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TSUNAMI GENERAL PARAMETERS

TSUNAMI GENERAL PARAMETERS. WHAT IS TSUNAMI?. A tsunami is a series of ocean waves of extremely long wave length and long period generated in a body of water by an impulsive disturbance that displaces the water. CAUSES OF TSUNAMI. Impulses are: Submarine Earthquakes Undersea Landslides

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TSUNAMI GENERAL PARAMETERS

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  1. TSUNAMI GENERAL PARAMETERS

  2. WHAT IS TSUNAMI? • Atsunamiis a series of ocean waves ofextremely long wave lengthandlong periodgenerated in a body of water byan impulsive disturbancethat displaces the water.

  3. CAUSES OF TSUNAMI • Impulses are: • Submarine Earthquakes • Undersea Landslides • Volcanoes • Impacts of objects from outer space (such as meteorites, asteroids, and comets)

  4. TSUNAMI • Tsunamis are shallow-water waves. • Wind-generated waves : • Period : 5 to 20 seconds • Wavelength : 100 to 200 meters (300 to 600 ft). • A tsunami: • Period: in the range of 10 minutes to 2 hrs • Wavelength: in excess of 300 miles (500 km).

  5. SHALLOW WATER WAVES • A wave is characterized as a shallow-water wave when the ratio between the water depth and its wavelength gets very small. • The speed of a shallow-water wave is equal to the square root of the product of the acceleration of gravity (32ft/sec/sec or 980cm/sec/sec) and the depth of the water. • The rate at which a wave loses its energy is inversely related to its wavelength. • It is because of their long wavelengths that tsunamis behave as It is because of their long wavelengths that tsunamis behave as shallow-water waves.

  6. TSUNAMI • Since a tsunami has a very large wave length, it will lose little energy as it propagates. Hence in very deep water, a tsunami will travel at high speeds and travel great transoceanic distances with limited energy loss. • For example, when the ocean is 20,000 feet (6100 m) deep, unnoticed tsunami travel about 550 miles per hour (890 km/hr), the speed of a jet airplane. And they can move from one side of the Pacific Ocean to the other side in less than one day

  7. Tsunamis generation: • Initiation • Split • Amplification • Run-up

  8. Tsunamis generation: • Initiation

  9. Tsunamis generation: II. Split

  10. Tsunamis generation: III. Amplification

  11. Tsunamis generation: IV. Run-up

  12. The runup phenomena is one of the important subject for coastal development in coastal engineering. The hazard of long waves generated by earthquakes have in many cases causes deaths and extensive destructions near the coastal regions. On this basis many studies on long wave runup phenomena have been presented numerically and analytically.

  13. INTRODUCTION Different from wind generated waves, the length of long waves are longer comparing to water depth. Wind waves show orbital motion, on the other hand long waves show translatory motion. It losses very little energy while it is propagating in deep water. The velocity is directly proportional to the square root of the depth times grvitational acceleration. C = √(g d)

  14. As the water depth decreases, the speed of the long wave starts to decrease. However the change of the total energy remains constant. Therefore while the speed is decreasing, the wave height grows enormously.

  15. 2.3.1The Storegga Slide The Storegga slide is : 1. one of the largest landslides in the world at Storegga 2. occurred around 8100 years ago, 100 kilometres north west of the Møre coast. 3. ended up at a depth of 300-2500 metres, created a 10-20 meter high wave that reached the Norwegian coast. • The mass slid around 800 kilometres into the deep sea, and its back edge is around 300 kilometres long.

