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What do seismologists use that describesthe magnitude of earth?
Wiki User
∙ 11y ago
The moment magnitude scale (MW) provides an estimate of the total energy released in an earthquake and is currently the preferred magnitude scale in use by seismologists .
It is calculated from the seismic moment (M0 - which has the unit of dynes/cm =where 1 dyne/cm = 1x10-7 N/m) which is a measure of the total energy released during an earthquake and is derived based on the elastic moduli of the crust where the earthquake occurred, the length of the slip surface and the cross sectional area of the slip surface as follows:
M0 = G x AFx DF
Where:
G = Shear modulus of the rock mass
AF = Area of the rupture along the fault
DF = average displacement on AF
Seismic moment can also be estimated from the amplitude spectra of seismic waves as recorded by a seismometer.
In order to make the moment magnitude scale (Mw) consistent with older magnitude scales such as the Local Moment (or "Richter") scale the seismic moment (M0) is converted into a logarithmic scale using the following equation:
Mw = 2/3 x log10 x (M0) - 10.7
This ultimately yields a dimensionless number and as such, Moment Magnitude has no units.
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∙ 14y ago
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Do Geologists use the difference in the arrival time of P and S waves at a seismograph to determine the magnitude of an earthquake?
No. Seismologists (a type of geophysicist) use the difference in the arrival time of P and S waves to estimate the distance from the seismometer station to the epicentre of the earthquake.
The scale that measures the strength of an earthquake based on seismic waves and movement along a fault?
The Moment magnitude scale (used for earthquakes larger than magnitude 7) and Richter scales can both be used to measure earthquake magnitude (the energy released) although seismologists now predominately use the moment magnitude scale.Earthquake intensity is measured using the Modified Mercalli Scale or the European Macroseismic Intensity Scale (essentially a tweaked version of the Moddified Mercalli Scale).The Moment Magnitude Scale is used by seismologists to rate the energy released by earthquakes, replacing the now outdated Richter or Local Magnitude Scale (still commonly used in the media).Earthquake severity is measured using the Modified Mercalli Intensity Scale.Please see the related question.
Use apparent magnitude in a sentence?
The apparent magnitude of a star is a measure of its brightness.
What is the unit used to measure shock?
The energy released during an earthquake (termed it's strength or more correctly it's magnitude) is measured using the Moment Magnitude scale, the Richter scale is commonly quoted in the press, but is no longer in common usage by seismologists. The intensity (based on the perceived shaking as well as measured ground accelerations from seismometers) is measured or quantified using the Modified Mercalli scale. Neither of these scales have units, however the Moment Magnitude scale value is derived from the seismic moment which has the units of dyne centimetres. See the Related Links below.
What is apparent magnatude?
It means "apparent" - visible to the naked eye. It is the magnitude of an object as viewed from Earth. The Sun has an apparent magnitude of -26.73 because it is very close to us. However, Sirius, which is actually more luminous, has an apparent magnitude of -1.46 because it is further away from Earth. For this reason we also use absolute magnitude, which is the luminosity of an object at the same distance. Using absolute scales. The Sun has a value of 4.85 and Sirius has a value of 1.42. (NB: The lower the value, the more luminous an object is)
What does moment magnitude scale measures?
The moment magnitude scale (MW) provides an estimate of the total energy released in an earthquake and is currently the preferred magnitude scale in use by seismologists for measuring large (magnitude greater than 7) earthquakes.
Describe the scales that scientists use to measure the magnitude of an earthquake?
The most commonly referred to scale by the press and the public is the Richter scale for measuring earthquake magnitude. However this was actually replaced in the 1970s by the Moment Magnitude scale which is the magnitude scale favoured and in use by seismologists.
What do seismologists measure?
A seismograph is a device that scientists use to measure earthquake severity. It also determine the origination of the tremor and magnitude.
What system do seismologists use today for rating the magnitude of an earthquake?
Earthquake magnitudes are rated using the moment magnitude scale. Moderate and small earthquakes (those with a magnitude below 7) are also measured using the Richter scale. Please see the related question for more information.
Who uses seismograph?
seismologists
Do Geologists use the difference in the arrival time of P and S waves at a seismograph to determine the magnitude of an earthquake?
No. Seismologists (a type of geophysicist) use the difference in the arrival time of P and S waves to estimate the distance from the seismometer station to the epicentre of the earthquake.
What do seismologists use to determine when an earthquake started?
Seismologists use seismograms to calculate when an earthquake started. AND EARTHQUAKES START WHEN ROCK SLIPS SUDDENLY ENOUGH ALONG A FAULT TO CREATE SEISMIC WAVES!
What is difference in each 1 increment of earthquake?
Each increment in the Richter scale represents a ten-fold increase in the shaking magnitude of the earthquake. In most countries, though, seismologists now use the moment magnitude scale. An increment of 1 on this scale represents a 101.5 fold increase in the energy released. 101.5 = sqrt(1000) = approx 32.
The strength of an earthquake is described in the terms of?
The strength of an earthquake is more correctly termed it's magnitude and is measured using a magnitude scale. Currently seismologists use the moment magnitude scale (which was developed to replace the Richter scale in the 1970's). The magnitude sclae is a way of representing the energy emitted during an earthquake. The damage and perceived ground shaking in an earthquake is known as it's intensity and this is measured using the Modified Mercalli scale or (in Europe) the Macroseismic scale. For more information on the types of magnitude and intensity scales, please see the related questions.
Who is the magnitude scale for earthquakes named after?
The local or Richter magnitude scale is named after Charles Francis Richter an American seismologist and geophysicist. Some people use the title Richter-Gutenberg scale to acknowledge the contribution to the scale of Charles Richter's colleague, Beno Gutenberg a fellow geophysicist at the California Institute of Technology. it is worth noting however that geophysicists / seismologists use the moment magnitude scale in place of the Richter magnitude scale when possible as it is more reliable for large magnitude earthquakes (greater than 6.9) and for earthquakes that occur a long distance away from the nearest seismometer station (greater than 600 km).
Explain a stars apparent magnitude and absolute magnitude?
Apparent magnitude is the brightness of an object as seen from Earth without any atmosphere.Absolute magnitude is the brightness of an object as seen from a predetermined distance, depending on the object.For planets, the distance used is 1 AU (Astronomical Units). Stars and galaxies use 10 parsecs which is about 32.616 light years.The dimmer an object is the higher the positive value. The brighter an object is the higher the negative value.Examples:The Sun has an apparent magnitude of -26.74 but an absolute magnitude of 4.83Sirius has an apparent magnitude of -1.46 but an absolute magnitude of -1.42This means that from Earth, the Sun is a lot brighter, but if the Sun was replaced by Sirius, Sirius would be 25 times more luminous.See related links for more information
The scale that measures the strength of an earthquake based on seismic waves and movement along a fault?
The Moment magnitude scale (used for earthquakes larger than magnitude 7) and Richter scales can both be used to measure earthquake magnitude (the energy released) although seismologists now predominately use the moment magnitude scale.Earthquake intensity is measured using the Modified Mercalli Scale or the European Macroseismic Intensity Scale (essentially a tweaked version of the Moddified Mercalli Scale).The Moment Magnitude Scale is used by seismologists to rate the energy released by earthquakes, replacing the now outdated Richter or Local Magnitude Scale (still commonly used in the media).Earthquake severity is measured using the Modified Mercalli Intensity Scale.Please see the related question.
