The Richter scale is a scale of numbers used to tell the power (or magnitude) of earthquakes. Charles Richter developed the Richter Scale in 1935. His scale worked like a seismogram, measured by a particular type of seismometer at a distance of 100 kilometers (62 mi) from the earthquake.
Earthquakes 4.5 or higher on the Richter scale can be measured all over the world. An earthquake a size that scores 3.0 is ten times the amplitude of one that scores 2.0. The energy that is released increases by a factor of about 32.
Every increase of 1 on the Richter scale corresponds to an increase in amplitude by a factor of 10 so therefore, it is a logarithmic scale.
|Descriptor||Richter Magnitude number||Damage caused by the earthquake||Frequency of occurrence|
|Micro||Less than 2.0||Micro (very small) earthquakes, people cannot feel these.||About 8,000 each day|
|Very minor||2.0-2.9||People do not feel these, but seismographs are able to detect them.||About 1,000 per day|
|Minor||3.0-3.9||People often feel these, but they almost never cause damage.||About 49,000 each year (About 134 per day)|
Objects inside houses are disturbed, causing noise. Things are rarely damaged.
|About 6,200 each year (About 17 per day)|
Buildings that are not built well may be damaged. Light objects inside a house may be moved.
|About 800 per year (About 2 per day)|
Moderately powerful. May cause a lot of damage in a larger area.
|About 120 per year|
|Major||7.0-7.9||Can damage things seriously over larger areas.||About 18 per year|
|Great||8.0-9.9||Massive damage is caused. Heavy objects are thrown into the air and cracks appear on the ground, as well as visible shockwaves. Overhead highways may be destroyed, and buildings are toppled.||About 1 per 20 years|
|Meteoric||10.0+||There are no records of anything of this size. The vibration is about the same as that of a 15 mi meteor.||Unknown|
(Adapted from U.S. Geological Survey documents)
The earthquake with the biggest recorded magnitude was the Great Chilean Earthquake. It had a magnitude of 9.5 on the Richter scale and occurred in 1960. Around 6,000 people died because of the earthquake. No earthquake has ever hit 10+ on the Richter Scale.
- Petraglia, M.; R. Korisettar, N. Boivin, C. Clarkson,4 P. Ditchfield,5 S. Jones,6 J. Koshy,7 M.M. Lahr,8 C. Oppenheimer,9 D. Pyle,10 R. Roberts,11 J.-C. Schwenninger,12 L. Arnold,13 K. White. (6 July 2007). "Middle Paleolithic Assemblages from the Indian Subcontinent Before and After the Toba Super-eruption" Archived 2016-03-03 at the Wayback Machine. Science 317 (5834): 114–116. doi:10.1126/science.1141564. PMID 17615356.
- Bralower, Timothy J.; Charles K. Paull and R. Mark Leckie (1998). "The Cretaceous-Tertiary boundary cocktail: Chicxulub impact triggers margin collapse and extensive sediment gravity flows" (PDF). Geology. 26: 331–334. doi:10.1130/0091-7613(1998)026<0331:TCTBCC>2.3.CO;2. ISSN 0091-7613. Archived from the original (PDF) on 2007-11-28. Retrieved 2009-09-03.
- Klaus, Adam (2000). Richard D. Norris; Dick Kroon; Jan Smit. "Impact-induced mass wasting at the K-T boundary: Blake Nose, western North Atlantic". Geology. 28: 319–322. doi:10.1130/0091-7613(2000)28<319:IMWATK>2.0.CO;2. ISSN 0091-7613. Retrieved 2009-09-03.
- Busby, Cathy J. (2002). Grant Yip; Lars Blikra; Paul Renne. "Coastal landsliding and catastrophic sedimentation triggered by Cretaceous-Tertiary bolide impact: A Pacific margin example?". Geology. 30: 687–690. doi:10.1130/0091-7613(2002)030<0687:CLACST>2.0.CO;2. ISSN 0091-7613. Retrieved 2009-09-03.
- Simms, Michael J. (2003). "Uniquely extensive seismite from the latest Triassic of the United Kingdom: Evidence for bolide impact?". Geology. 31: 557–560. doi:10.1130/0091-7613(2003)031<0557:UESFTL>2.0.CO;2. ISSN 0091-7613.
- Simkin, Tom (2006). "This dynamic planet. World map of volcanoes, earthquakes, impact craters, and plate tectonics. Inset VI. Impacting extraterrestrials scar planetary surfaces" (PDF). Robert I. Tilling; Peter R. Vogt; Stephen H. Kirby; Paul Kimberly; David B. Stewart. U.S. Geological Survey. Retrieved 2009-09-03.