How is the magnitude of an earthquake calculated?
We can calculate the magnitude of an earthquake using the following equation: M=log(IIN) Here the variables represent:
- M the magnitude of the earthquake.
- I the amplitude of the seismic wave or the intensity.
- IN the arbitrary amplitude or arbitrary intensity.
What is earthquake moment magnitude?
The moment magnitude scale (MMS; denoted explicitly with Mw or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake’s magnitude (“size” or strength) based on its seismic moment. It was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori.
What is the magnitude of M S?
Magnitude Types
| Magnitude Type | Magnitude Range | Distance Range |
|---|---|---|
| Mwr (regional) | ~4.0 to ~6.5 | 0 – 10 degrees |
| Ms20 or Ms (20sec surface wave) | ~5.0 to ~8.5 | 20 – 160 degrees |
| mb (short-period body wave) | ~4.0 to ~6.5 | 15 – 100 degrees |
| Mfa (felt-area magnitude) | any | any |
What is the description of a 5.0 5.9 magnitude in a Richter scale?
Richter scale of earthquake magnitude
| magnitude level | category | effects |
|---|---|---|
| 5.0–5.9 | moderate | some damage to weak structures |
| 6.0–6.9 | strong | moderate damage in populated areas |
| 7.0–7.9 | major | serious damage over large areas; loss of life |
| 8.0 and higher | great | severe destruction and loss of life over large areas |
How is moment magnitude measured?
The moment magnitude scale is based on the total moment release of the earthquake. Moment is a product of the distance a fault moved and the force required to move it. It is derived from modeling recordings of the earthquake at multiple stations.
What is ML and MW in earthquake?
The magnitude is a number that characterizes the relative size of an earthquake. Several scales have been defined, but the most commonly used are (1) local magnitude (ML), commonly referred to as “Richter magnitude”, (2) surface-wave magnitude (Ms), (3) body-wave magnitude (Mb), and (4) moment magnitude (Mw).
What is the moment magnitude scale do?
The moment magnitude scale was designed to produce a more accurate accounting of the total energy released by an earthquake, and it calculates the earthquake’s magnitude more accurately than other measures—such as the Richter scale (ML), the body-wave scale (mb), and the surface-wave scale (MS).
How does the moment magnitude scale work?
The moment magnitude scale measures energy release as a function of the rigidity of the earth, multiplied by the amount of displacement that takes place along a fault, as well as the size of the area which was displaced. Recently, the moment magnitude scale has begun to replace the Richter scale as the most commonly used of the two.
What is the magnitude of a moment?
Moment magnitude measures the size of events in terms of how much energy is released. Specifically, moment magnitude relates to the amount of movement by rock (i.e. the distance of movement along a fault or fracture) and the area of the fault or fracture surface.
What is the definition of moment magnitude?
moment magnitude scale – a logarithmic scale of 1 to 10 (a successor to the Richter scale ) that enables seismologists to compare the energy released by different earthquakes on the basis of the area of the geological fault that ruptured in the quake. geology – a science that deals with the history of the earth as recorded in rocks.
How do you calculate magnitude of earthquake?
The formula for calculating the magnitude of an earthquake, M = 3/2log(S/S0).