster Rating • Considering heavy loss of life and property, the sector is categorized as the heavily damaged zone (Vulnerable Zone).
- 29. IMPACT SURVEYIMPACT SURVEY Ramanathapuram–Rameshwaram-Tuticorin Sector(III)Ramanathapuram –Rameshwaram-Tuticorin Sector(III) • Sector comprises the famous Rameswaram island and Dhanushkodi • Coastal stretch of Mandapam and Tuticorin stetching for about 85 Km
- 30. IMPACT SURVEYIMPACT SURVEY Ramanathapuram–Rameshwaram-Tuticorin Sector(III)Ramanathapuram –Rameshwaram-Tuticorin Sector(III) • The cuspate foreland of Vaigai between Uchipuli and Mandapam and the Rameswaram island lying further east, separated by the sea over a distance of 2 Km, forms the divide between the Palk Bay in the north and Gulf of Mannar in the south.
- 31. IMPACT SURVEYIMPACT SURVEY Ramanathapuram–Rameshwaram-Tuticorin Sector (III)Ramanathapuram –Rameshwaram-Tuticorin Sector (III) • Coastline exhibits discontinuously calcareous sandstone and shell limestone of Quaternary period and occurs as abrasion platforms. • Shoreline covered mostly by beach sand and oxidized ‘teri’ sand.
- 32. IMPACT SURVEYIMPACT SURVEY Ramanathapuram–Rameshwaram-Tuticorin Sector (III)Ramanathapuram –Rameshwaram-Tuticorin Sector (III) IMPACT • Coastal erosion • Variations in soil and water characteristics • Significant impacts are the widening of river mouths in Gundar, Vembar and Vaippar rivers and backflow of seawater into the river and tidal inlets • Deposition of sand and clay inside lagoon and lakes • No major effect to recent sand dune complex • Tip of Dhanushkodi shows erosion along the coast
- 33. IMPACT SURVEYIMPACT SURVEY Ramanathapuram–Rameshwaram-Tuticorin Sector (III)Ramanathapuram –Rameshwaram-Tuticorin Sector (III) Disaster Rating • Considering the marginal impact of tsunami waves, the sector may be categorised under less damaged zone(Safe) • Except for some low lying belts lying near the coast, north and south of Tuticorin town, besides the industrial belt located to the south of Tuticorin.
- 34. IMPACT SURVEYIMPACT SURVEY Ramanathapuram–Rameshwaram-Tuticorin Sector (III)Ramanathapuram –Rameshwaram-Tuticorin Sector (III) • A total of 21 small islands, with coral reef scattered in this part of the sea • Acted as natural speed breakers to diminish the energy flux of the waves.
- 35. IMPACT SURVEYIMPACT SURVEY Tuticorin-TiruchendurSector (IV)Tuticorin-Tiruchendur Sector (IV) • Sector falls within the Gulf of Mannar and extends for about 35 km along NNE-SSW and N-S directions. • Major coastal landforms include beach, recent dune complex,Tambraparni estuary, etc. • Beach is narrow with 10-15 m width except in Tambraparni estuarine delta, where it is between 15 and 25 m • Tambraparni estuarine delta, has three major tidal inlets • Dense Mangrove vegetations are seen in all these channels
- 36. IMPACT SURVEYIMPACT SURVEY Tuticorin-TiruchendurSector (IV)Tuticorin-Tiruchendur Sector (IV) Impact • No significant change in quality of ground water • Iimpact on mangrove cultivations within Tambraparni estuary and on saltpans negligible
- 37. IMPACT SURVEYIMPACT SURVEY Tuticorin-TiruchendurSector (IV)Tuticorin-Tiruchendur Sector (IV) • Post-tsunami survey in this sector documented the arrival time of the most destructive waves between 13:00 and 13:30 hrs • Run –up elevation of 1.5 to 2 m and wave splash of 3 to 6 m • Inundation (run-up length) between 25 and 500m • Withdrawal of sea during the pulses of tsunami waves was 50 –1000 m
- 38. IMPACT SURVEYIMPACT SURVEY Tuticorin-TiruchendurSector (IV)Tuticorin-Tiruchendur Sector (IV) Disaster Rating • Considering the limited damages and natural protection by Tambraparni estuary and its mangrove plantations and sparse population along the coast, the sector may be categorized under less damaged zone (Safe) • Except for the erosional fronts of Kayalpattinam and south bay of Tuticorin
- 39. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) • Extends for about 85 km • Lies in the lower segment of Gulf of Mannar, protruding into Indian Ocean. • Land forms include beaches, recent dune complex, wave cut platforms; abrasian platforms, shore platforms by quarrying, bay, etc.
- 40. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) • Withdrawal of sea both at Tiruchendur and Kanyakumari was quite conspicuous. Shoreline
- 41. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) • Villages of Kulasekarapattinam and Manappad were protected against major devastation by the wave breakers(groynes) already erected,
- 42. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) • Impact on placer deposits between Kuttam and Ovari was not significant except for enrichment of Ilmenite near Vattakkottai by the uprush of the waves and depletion of lighter fractions (garnet) by the back wash
- 43. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) • At Kanyakumari coast loose boulders were tossed by the upsurge of Tsunami waves
- 44. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) • Bore of tsunami waves at kanyakumari
- 45. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) Post-tsunami survey • Recorded a run-up elevation of waves between 1 m and 3 m • Run-up length between 10 m and 250 m • Wave splash rose maximum up to10m at Vivekananda rock memorial, Kanyakumari • Withdrawal of sea between the pulses of tsunami waves ranged from 250 to 1000m
- 46. IMPACT SURVEYIMPACT SURVEY Tiruchendur–Kanyakumari Sector (V)Tiruchendur –Kanyakumari Sector (V) Disaster Rating • Considering the damages it may be categorised under ‘marginally high’.