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No. There is no evidence of a correlation between mass extinctions and magnetic pole reversals.
Earth’s magnetic field and its atmosphere protect us from solar radiation. It’s not clear whether a weak magnetic field during a polarity transition would allow enough solar radiation to reach the Earth's surface that it would cause extinctions. But reversals happen rather frequently--every million years or so--compared to mass extinctions, which occur every hundred million years or so.
Yes. We can see evidence of magnetic polarity reversals by examining the geologic record. When lavas or sediments solidify, they often preserve a signature of the ambient magnetic field at the time of deposition. Incredible as it may seem, the magnetic field occasionally flips over! The geomagnetic poles are currently roughly coincident with the geographic poles, but occasionally the magnetic...
Although extremely unlikely, it might be possible for a reversal of the Earth's magnetic field to be triggered by a meteorite or comet impact, or even for it to be caused by something more "gentle," such as the melting of the polar ice caps. Self-contained dynamic systems like Earth’s dynamo can have reversals without any outside influence. Reversals of Earth's magnetic field can simply happen...
Yes. There is evidence that some animals, like sea turtles and salmon, have the ability to sense the Earth's magnetic field (although probably not consciously) and to use this sense for navigation.
In a sense, yes. The Earth is composed of layers having different chemical compositions and different physical properties. The crust of the Earth has some permanent magnetization, and the Earth’s core generates its own magnetic field, sustaining the main part of the field we measure at the surface. So we could say that the Earth is, therefore, a "magnet." But permanent magnetization cannot occur...
The Earth's outer core is in a state of turbulent convection as the result of radioactive heating and chemical differentiation. This sets up a process that is a bit like a naturally occurring electrical generator, where the convective kinetic energy is converted to electrical and magnetic energy. Basically, the motion of the electrically conducting iron in the presence of the Earth's magnetic...
Almost certainly not. Since the invention of the magnetometer in the 1830s, the average intensity of the magnetic field at the Earth's surface has decreased by about ten percent. We know from paleomagnetic records that the intensity of the magnetic field decreases by as much as ninety percent at the Earth's surface during a reversal. But those same paleomagnetic records also show that the field...
The Earth's magnetic field does not directly affect human health. Humans evolved to live on this planet. High altitude pilots and astronauts can experience higher levels of radiation during magnetic storms, but the hazard is due to the radiation, not the magnetic field itself. Geomagnetism can also impact the electrically based technology that we rely on, but it does not impact people themselves...
Satellites and ground-based magnetometers are both important for making measurements of the Earth’s magnetic field. They are not redundant but are instead complementary: Satellites provide good geographical coverage for data collection. Ground-based magnetometers are much less expensive and much easier to install than satellites. An array of magnetometers provides coverage from numerous locations...
Space weather can have important consequences for our lives, such as interference with radio communication, GPS systems, electric power grids, the operation and orientation of satellites, oil and gas drilling, and even air travel as high altitude pilots and astronauts can be subjected to enhanced levels of radiation.
Space weather can have important consequences for our lives, such as interference with radio communication, GPS systems, electric power grids, the operation and orientation of satellites, oil and gas drilling, and even air travel as high altitude pilots and astronauts can be subjected to enhanced levels of radiation.
A fossilized Trilobite, Phacops rana africana, an extinct marine invertebrate. Item originally from Alnif, Morocco.
A fossilized Trilobite, Phacops rana africana, an extinct marine invertebrate. Item originally from Alnif, Morocco.
USGS scientist Duane Champion explains the Earth's geomagnetic qualities and the potential for and possible consequences of a geomagnetic shift.
USGS scientist Duane Champion explains the Earth's geomagnetic qualities and the potential for and possible consequences of a geomagnetic shift.
Piecing together the story of a giant meteorite crater beneath the Atlantic coast
By David S. Powars, Geologist, and R.D. Catchings, Geophysicist
Piecing together the story of a giant meteorite crater beneath the Atlantic coast
By David S. Powars, Geologist, and R.D. Catchings, Geophysicist
The Role of Paleomagnetism in the Evolution of Plate Tectonic Theory Video Presentation
Presentation of the award-winning USGS video "Secrets in Stone" (35 minutes), introduced by Jack Hillhouse, Research Geophysicist, and followed by a tour of the USGS Paleomagnetics Laboratory
The Role of Paleomagnetism in the Evolution of Plate Tectonic Theory Video Presentation
Presentation of the award-winning USGS video "Secrets in Stone" (35 minutes), introduced by Jack Hillhouse, Research Geophysicist, and followed by a tour of the USGS Paleomagnetics Laboratory
Rubens coil inside the Rock Magnetics Laboratory on the USGS Menlo Park campus. The function of the Rubens coil is to cancel the earth's magnetic field for thermal demagnetization of core samples. It is constructed of nonmagnetic materials and the control unit is place far enough away from the instrument to avoid interference from its metal components.
Rubens coil inside the Rock Magnetics Laboratory on the USGS Menlo Park campus. The function of the Rubens coil is to cancel the earth's magnetic field for thermal demagnetization of core samples. It is constructed of nonmagnetic materials and the control unit is place far enough away from the instrument to avoid interference from its metal components.
Interior of room 40 inside the tarpaper shacks on the USGS Menlo Park campus, circa 1965. During the early 1960s, three of the key scientists working on the theory of magnetic reversals operated in the Rock Magnetics Laboratory that was housed in these shacks. The Rock Magnetics Laboratory was designated a National Historic Landmark on October 12, 1994.
