mukeshkumar007
January 2nd, 2005, 02:50 PM
if any one who want to know something about tsunami then he should read it. i have read it from a news paper.
What is a tsunami?
A tsunami (pronounced tsoo-nah-mee) is a wave train, or series of waves, generated in a body of water by an impulsive disturbance that vertically displaces the water column. Earthquakes, landslides, volcanic eruptions, explosions, and even the impact of cosmic bodies, such as meteorites, can generate tsunamis. Tsunamis can savagely attack coastlines, causing devastating property damage and loss of life.
What does "tsunami" mean?
Tsunami is a Japanese word with the English translation, "harbor wave." Represented by two characters, the top character, "tsu," means harbor, while the bottom character, "nami," means "wave." In the past, tsunamis were sometimes referred to as "tidal waves" by the general public, and as "seismic sea waves" by the scientific community. The term "tidal wave" is a misnomer; although a tsunami's impact upon a coastline is dependent upon the tidal level at the time a tsunami strikes, tsunamis are unrelated to the tides. Tides result from the imbalanced, extraterrestrial, gravitational influences of the moon, sun, and planets. The term "seismic sea wave" is also misleading. "Seismic" implies an earthquake-related generation mechanism, but a tsunami can also be caused by a nonseismic event, such as a landslide or meteorite impact.
How do tsunamis differ from other water waves?
Tsunamis are unlike wind-generated waves, which many of us may have observed on a local lake or at a coastal beach, in that they are characterized as shallow-water waves, with long periods and wave lengths. The wind-generated swell one sees at a California beach, for example, spawned by a storm out in the Pacific and rhythmically rolling in, one wave after another, might have a period of about 10 seconds and a wave length of 150 m. A tsunami, on the other hand, can have a wavelength in excess of 100 km and period on the order of one hour.
As a result of their long wave lengths, tsunamis behave as shallow-water waves. A wave becomes a shallow-water wave when the ratio between the water depth and its wave length gets very small. Shallow-water waves move at a speed that is equal to the square root of the product of the acceleration of gravity (9.8 m/s/s) and the water depth - let's see what this implies: In the Pacific Ocean, where the typical water depth is about 4000 m, a tsunami travels at about 200 m/s, or over 700 km/hr. Because the rate at which a wave loses its energy is inversely related to its wave length, tsunamis not only propagate at high speeds, they can also travel great, transoceanic distances with limited energy losses.
How do earthquakes generate tsunamis?
Tsunamis can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associated with the earth's crustal deformation; when these earthquakes occur beneath the sea, the water above the deformed area is displaced from its equilibrium position. Waves are formed as the displaced water mass, which acts under the influence of gravity, attempts to regain its equilibrium. When large areas of the sea floor elevate or subside, a tsunami can be created.
Large vertical movements of the earth's crust can occur at plate boundaries. Plates interact along these boundaries called faults. Around the margins of the Pacific Ocean, for example, denser oceanic plates slip under continental plates in a process known as subduction. Subduction earthquakes are particularly effective in generating tsunamis.
Wildlife can sense natural calamity
Wild Life has once again perplexed scientific community by their uncanny ability to SENSE TSUNAMI. Animal behavior scientists are foxed by the meager loss of animal wealth while huge loss of humans was reported from all islands. Deputy Director of Srilanka Wildlife Department Ratnayake has said that while the giant waves rushed three kilometers deep which took toll of 24000 people of the Island, Jumbos ran to safety.
Dogs, Elephants,Birds,Snakes and Leopards. They all have what the man doesn’t. The inbuilt disaster warning system. Behavior Experts are unable to explain this SIXTH SENSE or Premonition but it happens when ever a calamity occurs. In Lathur in September,1993 pet dogs barked and howled endlessly at day-break before the tremors shook the people awake. It happened in supercyclone of Orissa in October 1999 and again during quake in Bhuj & Kutch of Gujarat on Republic Day in 2001. Restless behaviour of animals is reported across the world during total solar eclipses too. African Wildlife expert Clive Walker says that wild animals pickup impending disaster much ahead of time. In the wake of Tsunami, it is time we train humans to understand animals which may be giving feelers about impending calamity.
Great Tsunamis
1929 Grand Banks, Canada
1946 Aleutian Islands, Alaska
1952 Kamchatka Peninsula, Russia
1957 Aleutian Islands, Alaska
1960 Chile
1964 Prince Williams Sound, Alaska
1975 Hawaii
Recent Tsunami events
1994 Mindoro
1994 Kuril
1994 East Java
1993 Hokkaido
1992 Flores
1992 Nicaragua
1996 Peru
1998 Papua New Guinea:
What is a tsunami?
