Surface-Wave Magnitude “Surface-Wave Magnitude” is the magnitude of an earthquake that scientists estimate using measurements of the amplitude of surface waves.

Gap-Graded The term “Gap-Graded” is used by geologists, engineers, and soil scientists in the geotechnical engineering field to describe the gradation of a soil sample, specifically when some particle sizes are missing. Aside from being “gap graded,” a soil sample can be described as “well-graded” (also referred to as poorly sorted), or “poorly graded” (or…

Wing Dam or Wing Dike A “Wing Dam” or “Wing Dike” refers to a dam that intentionally retains a fraction of the width of a flowing water source. Unlike a conventional dam, a wind dam aims to divert the path of water flow. Additionally, a wing dike can control the velocity of water flow. For…

Rigidity Definition Rigidity – In geotechnical engineering and engineering geology, rigidity represents the ratio of the shear stress and the amount of angular rotation that it produces, within a rock sample.

Twinning Definition Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.