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Quake (natural phenomenon)
Encyclopedia
A quake is the result when the surface of a planet
, moon
or star
begins to shake.
Types of quakes include:
that results from the sudden release of stored energy in the Earth
's crust
that creates seismic wave
s. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground and sometimes cause tsunamis, which may lead to loss of life and destruction of property. An earthquake is caused by tectonic plates (sections of the Earth's crust) getting stuck and putting a strain on the ground. The strain becomes so great that rocks give way and fault lines occur.
). They were first discovered by the Apollo
astronaut
s. Moonquakes are much weaker than the largest earthquakes.
Information about moonquakes comes from seismometers placed on the Moon by Apollo astronauts from 1969 through 1972. The instruments placed by the Apollo 12, 14, 15 and 16 functioned perfectly until they were switched off in 1977.
According to NASA
, there are at least four different kinds of moonquakes:
The first three kinds of moonquakes mentioned above tend to be mild; however, shallow moonquakes can register up to 5.5 on the Richter scale. Between 1972 and 1977, twenty-eight shallow moonquakes were observed. On Earth, quakes of magnitude 4.5 and above can cause damage to buildings and other rigid structures.
. There is currently no explanation as to why marsquakes occur.
.
A venusquake may have caused a new scarp and a landslide to form. An image of the landslides was taken in November 1990 during the first flight around Venus by the Magellan's spacecraft. Another image was taken on July 23, 1991 as the Magellan spacecraft revolved around Venus for the second time. Each image was twenty-four kilometers (14.4 miles) across and thirty-eight kilometers (twenty-three miles) long, and was centered at two degrees south latitude and seventy-four degrees east longitude. The pair of Magellan images shows a region in Aphrodite Terra, within a steeply sloping valley that is cut by many fractures (Faults).
Seismic waves produced by sunquakes can shake the Sun to its very center, just as earthquakes can cause the entire Earth to shake. However, sunquakes involve much more energy than their terrestrial counterparts. An observed sunquake, which was produced by a perfectly ordinary solar flare
, was equivalent to an earthquake of a magnitude 11.3 on the Richter scale. That is 89,000 times more energy than the devastating 1906 San Francisco earthquake
, at a magnitude of 8 on the same scale. Scientists remain somewhat perplexed about how such a relatively modest flare could have the downward thrust and power to generate such powerful seismic waves.
phenomenon that occurs when the crust of a neutron star
undergoes a sudden adjustment, analogous to an earthquake on Earth. This is thought to be the source of the giant gamma ray
flares that are produced approximately once per decade from soft gamma repeater
s. Starquakes are thought to be caused by huge stresses exerted on the surface of the neutron star produced by twists in the ultra-strong interior magnetic fields
.
The largest recorded starquake occurred on the ultracompact stellar corpse (magnetar
) SGR 1806-20
. It released gamma rays equivalent to 1036 kW in intensity. This starquake occurred 50,000 light years away. Had the event occurred within a distance of ten light years from Earth, the event could have potentially triggered a mass extinction on Earth.
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
, moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
or star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
begins to shake.
Types of quakes include:
Earthquake
An earthquake is a phenomenonPhenomenon
A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...
that results from the sudden release of stored energy in the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's crust
Crust (geology)
In geology, the crust is the outermost solid shell of a rocky planet or natural satellite, which is chemically distinct from the underlying mantle...
that creates seismic wave
Seismic wave
Seismic waves are waves of energy that travel through the earth, and are a result of an earthquake, explosion, or a volcano that imparts low-frequency acoustic energy. Many other natural and anthropogenic sources create low amplitude waves commonly referred to as ambient vibrations. Seismic waves...
s. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground and sometimes cause tsunamis, which may lead to loss of life and destruction of property. An earthquake is caused by tectonic plates (sections of the Earth's crust) getting stuck and putting a strain on the ground. The strain becomes so great that rocks give way and fault lines occur.
Moonquake
A moonquake is the lunar equivalent of an earthquake (i.e., a quake on the MoonMoon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
). They were first discovered by the Apollo
Project Apollo
The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...
astronaut
Astronaut
An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
s. Moonquakes are much weaker than the largest earthquakes.
