Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

This is an AMP page - Open full page! for all features.

Search is the most efficient way to navigate the Engineering ToolBox!

Earthquake Scales

Sponsored Links

The intensity of an earthquake can be described by scales as

  • Moment magnitude (MW)
  • Mercalli intensity
  • Richter magnitude (ML)

Be aware when using the table below that the Mercalli scale is a measure of the local shaking and the Richter scale is a measure of the total energy in the whole earthquake and that the scales are not directly convertible.

Earthquake Scales
 Mercalli IntensityRicher MagnitudeMoment MagnitudeActual Observation of the Earthquake
Instrumental I 2 1.0 - 3.0 Micro earthquakes, usually not felt - detected by instruments
Feeble II 2 3.9 Often felt, especially on upper floors - detected by instruments
Slight III 3 4.0 Felt noticeably indoors, vibration like passing vehicles, cars may rock
Moderate IV   4.9 Felt indoors by many, felt outdoors by few. Dishes and doors disturbed, like a heavy truck nearby, walls-cracking sound
Rather Strong V 4 5.0 Felt by most people, slight damage. Some dishes and windows broken, some cracked plaster, trees disturbed
Strong VI 5 5.9 Felt by all, many frightened and run outdoors. Damage minor to moderate
Very Strong VII 5 - 6 6.0 Everyone runs outdoors. Much damage to poor designed buildings, some chimneys broken, noticed by people driving cars
Destructive VIII 6 6.9 Everyone runs outdoors. Damage moderate to major. Minor damage to well designed structures, major damage in poor designed structures. Chimneys, columns and walls falls. Heavy furniture turned. Well water changes, sand and mud ejected
Ruinous IX 7 7.0 Can cause serious damage over larger areas. Major damage in all structures, ground cracked, pipes broken, shift foundation
Disastrous X 7 - 8   Major damage, most masonry and frame structures destroyed. Ground badly cracked, landslides, water sloshed over river banks, rails bent
Very Disastrous XI 8   Almost all masonry structures destroyed, bridges fall, big fissures in ground, land slumps, rails bent greatly
Catastrophic XII >8   Devastating in areas several thousand miles across. Total destruction, Ground surface waves seen, objects thrown in the air. All constructions destroyed.
  • Mercalli Intensity - based on actual observations of the damage - can not be measured on instruments
  • Moment Magnitude - based on energy released - logarithmic scale
  • Richter Magnitude - based on the movement of a needle - logarithmic scale
Sponsored Links

Related Topics

Environment

Climate, meteorology, solar, wind, emissions and environmental related engineering resources.

Related Documents

Beams Natural Vibration Frequency

Estimate structures natural vibration frequency.

Beaufort's Wind Scale

The Beaufort description and observation scale for wind and wind speed.

Fujita-Pearson Tornado Intensity Scale

A tornado intensity rating scale.

Hurricane Intensity Scale

The Saffir-Simpson hurricane damage potential scale.

Sponsored Links

Search Engineering ToolBox

Search is the most efficient way to navigate the Engineering ToolBox!

SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics on the AMP pages. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.