Understanding the Richter Scale: How Earthquake Strength is Measured and What It Means

A simple guide to interpreting earthquake magnitudes and their impact

 

The recent 8.2 magnitude earthquake in Myanmar, which sent tremors across Thailand and neighbouring countries, has highlighted the importance of understanding how earthquake strength is measured. 

 

The Richter scale, a widely used tool, provides a way to quantify the energy released during these seismic events.

 

Developed by Charles F. Richter in 1935, the Richter scale is a logarithmic scale. 

 

This means that each whole number increase on the scale represents a tenfold increase in the amplitude of the seismic waves and roughly a 31.6-fold increase in the energy released. 

 

Therefore, an 8.0 magnitude earthquake releases significantly more energy than a 7.0 magnitude quake.

 

  

The scale categorises earthquakes based on their magnitude, with each level corresponding to different impacts:

Microearthquakes (Less than 2.0): These are so minor that they are rarely felt by humans and are only detectable by sensitive instruments. They cause no damage.

Minor Earthquakes (2.0 - 2.9): These are slightly stronger and may be felt, but they still cause no damage to structures.

Light Earthquakes (3.0 - 3.9): These can cause noticeable shaking and minor damage is possible, especially to poorly constructed buildings.

Moderate Earthquakes (4.0 - 4.9): These cause noticeable shaking of indoor items and produce rattling noises. While generally not causing significant damage, they can still cause minor damage.

Moderate to Strong Earthquakes (5.0 - 5.9): These can cause significant damage to buildings and infrastructure, especially in densely populated areas.

Strong Earthquakes (6.0 - 6.9): These cause extensive damage in populated areas, including building collapses and ground displacement.

Major Earthquakes (7.0 and above): These are capable of causing widespread destruction of buildings and infrastructure, leading to significant loss of life. The recent 8.2 magnitude earthquake falls within this category.
  



 

It's important to note that earthquakes of magnitude 8.0 to 10.0 are relatively rare, occurring roughly once a year. Earthquakes of magnitude 10.0 or higher have never been recorded.

 

The recent earthquake serves as a reminder of the power of these natural events and the importance of understanding the Richter scale to gauge their potential impact. By understanding this scale, we can better appreciate the severity of earthquakes and prepare for their consequences.

(2025/03/29-00:00)