<strong>Introduction</strong><br /><br />Earthquakes today are more commonly measured by moment magnitude, a scale based on the amount of seismic energy released by the quake. In the magnitude scale, each increase of one whole number translates to 32 times more energy.<br /><br /><em>Sources</em>: CNN, US geological survey, California Institute of Technology (Caltech)<br />
Introduction

Earthquakes today are more commonly measured by moment magnitude, a scale based on the amount of seismic energy released by the quake. In the magnitude scale, each increase of one whole number translates to 32 times more energy.

Sources: CNN, US geological survey, California Institute of Technology (Caltech)
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<strong>Micro</strong><br /><br /><strong>Magnitude</strong>: Less than 3.0<br /><br /><strong>Average number by year: </strong>The U.S. Geological Survey estimates there are 1.3 million quakes per year that register a 2.0 to 2.9. Caltech says there are about 1,000 of those quakes per day and about 8,000 quakes per day that fall in the 1.0 to 1.9 range.<br /><br /><strong>Damage: </strong>little to none<br /><br /><strong>Additional note: </strong>A quake measuring 2.5 to 3.0 is generally the smallest earthquake felt by people. <br />
Micro

Magnitude: Less than 3.0

Average number by year: The U.S. Geological Survey estimates there are 1.3 million quakes per year that register a 2.0 to 2.9. Caltech says there are about 1,000 of those quakes per day and about 8,000 quakes per day that fall in the 1.0 to 1.9 range.

Damage: little to none

Additional note: A quake measuring 2.5 to 3.0 is generally the smallest earthquake felt by people.
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<strong>Minor</strong><br /><br /><strong>Magnitude</strong>: 3.0-3.9<br /><br /><strong>Average number per year</strong>: The U.S. Geological Survey estimates there are about 130,000 minor earthquakes each year. Caltech estimates there are 49,000. <br /><br /><strong>Damage</strong>: Little to none<br />
Minor

Magnitude: 3.0-3.9

Average number per year: The U.S. Geological Survey estimates there are about 130,000 minor earthquakes each year. Caltech estimates there are 49,000.

Damage: Little to none
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<strong>Light</strong><br /><br /><strong>Magnitude</strong>: 4.0-4.9<br /><br /><strong>Average number per year: </strong>The U.S. Geological survey estimates there are 13,000 light earthquakes per year. Caltech puts the number at 6,200. <br /><br /><strong>Damage</strong>: Moderate<br />
Light

Magnitude: 4.0-4.9

Average number per year: The U.S. Geological survey estimates there are 13,000 light earthquakes per year. Caltech puts the number at 6,200.

Damage: Moderate
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<strong>Moderate</strong><br /><br /><strong>Magnitude</strong>: 5.0-5.9<br /><br /><strong>Average number per year</strong>: 800, according to Caltech, or 1,319, according to the U.S. Geological Survey. <br /><br /><strong>Damage</strong>: Considerable<br />
Moderate

Magnitude: 5.0-5.9

Average number per year: 800, according to Caltech, or 1,319, according to the U.S. Geological Survey.

Damage: Considerable
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<strong>Strong</strong><br /><br /><strong>Magnitude:</strong> 6.0-6.9<br /><br /><strong>Average number per year:</strong> 120-134<br /><br /><strong>Damage: </strong>Severe<br /><br /><strong>Notable quakes:</strong> About 5,500 people were killed in January 1995 by a magnitude 6.9 quake in Kobe, Japan. <br /><br />The <a href="http://edition.cnn.com/2014/10/14/us/gallery/1989-california-earthquake/index.html">Loma Prieta earthquake</a> (magnitude 6.9) killed 63 people in October 1989 and caused an estimated $6 billion in damage in California's San Francisco Bay area. It is remembered for occurring just before a World Series game.<br />
Strong

Magnitude: 6.0-6.9

Average number per year: 120-134

Damage: Severe

Notable quakes: About 5,500 people were killed in January 1995 by a magnitude 6.9 quake in Kobe, Japan.