A tsunami (pronounced tsoo-nah-mee) is a wave train, or series of waves, generated in a body of water by an impulsive disturbance that vertically displaces the water column. Earthquakes, landslides, volcanic eruptions, explosions, and even the impact of cosmic bodies, such as meteorites, can generate tsunamis. Tsunamis can savagely attack coastlines, causing devastating property damage and loss of life.
What does "tsunami" mean?
Tsunami is a Japanese word with the English translation, "harbor wave." Represented by two characters, the top character, "tsu," means harbor, while the bottom character, "nami," means "wave." In the past, tsunamis were sometimes referred to as "tidal waves" by the general public, and as "seismic sea waves" by the scientific community. The term "tidal wave" is a misnomer; although a tsunami's impact upon a coastline is dependent upon the tidal level at the time a tsunami strikes, tsunamis are unrelated to the tides. Tides result from the imbalanced, extraterrestrial, gravitational influences of the moon, sun, and planets. The term "seismic sea wave" is also misleading. "Seismic" implies an earthquake-related generation mechanism, but a tsunami can also be caused by a nonseismic event, such as a landslide or meteorite impact.
How do tsunamis differ from other water waves?
Tsunamis are unlike wind-generated waves, which many of us may have observed on a local lake or at a coastal beach, in that they are characterized as shallow-water waves, with long periods and wave lengths. The wind-generated swell one sees at a California beach, for example, spawned by a storm out in the Pacific and rhythmically rolling in, one wave after another, might have a period of about 10 seconds and a wave length of 150 m. A tsunami, on the other hand, can have a wavelength in excess of 100 km and period on the order of one hour.
As a result of their long wave lengths, tsunamis behave as shallow-water waves. A wave becomes a shallow-water wave when the ratio between the water depth and its wave length gets very small. Shallow-water waves move at a speed that is equal to the square root of the product of the acceleration of gravity (9.8 m/s/s) and the water depth - let's see what this implies: In the Pacific Ocean, where the typical water depth is about 4000 m, a tsunami travels at about 200 m/s, or over 700 km/hr. Because the rate at which a wave loses its energy is inversely related to its wave length, tsunamis not only propagate at high speeds, they can also travel great, transoceanic distances with limited energy losses.
How do earthquakes generate tsunamis?
Tsunamis can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associated with the earth's crustal deformation; when these earthquakes occur beneath the sea, the water above the deformed area is displaced from its equilibrium position. Waves are formed as the displaced water mass, which acts under the influence of gravity, attempts to regain its equilibrium. When large areas of the sea floor elevate or subside, a tsunami can be created.
Large vertical movements of the earth's crust can occur at plate boundaries. Plates interact along these boundaries called faults. Around the margins of the Pacific Ocean, for example, denser oceanic plates slip under continental plates in a process known as subduction. Subduction earthquakes are particularly effective in generating tsunamis.
Wildlife can sense natural calamity
Wild Life has once again perplexed scientific community by their uncanny ability to SENSE TSUNAMI. Animal behavior scientists are foxed by the meager loss of animal wealth while huge loss of humans was reported from all islands. Deputy Director of Srilanka Wildlife Department Ratnayake has said that while the giant waves rushed three kilometers deep which took toll of 24000 people of the Island, Jumbos ran to safety.
Dogs, Elephants,Birds,Snakes and Leopards. They all have what the man doesn’t. The inbuilt disaster warning system. Behavior Experts are unable to explain this SIXTH SENSE or Premonition but it happens when ever a calamity occurs. In Lathur in September,1993 pet dogs barked and howled endlessly at day-break before the tremors shook the people awake. It happened in supercyclone of Orissa in October 1999 and again during quake in Bhuj & Kutch of Gujarat on Republic Day in 2001. Restless behaviour of animals is reported across the world during total solar eclipses too. African Wildlife expert Clive Walker says that wild animals pickup impending disaster much ahead of time. In the wake of Tsunami, it is time we train humans to understand animals which may be giving feelers about impending calamity.
Great Tsunamis
1929 Grand Banks, Canada
1946 Aleutian Islands, Alaska
1952 Kamchatka Peninsula, Russia
1957 Aleutian Islands, Alaska
1960 Chile
1964 Prince Williams Sound, Alaska
1975 Hawaii
Recent Tsunami events
1994 Mindoro
1994 Kuril
1994 East Java
1993 Hokkaido
1992 Flores
1992 Nicaragua
1996 Peru
1998 Papua New Guinea: