Waves are formed by any disturbance upon a fluid medium. 2. Surface ocean waves are formed by wind stress. If the wind is weak, capillary waves form. Their restoring force is capillarity (caused by the hydrogen bonds between water molecules). If the wind is stronger, gravity waves form. Their restoring force is gravity. 3. Tsunamis are formed as a result of undersea disturbances. These can be tectonic movements, like earthquakes, but they can also be caused by landslides, as in the one that occurred in Anchorage, Alaska.
Tsunamis are barely noticable in the open ocean, but their wave steepness and wave speed increase tremendously as they approach shore.
An earthquake generates a series of seismic waves that travel through the interior or near the surface of the Earth.
There are four types of seismic waves. How will three identically engineered buildings react to an earthquake on different types of substrate? The first set of waves to be detected by seismographs are P waves, or primary waves, as theyБre the fastest. TheyБre compressional or longitudinal waves that push and pull the ground in the direction the wave is traveling. They usually cause very little damage.
S waves, or secondary waves, come next since they travel more slowly than P waves. They travel in the same direction, but they shake the ground back and forth perpendicular to the direction the wave is traveling. S waves are more dangerous than P waves because they have greater amplitude and produce vertical and horizontal motion of the ground surface.