The Loma Prieta earthquake (magnitude 6.9) killed 63 people in October 1989 and caused an estimated $6 billion in damage in California's San Francisco Bay area. It is remembered for occurring just before a World Series game.
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<strong>Major</strong><br /><br /><strong>Magnitude:</strong> 7.0-7.9<br /><br /><strong>Average number per year: </strong>17-18<br /><br /><strong>Damage:</strong> Widespread, heavy<br /><br /><strong>Notable quakes:</strong> A magnitude 7.3 quake killed 110,000 people in Asghabat, USSR, in October 1948.<br /><br />About 70,000-100,000 people were killed in December 1908 by a magnitude 7.2 quake in Messina, Italy.<br /><br />In October 2005, a magnitude 7.6 quake killed 86,000 people in Pakistan.<br /><br />The <a href="http://edition.cnn.com/2015/04/27/world/gallery/ten-deadliest-earthquakes/index.html">deadliest quake</a> in American history registered 7.8 in 1906 and killed an estimated 3,000 people in San Francisco, California. <br /><br />On April 25, 2015, an earthquake in Nepal <a href="http://edition.cnn.com/videos/world/2015/05/12/lv-building-collapse-nepal-earthquake.cnn/video/playlists/new-powerful-earthquake-in-nepal/">registered</a> 7.8, <a href="http://edition.cnn.com/2015/05/10/asia/nepal-earthquake-death-toll/index.html">killing</a> close to 9,000 people and causing $10 billion in damages.
Major

Magnitude: 7.0-7.9

Average number per year: 17-18

Damage: Widespread, heavy

Notable quakes: A magnitude 7.3 quake killed 110,000 people in Asghabat, USSR, in October 1948.

About 70,000-100,000 people were killed in December 1908 by a magnitude 7.2 quake in Messina, Italy.

In October 2005, a magnitude 7.6 quake killed 86,000 people in Pakistan.

The deadliest quake in American history registered 7.8 in 1906 and killed an estimated 3,000 people in San Francisco, California.

On April 25, 2015, an earthquake in Nepal registered 7.8, killing close to 9,000 people and causing $10 billion in damages.
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<strong>Great</strong><br /><br /><strong>Magnitude</strong>: 8.0 and up<br /><br /><strong>Average number per year</strong>: 1<br /><br /><strong>Damage</strong>: Tremendous<br /><br /><strong>Additional note</strong>: There is no upper limit to the magnitude scale, but the highest measurement ever recorded was a 9.5 (Chile, May 1960).<br /><br /><strong>Notable quakes</strong>: A magnitude 8.0 quake killed 255,000 people on July 27, 1976, in Tangshan, China. It's the deadliest earthquake since 1900, when quakes were first measured. <br /><br />Tsunamis resulting from a magnitude 9.0 quake <a href="http://edition.cnn.com/2014/12/25/asia/gallery/tsunami-aceh-10-years/index.html">killed more than 200,000 people</a> in December 2004. The quake struck the coast of Sumatra, Indonesia, and affected countries from Indonesia to African countries bordering the Indian Ocean.<br /><br />On March 11, 2011 a 9.0-magnitude earthquake struck off Japan's coast -- <a href="http://edition.cnn.com/2012/03/09/asia/gallery/japan-one-year-later/index.html">the most powerful to ever hit the country</a>. It triggered a series of tsunamis and led to 16,000 deaths and the meltdown of the <a href="http://edition.cnn.com/2016/03/08/asia/fukushima-five-year-anniversary/index.html">Fukushima nuclear reactor</a>. <br />
Great

Magnitude: 8.0 and up

Average number per year: 1

Damage: Tremendous

Additional note: There is no upper limit to the magnitude scale, but the highest measurement ever recorded was a 9.5 (Chile, May 1960).

Notable quakes: A magnitude 8.0 quake killed 255,000 people on July 27, 1976, in Tangshan, China. It's the deadliest earthquake since 1900, when quakes were first measured.

Tsunamis resulting from a magnitude 9.0 quake killed more than 200,000 people in December 2004. The quake struck the coast of Sumatra, Indonesia, and affected countries from Indonesia to African countries bordering the Indian Ocean.

On March 11, 2011 a 9.0-magnitude earthquake struck off Japan's coast -- the most powerful to ever hit the country. It triggered a series of tsunamis and led to 16,000 deaths and the meltdown of the Fukushima nuclear reactor.
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