How Does an Earthquake Form a Tsunami?

 How Does an Earthquake Form a Tsunami?

Tsunamis

A tsunami occurs when a large body of water, such as an ocean or sea, experiences displacement that causes a long-wavelength wave of water to reach the shore. The most common cause of a tsunami is an underwater earthquake, but they can also be caused by other events, such as a volcano or underwater landslide. Tsunamis often occur without any warning, but monitoring stations in some areas of the world now allow scientists to issue tsunami warnings when conditions that could cause a tsunami are present.

Tectonic Earthquakes

Tectonic earthquakes are a common cause of tsunamis. They often occur in areas where two crustal plates are pushing against each other, forcing one plate to slide under the other. These earthquakes shift the crust of the earth, leading to a rapid drop or rise of sea floor. When this happens, the water directly above the shifting plate rises or falls as well, creating a wall that rises above the surrounding water. The rest of the water near it shifts to try and compensate for the sudden change. Because the area of sea floor that rises or falls is usually miles in length, the resulting water displacement also covers a large area. Larger earthquakes typically cause larger surface displacements and larger tsunamis.

Split Tsunamis

As the water tries to settle after an earthquake, the initial wall of water that originally formed splits into two waves. One travels outward across the deep ocean and the other travels toward the nearest shore. As the waves travel, they stretch out so they are not as tall, but are extremely long. They travel at the ocean surface and their speed depends on the depth of the ocean below them.

Tsunami Landing

As the tsunami comes close to a coastline, it encounters the continental slope, the place where the seafloor gradually rises up to the landmass. As it approaches land, the wavelength gets smaller and the amplitude gets larger, so it becomes taller and slower than when it was in open ocean. When it hits the shore, the wave usually causes a rapid rise of the entire coastline to far above the normal sea level.

How Does an Earthquake Form a Tsunami Video :

HOW ARE TSUNAMIS FORMED 2

HOW ARE TSUNAMIS FORMED 2 

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. A tsunami can be generated by any disturbance that displaces a large water mass from its equilibrium position. In the case of earthquake-generated tsunamis, the water column is disturbed by the uplift or subsidence of the sea floor. 

Submarine landslides, which often accompany large earthquakes, as well as collapses of volcanic edifices, can also disturb the overlying water column as sediment and rock slump downslope and are redistributed across the sea floor. Similarly, a violent submarine volcanic eruption can create an impulsive force that uplifts the water column and generates a tsunami. Conversely, supermarine landslides and cosmic-body impacts disturb the water from above, as momentum from falling debris is transferred to the water into which the debris falls. Generally speaking, tsunamis generated from these mechanisms, unlike the Pacific-wide tsunamis caused by some earthquakes, dissipate quickly and rarely affect coastlines distant from the source area. How are tsunamis formed..

. what-is-tsunami

HOW ARE TSUNAMIS FORMED VIDEO :

How Are Tsunamis Formed

HOW ARE TSUNAMIS FORMED 

 A tsunami is a series of waves generated in an ocean or other body of water by a disturbance such as an earthquake, landslide, volcanic eruption, or meteorite impact. The picture at the left shows how an earthquake can generate a tsunami in the overlying water. Undersea earthquakes, which typically occur at boundaries between Earth’s tectonic plates, cause the water above to be moved up or down. Tsunami waves are formed as the displaced water, which acts under the influence of gravity, attempts to find a stable position again. 

Undersea landslides, which can be caused by large earthquakes, can also cause tsunami waves to form as water attempts to find a stable position. Undersea volcano eruptions can create enough force to uplift the water column and generate a tsunami. Asteroid impacts disturb the water from above, as momentum from falling debris is transferred to the water into which the debris falls. How Are Tsunamis Formed... physical-characteristics-of-tsunamis

How Are Tsunamis Formed Video :