  16. 2.3.1The Storegga Slide Figure 2.2. CHALLENGING: The Ormen Lange field is located close to the steep back edge of the Storegga slide, which 8100 years ago ended up at a depth of 300-2500 metres. http://www.ormenlange.com/en/about_ormen/key_features/storegga_slide/

  17. 2.3.1The Storegga Slide

  18. 2.3.1The Storegga Slide Figure 2.2. CHALLENGING: The Ormen Lange field is located close to the steep back edge of the Storegga slide, which 8100 years ago ended up at a depth of 300-2500 metres. http://www.ormenlange.com/en/about_ormen/key_features/storegga_slide/

  19. 2.3.1The Storegga Slide • There were three slide events • Storegga 1(30,000-35,000 years before present) 1. It is involved 69% of the total sediments moved by the three slidescombined. 2. Jansen (1987) reported that this event probably affected thewhole area of the slide scar. 3.The slide surface is smoother than that of the second event, thisindicates that the slide was shallow and only affected the uppersediments 4. The thickness for the slide deposit is estimated to be in the order of130-200m. 

  20. 2.3.1The Storegga slide • Storegga 2(approximately 7,000 years before present) 1.It occurred within the first slide scar cutting back 8 km into the continental shelf. 2.The second slide cut deeper into the seafloor than the first slide, this is reflected by the slide surface morphology, which is rough and blocky. 3. The second slide had the longest run out of the three slides. Slide deposits have been found as far as the Aegir ridge some 800km from the slide headwall.This represents a water depth interval of 3500m from the headwall to the end of the slide runout .

  21. 2.3.1The Storegga slide • Storegga 3(approximately 7,000 years before present) 1.The third Storegga slide had its headwall at 1,000m water depth. 2.The slide itself was confined to the shallower areas of the first and second slide scars .The slide can be traced down to depths of 1500 1600m with possible extensions down to the Gloria valley.

  22. 2.3.2The Santorini /(Thera) Eruption and Tsunami Minoan Age in Aegean Sea. • One of the main centers of explosive eruptions is located on Thera (Santorini), and the eruption of the Thera volcano in late Minoan time (1600–1300 B.C.) is considered to have been the most significant Aegean explosive volcanism during the late Holocene.

  23. 2.3.2The Santorini /(Thera) Eruption and Tsunami Minoan Age in Aegean Sea. • The last eruptive phase of Thera resulted in an enormous submarine caldera, which is believed to have produced tsunamis on a large scale.Some evidences were found however, the cause of the tsunami and its effects on the area have not been well understood. • On the Aegean Sea coast of western Turkey (Didim and Fethiye) and Crete (Gouves), the traces were found of tsunami deposits related to the Thera eruption. The sedimentological consequences and the hydraulics of a Theracaused tsunami indicate that the eruption of Thera volcano was earlier than the previous estimates and the tsunami did not have disruptive influence on Minoan civilization. (Minoura et. al., 2000)

  24. Santorini Middle East Technical University, Civil Engineering Dept., Ocean Engineering Research Center, Ankara TURKEY Int. Symp. on Tsunami Disaster Mitigation in Future, Kobe, Japan, Jan. 2005

  25. Figure 2.3: Map of Aegean Sea and adjacent region showing areas and sites mentioned in text. Felsic volcanic products of Minoan eruption are found on Aegean Sea coasts and in eastern Mediterranean deep-sea cores. Tsunamigenic sediment layers were discovered in Didim and Fethye (western Turkey) and Gouves (Crete) (Minoura et. al., 2000)

  26. Middle East Technical University, Civil Engineering Dept., Ocean Engineering Research Center, Ankara TURKEY

  27. Middle East Technical University, Civil Engineering Dept., Ocean Engineering Research Center, Ankara TURKEY

  28. Prof. Costas Synolakis, Civil Eng. Sallim Pamukcu, USC,USA Assoc. Prof. Dr. Ahmet C Yalciner, METU-Turkey Middle East Technical University, Civil Engineering Dept., Ocean Engineering Research Center, Ankara TURKEY

  29. Prof. Costas Synolakis, Civil Eng. Sallim Pamukcu, USC,USA Assoc. Prof. Dr. Ahmet C Yalciner, METU-Turkey Middle East Technical University, Civil Engineering Dept., Ocean Engineering Research Center, Ankara TURKEY

  30. 2.4.1 PACIFIC OCEAN EARTQUKAES and TSUNAMIS i) April 1, 1946 Aleutian Earthquake and Tsunami: Magnitude: 7.8. Wave Height: 3.5 m Affected Places: Near Unimak Island in Alaska's Aleutian Island Chain, Hawaiian( waves reached five hours later) Death Toll: 165 Loss of Property is $26 (in 1946 dollars). • In 1948, and as a result of this tsunami, the U.S. established a million PacificTsunami Warning Center in Hawaii.

  31. 2.4.1 PACIFIC OCEAN EARTHQUKAES and TSUNAMIS ii)May 2 , 1960 Chilean Earthquake andTsunami Magnitude: 9.5 (The largest earthquake of the 20th century) Affected Places:The coast of south central Chile Death Toll: 2,300 people in Chile. (There was tremendous loss of life and property in the Hawaiian Islands, in Japan and elsewhere in the Pacific. ) 61 people in Hilo, Hawaii, Loss of Property is more than $500 million (1960 dollars).

  32. 2.4.1 PACIFIC OCEAN EARTHQUKAES and TSUNAMIS iii)October 4, 1994, Russia- Kuril Islands Shikotan Earthquake and Tsunami Magnitude: 8.1 Wave Height: 10 m Affected Places: The islands of the Pacific nation of Vanuatu Death Toll: 11 people Loss of Property is extremely extensive

  33. 2.4.1PACIFIC OCEAN EARTHQUKAES and TSUNAMIS iv)June 23, 2001 Peru-Southern Earthquake and Tsunami Magnitude: 8.4 Wave Height: 3-4.5 m Affected Places: North of town of Ocona in Southern Peru Death Toll: 96 people Loss of Property is extremely extensive

  34. 2.4.2INDIAN OCEAN EARTHQUAKES AND TSUNAMIS i) December 12, 1992 Indonesia – Flores Island Earthquake and Tsunami Magnitude: 7.7 Wave Height: 26.2 m (Riang-Kroka); 2-5.2 m (Flores Island); Affected Places: The islands of the Pacific nation of Vanuatu Death Toll: 690 people Loss of Property is extremely extensive

  35. 2.4.2INDIAN OCEAN EARTHQUAKES AND TSUNAMIS ii)December 26 , 2004 Indian Ocean Eartquake and Tsunami Magnitude: 9 to 9.3 Wave Height: 6 m Affected Places: from Indonesia in the east, to The coast of Africa, some 7,000km (4,000 miles) away Dead Toll: 310,000 people Loss of Property is extremely extensive

  36. 2.4.3THE CARIBBEAN TSUNAMIS The Carribean sea is 1. one of the biggest marginal seas in the planet 2. located in lattitudes 7oN and 23oN, longitudes -88 o E and -60 o E. 3. bordered on the N and Eby the WIndies archipelago,on the Sby SAmerica mainland, and on the W by the American isthmus. 3. linked tothe Gulf of Mexicoby theYucatán Channel; tothe Atlantic by many straits, of whichtheWindward Channel and Mona Passage are themost important;and tothe Pacific Ocean by thePanama Canal.

  37. 2.4.3MEDITERRANEAN TSUNAMIS The Mediterranean sea is 1.one of the biggest marginal seas in the planet 2.located in lattitudes 30 o N and 47 oN, and longitudes -5 oE and 43 oW. 3.bordered on the N and W by Europe, on the south byAfrica, on the East by Asia. Siciliy Dividesthe sea to easternand western basins. There is asingle connection with theocean: the strait ofGibraltar. The other connection withthe Red sea isSuez Canal.

  38. Table 2.2: The tsunami events occured in the Caribbean sea with their probable epicenters and affected areas (Lander et. al. 2002)

  39. Table 2.3: The list of tsunamis that occured in the vicinity of Anatolia since 1630 B.C. (Doumas, 1980a,b, Hardy and Renfrew 1990a,b,c, Altınok et. al., 2001, Papadopulos,2001)

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