Search results
Results From The WOW.Com Content Network
An earthquake's hypocenter or focus is the position where the strain energy stored in the rock is first released, marking the point where the fault begins to rupture. [3] This occurs directly beneath the epicenter, at a distance known as the hypocentral depth or focal depth. [3]
Dip is defined as the angle of the fault relative to the surface of the earth, which indicates the plane on which slip will occur. Lastly, in any non-vertical fault, the block above the fault is called the hanging wall, while the blockbelow the fault is called the footwall. [4] Normal and reverse dip-slip faults with labeled hanging wall and ...
San Andreas Fault System (Banning fault, Mission Creek fault, South Pass fault, San Jacinto fault, Elsinore fault) 1300: California, United States: Dextral strike-slip: Active: 1906 San Francisco (M7.7 to 8.25), 1989 Loma Prieta (M6.9) San Ramón Fault: Chile: Thrust fault: Sawtooth Fault: Idaho, United States: Normal fault: Seattle Fault ...
The Seattle Fault was first recognized as a significant seismic hazard in 1992, when a set of reports showed that about 1,100 years ago it was the scene of a major earthquake of about magnitude 7 – an event that entered Native American oral traditions. Extensive research has since shown the Seattle Fault to be part of a regional system of faults.
The fault rupture begins at the focus and then expands along the fault surface. The rupture stops where the stresses become insufficient to continue breaking the fault (because the rocks are stronger) or where the rupture enters ductile material. [8] The magnitude of an earthquake is related to the total area of its fault rupture. [8]
An explosive or implosive mechanism produces an isotropic seismic source. Slip on a planar fault surface results in a double-couple source. Uniform outward motion in a single plane due to normal shortening is known as a compensated linear vector dipole source. [3] Deep-focus earthquakes have been shown to contain a combination of these sources.
A simulation of a plausible major southern San Andreas fault earthquake — a magnitude 7.8 that begins near the Mexican border along the fault plane and unzips all the way to L.A. County's ...
A fault plane is the plane that represents the fracture surface of a fault. A fault trace or fault line is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. [3] [4] A fault zone is a cluster of parallel faults.