Unconfined Aquifer Unconfined Aquifer: In the hydrogeology branch of geology, an unconfined aquifer is an aquifer that has a water table. In fact, an unconfined aquifer can only be the uppermost hydrogeologic unit and is particularly one that has no hydraulic head (or pressure) that is equal to atmospheric pressure. To illustrate, depth to groundwater…

Stratosphere Stratosphere: The stratosphere of a terrestrial planet is the second-lowest member of the atmosphere. On Earth, the stratosphere starts atop the troposphere at approximately 10 kilometers above mean sea level, and terminates roughly 50 kilometers above mean sea level. In fact, geologists understand that the Earth’s ozone layer exists within the stratosphere, which absorbs…

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.

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

Soil Creep Definition Soil Creep is a type of landslide that entails the slow and gradual movement of a soil mass (or even some loose rock) materials.

Potentiometric Surface The term “Potentiometric Surface” means the hydrogeological surface that represents the total hydraulic head of groundwater from a confined aquifer or semi-confined aquifer that’s under pressure. The Potentiometric Surface of an aquifer is defined by the level to which water will rise in a groundwater monitoring well (that’s exclusively screened within said aquifer).