Fault facts
A 6.4 magnitude earthquake struck in the southeastern Turkish province of Hatay Monday, just two weeks after a deadly 7.7 earthquake struck southeastern Turkey and northern Syria on Feb. 6. Today we look at devastating earthquakes around the globe.
To date, some 47,000 fatalities have been recorded in Syria and Turkey, with the death toll still expected to rise.
The Ring of Fire, also called the Circum-Pacific belt, is the zone of earthquakes surrounding the Pacific Ocean — and about 90% of the world’s earthquakes occur here.
The next most seismic region (5%-6% of earthquakes) is the Alpide belt, which extends from the Mediterranean region eastward through Turkey, Iran and northern India.
Earthquake size is measured over an extremely broad range of scales that can be difficult to articulate and equally difficult to envision. Measured by its seismic moment, a magnitude-9 earthquake is 1,000 times bigger than a magnitude-7 earthquake and 1 million times bigger than a magnitude-5.
Some fault line facts from the USGSThe San Andreas Fault is not a single, continuous fault, but rather is actually a fault zone made up of many segments. Movement may occur along any of the many fault segments along the zone at any time. The San Andreas Fault system is more than 800 miles long — and in some spots is as much as 10 miles deep.
The average rate of motion across the San Andreas fault zone during the past 3 million years is 2 inches per year. This is about the same rate at which your fingernails grow. Assuming this rate continues, scientists project that Los Angeles and San Francisco will be adjacent to one another in approximately 15 million years.
The earliest reported earthquake in California was felt in 1769 by the exploring expedition of Gaspar de Portola while the group was camping about 30 miles southeast of Los Angeles.
The epicenter of an earthquake is the location directly above the hypocenter on the surface of the earth.
The hypocenter of an earthquake is the location beneath the earth’s surface where the rupture of the fault begins.
Whole lot of shakingIt is estimated that there are 500,000 detectable earthquakes in the world each year. About 100,000 of those can be felt. and 100 of them cause damage.
Each year, Southern California has about 10,000 earthquakes. Most of them are so small that they are not felt. Only several hundred are greater than magnitude 3.0 and only about 15 to 20 are greater than magnitude 4.0. If there is a large earthquake, however, the aftershock sequence will produce many more earthquakes of all magnitudes for many months.
The world’s deadliest recorded earthquake occurred in 1556 in central China. It struck a region where most people lived in caves carved from soft rock. These dwellings collapsed during the earthquake, killing an estimated 830,000 people. In 1976, another deadly earthquake struck in Tangshan, China, where more than 250,000 people were killed.
Florida and North Dakota have the smallest number of earthquakes in the U.S. Alaska is the most earthquake-prone state and experiences a magnitude-7 earthquake almost every year, and a magnitude-8 or greater earthquake on average every 14 years.
Sources: California Department of Insurance, California Earthquake Authority, USGS, Southern California Earthquake Center, ShakeOut.org, California Department of Conservation