INI

Earthquake Magnitude Scale Classification - INI

Earthquake magnitude classification is a system based on magnitude values that quantify the energy released by earthquakes. Originating from the Richter scale (ML), the Moment Magnitude Scale (Mw) is now widely used as the international standard. Magnitude uses a logarithmic scale where each whole number increase represents approximately 32 times more energy release. It is an essential indicator for objectively comparing and evaluating earthquake sizes, from micro earthquakes to great earthquakes.

earthquake magnitude Richter scale moment magnitude hypocenter JMA USGS seismology

[item.magnitude-1]
code=M1
slug=magnitude-1
name=Magnitude 1.0
description=Extremely small earthquakes generally not felt by humans.
effects=Not felt by humans
energyRatio=1

[item.magnitude-2]
code=M2
slug=magnitude-2
name=Magnitude 2.0
description=Small earthquakes that may be slightly felt in quiet locations.
effects=May be slightly felt in quiet locations
energyRatio=32

[item.magnitude-3]
code=M3
slug=magnitude-3
name=Magnitude 3.0
description=Minor earthquakes that may be felt by people indoors.
effects=Felt by people indoors, slight vibration of window glass
energyRatio=1,000

[item.magnitude-4]
code=M4
slug=magnitude-4
name=Magnitude 4.0
description=Light earthquakes felt by many people; may cause minor damage.
effects=Felt by many people, unstable objects may fall
energyRatio=32,000

[item.magnitude-5]
code=M5
slug=magnitude-5
name=Magnitude 5.0
description=Moderate earthquakes that can cause damage to buildings.
effects=Damage to poorly constructed buildings, furniture may overturn
energyRatio=1,000,000

[item.magnitude-6]
code=M6
slug=magnitude-6
name=Magnitude 6.0
description=Strong earthquakes causing damage to buildings over a wide area.
effects=Building damage within ~100 km area, strong shaking lasts ~10 seconds
energyRatio=32,000,000

[item.magnitude-7]
code=M7
slug=magnitude-7
name=Magnitude 7.0
description=Major earthquakes causing serious damage over large areas.
effects=Serious damage over large areas, building collapse, tsunami risk
energyRatio=1,000,000,000

[item.magnitude-8]
code=M8
slug=magnitude-8
name=Magnitude 8.0
description=Great earthquakes causing catastrophic damage over hundreds of kilometers.
effects=Catastrophic damage over hundreds of km, strong shaking ~1 minute, large tsunamis
energyRatio=32,000,000,000

[item.magnitude-9]
code=M9
slug=magnitude-9
name=Magnitude 9.0 and above
description=Extremely rare mega-earthquakes causing devastating damage over 1000+ km.
effects=Devastating damage over 1000+ km, strong shaking ~3 minutes, massive tsunamis
energyRatio=1,000,000,000,000