Department of Emergency Management and Security
	
	
			
	
	
				
		
	
					
	
			
			
				
						
																						What It Is
																
														
								An earthquake is a shaking of the ground that can cause damage to buildings and infrastructure. Following an earthquake, fire is a significant risk due to gas leaks and water pressure failures.
Earthquake strength is described by the Richter Scale, which measures amplitude on a logarithmic basis – meaning that each whole number correlates to a 10-fold increase in earthquake amplitude, or a 30-fold increase in total energy released. Earthquakes below 5 on the Richter scale may be felt but rarely cause damage; earthquakes of 9 and up cause complete regional devastation. 
For context, the 2011 Virginia earthquake rated 5.9 on the Richter Scale; the 1995 Northridge, California earthquake 6.7; the 2017 Mexico City earthquake 8.2; the 2011 Fukushima, Japan earthquake 9.1. 
Virginia is one of 45 states or territories in the US at risk of earthquakes.
							
      
						 
				
				 
			 
		 
	
	
		
			
			
									
												
						
								
									
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