Extreme Science: The San Andreas Fault
How California is predicting and preparing for the inevitable
Watch The Earth Open And Close During Japan’s 2011 Earthquake
Over 18,000 people were killed by a magnitude 9.0 earthquake and subsequent tsunami that struck Northeastern Japan on March 11, 2011. The earthquake lasted six minutes, and had over 250 aftershocks. A...
Epicenter
The epicenter, epicentre /ˈɛpɪsɛntər/ or epicentrum is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originate...
Epicenter - Wikipedia
P-wave
P-waves are a type of body wave that is the first wave to arrive at the seismograph, called seismic waves in seismology, that can travel through a continuum. The continuum is made up of gases (as soun...
P-wave - Wikipedia
Extreme Science: The San Andreas Fault
How California is predicting and preparing for the inevitable
Watch The Earth Open And Close During Japan’s 2011 Earthquake
Over 18,000 people were killed by a magnitude 9.0 earthquake and subsequent tsunami that struck Northeastern Japan on March 11, 2011. The earthquake lasted six minutes, and had over 250 aftershocks. A...
Aftershock
An aftershock is a smaller earthquake that occurs after a previous large earthquake, in the same area of the main shock. If an aftershock is larger than the main shock, the aftershock is redesignated ...
Aftershock - Wikipedia
Surface wave
In physics, a surface wave is a mechanical wave that propagates along the interface between differing media, usually as a gravity wave between two fluids with different densities. A surface wave can ...
Surface wave - Wikipedia
Seismic wave
Seismic waves are waves of energy that travel through the Earth's layers, and are a result of an earthquake, explosion, or a volcano that gives out low-frequency acoustic energy. Many other natural an...
Seismic wave - Wikipedia
S-wave
A type of elastic wave, the S-wave, secondary wave, or shear wave (sometimes called an elastic S-wave) is one of the two main types of elastic body waves, so named because they move through the body o...
S-wave - Wikipedia
Glacial earthquake
Glacial earthquakes are earthquakes as large as magnitude 5.1 that occur in glaciated areas where the glacier moves faster than one kilometer per year.The number of glacial earthquakes in Greenland sh...
Glacial earthquake - Wikipedia
Lake breakout
Lake breakout is a geological term that refers to the collapse of a (usually high-altitude) lake. High-altitude lakes tend to form in volcanic craters – where they are called crater lakes –...
Coal mine bump
A coal mine bump (also called a bump, a mine bump, or a mountain bump) is a seismic jolt occurring within a mine, often due to the explosive collapse of a wall or one or more support pillars, sometime...
Harmonic tremor
Harmonic tremor describes a long-duration release of seismic energy, with distinct spectral (harmonic) lines, that often precedes or accompanies a volcanic eruption. More generally, a volcanic tremor ...
Harmonic tremor - Wikipedia
Thrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. The...
Thrust fault - Wikipedia
Aseismic creep
In geology, aseismic creep is measurable surface displacement along a fault in the absence of notable earthquakes. An example is along the Calaveras fault in Hollister, California. Streets crossing th...
Aseismic creep - Wikipedia
Cryoseism
A cryoseism, also known as an ice quake or a frost quake, may be caused by a sudden cracking action in frozen soil or rock saturated with water or ice. As water drains into ground, it may eventually f...
Cryoseism - Wikipedia
Receiver function
A receiver function technique is a way to model the structure of the Earth by using the information from teleseismic earthquakes recorded at a three component seismograph.A teleseismic P-wave will gen...
Love wave
In elastodynamics, Love waves, named after Augustus Edward Hough Love, are horizontally polarized surface waves. The Love wave is a result of the interference of many shear waves (S–waves) guided by ...
Love wave - Wikipedia
Sand geyser
A Sand Geyser or Sand Fountain is a geologic phenomena which occurs in association with earthquakes and other seismic events. In the geologic record, these are seen as clastic dikes.
Sand geyser - Wikipedia
Tsunami earthquake
A tsunami earthquake triggers a tsunami of a magnitude that is very much larger than the magnitude of the earthquake as measured by shorter-period seismic waves. The term was introduced by Hiroo Kanam...
Slow earthquake
A slow earthquake is a discontinuous, earthquake-like event that releases energy over a period of hours to months, rather than the seconds to minutes characteristic of a typical earthquake. First dete...
Slow earthquake - Wikipedia
Remotely triggered earthquakes
It is postulated that large earthquakes can have an influence outside of the immediate aftershock zone, and remotely trigger earthquakes at considerable distance. The further one gets from the initia...
Remotely triggered earthquakes - Wikipedia
Brittle–ductile transition zone
The brittle-ductile transition zone is the strongest part of the Earth's crust. For quartz and feldspar rich rocks in continental crust this occurs at an approximate depth of 13–18 km (roughly e...
Brittle–ductile transition zone - Wikipedia
Infrasound
Infrasound, sometimes referred to as low-frequency sound, is sound that is lower in frequency than 20 Hz (hertz) or cycles per second, the "normal" limit of human hearing. Hearing becomes gradual...
Infrasound - Wikipedia
Peak ground acceleration
Peak ground acceleration (PGA) is a measure of earthquake acceleration on the ground and an important input parameter for earthquake engineering, also known as the design basis earthquake ground motio...
Meizoseismal area
The meizoseismal area in an earthquake is the area of maximum damage. For example, in the Charleston, South Carolina, earthquake of 1886, the meizoseismal area was an area about twenty by thirty miles...
Induced seismicity
Induced seismicity refers to typically minor earthquakes and tremors that are caused by human activity that alters the stresses and strains on the Earth's crust. Most induced seismicity is of a low ma...
Shutter ridge
A shutter ridge is a ridge which has moved along a fault line, blocking or diverting drainage. Typically, a shutter ridge creates a valley corresponding to the alignment of the fault that produces it...