Sand Boil
A “Sand Boil” is a cone-shaped deposit of sand that is formed during an earthquake. A Sand Boil occurs when subsurface sand layers liquefy and are then blown to the surface through cracks.
A “Sand Boil” is a cone-shaped deposit of sand that is formed during an earthquake. A Sand Boil occurs when subsurface sand layers liquefy and are then blown to the surface through cracks.

What is a Concrete Gravity Dam? A Concrete Gravity Dam is also known as “Gravity Arch Dam,” and is a freshwater-retaining concrete structure that has a wider footing (base) than the top-section. The purpose of a Concrete Gravity Dam is to maintain a low center of gravity, in order to avoid collapsing in the event…

Vapor Intrusion Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.

Hydraulic Conductivity (K) “Hydraulic Conductivity” (K), in hydrogeology and hydrology, represents the capacity of a porous medium (such as soil) to transmit water, as per Darcy’s Law. To illustrate, the rate at which fluid can move through a permeable medium (such as soil), depends on the properties of that soil (such as intrinsic permeability) and…

Body-Wave Magnitude Body-Wave Magnitude: A method for determining earthquake size from the amplitude of body waves. The body-wave magnitude focuses on P-waves and S-waves, which travel faster through the Earth’s crust and mantle.

Lithosphere Lithosphere: The lithosphere comprises the Earth’s crust as well as part of the upper mantle. In fact, the lithosphere is approximately 100 kilometers thick and is relatively strong as compared to the underlying asthenosphere.

Type Section Geologic Definition In geology, the term “type section” refers to a specific stratigraphic unit, that can be compared to other parts of the geologic unit. For a type section, it’s preferred to describe the location where the geologic unit has the maximum thickness, and where the top and bottom units are observable.