Changes

Earthquakes (and other earth movements) produce different types of [[seismic wave]]s.  These waves travel through the earth (soil and rock), and provide an effective way to "image" or "see" events and structures in the Earth's subsurface.

Earthquakes (and other earth movements) produce different types of [[seismic wave]]s.  These waves travel through the earth (soil and rock), and provide an effective way to "image" or "see" events and structures in the Earth's subsurface.

One of the earliest important discoveries was that the outer core of the Earth is molten.  Pressure waves pass through the core. If the core was not in a liquified state, ransverse or shear waves that shake side-to-side would be recorded as they respond to the presence of rigid material.

One of the earliest important discoveries was that the outer core of the Earth is molten.  Pressure waves pass through the core. If the core was not in a liquefied state, ransverse or shear waves that shake side-to-side would be recorded as they respond to the presence of rigid material.

The process of mapping subsurface features is a specialty field called [[seismography]] or [[seismic interpretation]].  Seismic waves are generated in controlled experiments using dynamite and other explosives which generated waves withing the earth. These waves are convolved to yield seismic data which have been used (successfully) to map geological features in hydrocarbon-bearing rocks, faults (cracks in deep rock), rock types, and a lot of other features in the earth.

The process of mapping subsurface features is a specialty field called [[seismography]] or [[seismic interpretation]].  Seismic waves are generated in controlled experiments using dynamite and other explosives which generated waves withing the earth. These waves are convolved to yield seismic data which have been used (successfully) to map geological features in hydrocarbon-bearing rocks, faults (cracks in deep rock), rock types, and a lot of other features in the earth.