Final answer:
The formation of a tsunami due to an earthquake involves the locking of a megathrust, causing stress and bulging of the seafloor. When the megathrust ruptures, this leads to the displacement of water and the formation of a tsunami that can travel rapidly across the ocean and cause massive destruction when it hits coastal areas.
Step-by-step explanation:
Formation of a Tsunami due to an Earthquake
The order of events leading to the formation of a tsunami due to an earthquake is as follows:
- Megathrust is locked, causing the seafloor to bulge under stress.
- Megathrust ruptures, and bulging plate changes shape.
- Water above the plate lifts up toward the surface, forming a ridge of higher water.
- A tsunami radiates away from the disturbance; not noticeable in the open ocean.
- Tsunami approaches shore; energy concentrates in shallows to create a higher wave.
These events occur due to the tectonic plate movements under the ocean. When two plates are locked together, stress builds up in the rock. An earthquake occurs when this stress is released, causing the seafloor to displace and the water above to be lifted, thereby generating a tsunami.
Tsunamis have devastating effects on coastal regions, as demonstrated by historical events such as the 2004 Indian Ocean tsunami and the 2011 tsunami off the east coast of Japan. The speed at which a tsunami can travel in the open ocean and the energy it can release upon reaching the coast makes it a very dangerous natural phenomenon.