steady as she goes! meaning, steady as she goes! definition | English Cobuild dictionary. steady. 1 adj A steady situation continues or develops gradually without any interruptions and is not likely to change quickly. Despite the steady progress of building work, the campaign against it is still going strong...
Seismic waves are divided into two types: Body waves and surface waves. Body waves include P and S waves, and these are the two types of waves that are used to determine the internal structure of the Earth. (There are other types of seismic waves, but they relate to surface damage and only travel through the Earth s crust, not the entire Earth. If you are interested though, there is a short activity to show you what they are and how they move.
Seismic waves are elastic waves that propagate in solid or fluid materials. They can be divided into body waves that travel through the interior of the materials; surface waves that travel along surfaces or interfaces between materials; and normal modes, a form of standing wave. Body waves. There are two types of body waves, Pressure waves or Primary waves and Shear or Secondary waves . P-waves are longitudinal waves that involve compression and expansion in the direction that the wave is moving and are always the first waves to appear on a seismogram as they are the fastest moving waves through solids.