Interior of room 40 inside the tarpaper shacks on the USGS Menlo Park campus, circa 1965. During the early 1960s, three of the key scientists working on the theory of magnetic reversals operated in the Rock Magnetics Laboratory that was housed in these shacks. The Rock Magnetics Laboratory was designated a National Historic Landmark on October 12, 1994.
Yes. We can see evidence of magnetic polarity reversals by examining the geologic record. When lavas or sediments solidify, they often preserve a signature of the ambient magnetic field at the time of deposition. Incredible as it may seem, the magnetic field occasionally flips over! The geomagnetic poles are currently roughly coincident with the geographic poles, but occasionally the magnetic...
Although extremely unlikely, it might be possible for a reversal of the Earth's magnetic field to be triggered by a meteorite or comet impact, or even for it to be caused by something more "gentle," such as the melting of the polar ice caps. Self-contained dynamic systems like Earth’s dynamo can have reversals without any outside influence. Reversals of Earth's magnetic field can simply happen...
Yes. There is evidence that some animals, like sea turtles and salmon, have the ability to sense the Earth's magnetic field (although probably not consciously) and to use this sense for navigation.
In a sense, yes. The Earth is composed of layers having different chemical compositions and different physical properties. The crust of the Earth has some permanent magnetization, and the Earth’s core generates its own magnetic field, sustaining the main part of the field we measure at the surface. So we could say that the Earth is, therefore, a "magnet." But permanent magnetization cannot occur...
The Earth's outer core is in a state of turbulent convection as the result of radioactive heating and chemical differentiation. This sets up a process that is a bit like a naturally occurring electrical generator, where the convective kinetic energy is converted to electrical and magnetic energy. Basically, the motion of the electrically conducting iron in the presence of the Earth's magnetic...
Almost certainly not. Since the invention of the magnetometer in the 1830s, the average intensity of the magnetic field at the Earth's surface has decreased by about ten percent. We know from paleomagnetic records that the intensity of the magnetic field decreases by as much as ninety percent at the Earth's surface during a reversal. But those same paleomagnetic records also show that the field...
The Earth's magnetic field does not directly affect human health. Humans evolved to live on this planet. High altitude pilots and astronauts can experience higher levels of radiation during magnetic storms, but the hazard is due to the radiation, not the magnetic field itself. Geomagnetism can also impact the electrically based technology that we rely on, but it does not impact people themselves...
Satellites and ground-based magnetometers are both important for making measurements of the Earth’s magnetic field. They are not redundant but are instead complementary: Satellites provide good geographical coverage for data collection. Ground-based magnetometers are much less expensive and much easier to install than satellites. An array of magnetometers provides coverage from numerous locations...
Space weather can have important consequences for our lives, such as interference with radio communication, GPS systems, electric power grids, the operation and orientation of satellites, oil and gas drilling, and even air travel as high altitude pilots and astronauts can be subjected to enhanced levels of radiation.
Space weather can have important consequences for our lives, such as interference with radio communication, GPS systems, electric power grids, the operation and orientation of satellites, oil and gas drilling, and even air travel as high altitude pilots and astronauts can be subjected to enhanced levels of radiation.
A fossilized Trilobite, Phacops rana africana, an extinct marine invertebrate. Item originally from Alnif, Morocco.
A fossilized Trilobite, Phacops rana africana, an extinct marine invertebrate. Item originally from Alnif, Morocco.
USGS scientist Duane Champion explains the Earth's geomagnetic qualities and the potential for and possible consequences of a geomagnetic shift.
USGS scientist Duane Champion explains the Earth's geomagnetic qualities and the potential for and possible consequences of a geomagnetic shift.
Piecing together the story of a giant meteorite crater beneath the Atlantic coast
By David S. Powars, Geologist, and R.D. Catchings, Geophysicist
Piecing together the story of a giant meteorite crater beneath the Atlantic coast
By David S. Powars, Geologist, and R.D. Catchings, Geophysicist
The Role of Paleomagnetism in the Evolution of Plate Tectonic Theory Video Presentation
Presentation of the award-winning USGS video "Secrets in Stone" (35 minutes), introduced by Jack Hillhouse, Research Geophysicist, and followed by a tour of the USGS Paleomagnetics Laboratory
The Role of Paleomagnetism in the Evolution of Plate Tectonic Theory Video Presentation
Presentation of the award-winning USGS video "Secrets in Stone" (35 minutes), introduced by Jack Hillhouse, Research Geophysicist, and followed by a tour of the USGS Paleomagnetics Laboratory
Rubens coil inside the Rock Magnetics Laboratory on the USGS Menlo Park campus. The function of the Rubens coil is to cancel the earth's magnetic field for thermal demagnetization of core samples. It is constructed of nonmagnetic materials and the control unit is place far enough away from the instrument to avoid interference from its metal components.
Rubens coil inside the Rock Magnetics Laboratory on the USGS Menlo Park campus. The function of the Rubens coil is to cancel the earth's magnetic field for thermal demagnetization of core samples. It is constructed of nonmagnetic materials and the control unit is place far enough away from the instrument to avoid interference from its metal components.
Interior of room 40 inside the tarpaper shacks on the USGS Menlo Park campus, circa 1965. During the early 1960s, three of the key scientists working on the theory of magnetic reversals operated in the Rock Magnetics Laboratory that was housed in these shacks. The Rock Magnetics Laboratory was designated a National Historic Landmark on October 12, 1994.
Interior of room 40 inside the tarpaper shacks on the USGS Menlo Park campus, circa 1965. During the early 1960s, three of the key scientists working on the theory of magnetic reversals operated in the Rock Magnetics Laboratory that was housed in these shacks. The Rock Magnetics Laboratory was designated a National Historic Landmark on October 12, 1994.