Information about moonquakes comes from seismometers placed on the Moon by Apollo astronauts from 1969 through 1972. The instruments placed by the Apollo 12, 14, 15 and 16 functioned perfectly until they were switched off in 1977.
According to NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
, there are at least four different kinds of moonquakes:
- Deep moonquakes (~700 km below the surface, probably tidal in origin)
- MeteoriteMeteoriteA meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
impact vibrations - Thermal moonquakes (the frigid lunar crust expands when sunlight returns after the two week lunar night)
- Shallow moonquakes (20 or 30 kilometers below the surface)
The first three kinds of moonquakes mentioned above tend to be mild; however, shallow moonquakes can register up to 5.5 on the Richter scale. Between 1972 and 1977, twenty-eight shallow moonquakes were observed. On Earth, quakes of magnitude 4.5 and above can cause damage to buildings and other rigid structures.
Marsquake
A marsquake is a quake that occurs on the planet MarsMars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
. There is currently no explanation as to why marsquakes occur.
Venusquake
A venusquake is a quake that occurs on the planet VenusVenus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
.
A venusquake may have caused a new scarp and a landslide to form. An image of the landslides was taken in November 1990 during the first flight around Venus by the Magellan's spacecraft. Another image was taken on July 23, 1991 as the Magellan spacecraft revolved around Venus for the second time. Each image was twenty-four kilometers (14.4 miles) across and thirty-eight kilometers (twenty-three miles) long, and was centered at two degrees south latitude and seventy-four degrees east longitude. The pair of Magellan images shows a region in Aphrodite Terra, within a steeply sloping valley that is cut by many fractures (Faults).
Sunquake
A sunquake is a quake that occurs on the Sun.Seismic waves produced by sunquakes can shake the Sun to its very center, just as earthquakes can cause the entire Earth to shake. However, sunquakes involve much more energy than their terrestrial counterparts. An observed sunquake, which was produced by a perfectly ordinary solar flare
Solar flare
A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy . The flare ejects clouds of electrons, ions, and atoms through the corona into space. These clouds typically reach Earth a day...
, was equivalent to an earthquake of a magnitude 11.3 on the Richter scale. That is 89,000 times more energy than the devastating 1906 San Francisco earthquake
1906 San Francisco earthquake
The San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, California, and the coast of Northern California at 5:12 a.m. on Wednesday, April 18, 1906. The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.9; however, other...
, at a magnitude of 8 on the same scale. Scientists remain somewhat perplexed about how such a relatively modest flare could have the downward thrust and power to generate such powerful seismic waves.
Starquake
A starquake is an astrophysicalAstrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...
phenomenon that occurs when the crust of a neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
undergoes a sudden adjustment, analogous to an earthquake on Earth. This is thought to be the source of the giant gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
flares that are produced approximately once per decade from soft gamma repeater
Soft gamma repeater
A soft gamma repeater is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals. It is conjectured that they are a type of magnetar or, alternatively, neutron stars with fossil disks around them....
s. Starquakes are thought to be caused by huge stresses exerted on the surface of the neutron star produced by twists in the ultra-strong interior magnetic fields
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
.
The largest recorded starquake occurred on the ultracompact stellar corpse (magnetar
Magnetar
A magnetar is a type of neutron star with an extremely powerful magnetic field, the decay of which powers the emission of copious high-energy electromagnetic radiation, particularly X-rays and gamma rays...
) SGR 1806-20
SGR 1806-20
|- style="vertical-align: top;"| Distance | 50,000 light-years SGR 1806-20 is a magnetar, a particular type of neutron star. It has been identified as a soft gamma repeater. SGR 1806-20 is located about 14.5 kiloparsecs from Earth on the far side of our Milky Way galaxy in the constellation of...
. It released gamma rays equivalent to 1036 kW in intensity. This starquake occurred 50,000 light years away. Had the event occurred within a distance of ten light years from Earth, the event could have potentially triggered a mass extinction on Earth.