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Interactive AL Earthquake Map

Historical Earthquakes in Alabama

AL Seismic Stations

AL Real-time Seismic Data

Additional AL Quake Info

Automated Quake Notification

Earthquake and Disaster Preparedness

New Madrid Seismic Zone

 

EARTHQUAKES IN ALABAMA

 

 

Earthquakes are fairly common in the eastern half of the United States. Four zones of frequent earthquake activity affecting Alabama (right) are the New Madrid Seismic Zone, the Southern Appalachian Seismic Zone, the South Carolina Seismic Zone, and the Bahamas Fracture Seismic Zone. 

 

Most of the earthquakes we experience in Alabama are associated with the Southern Appalachian Seismic Zone (an extension of the East Tennessee Seismic Zone) that runs along the Appalachian Mountains from the northeastern corner into the central part of the state and the Bahamas Fracture Seismic Zone in southern Alabama.

 

 

 

 

 

 

INTERACTIVE EARTHQUAKE MAP OF AL

 

 

 

 

 

 

Legend for interactive earthquake map.

 

Earthquakes are not uncommon in Alabama. The interactive map to the left shows epicenters of historical Alabama earthquakes from 1886 to 2011 and surface and basement faults. To read more information on individual earthquakes or faults, click the feature on the map.

 

Not all web browsers or connection speeds support the below interactive map. If you do not see the map to the left, click here.

 

GIS shapefiles and metadata of earthquake epicenters and surface faults in Alabama (as seen on the map to the left) are available on our Geospatial Hazards Data page. For a catalog of Alabama earthquakes (as of October 2012), click here to download the Excel file.

 

 

 

 

 

 

 

HISTORICAL EARTHQUAKES IN ALABAMA

 

 

 

Photo of damage to a chimney of a house damaged in the Fort Payne earthquake.

 

Building damage caused by the Fort Payne 2003 earthquake included broken windows, minor cracks in masonry (below), and chimneys that collapsed or broke at the top (above). Some schools in the area were closed as a precaution although no structural damage was recorded.

 

Photo of damage to a house damaged in the Fort Payne earthquake.

 

Fort Payne Earthquake, 2003

 

Seismogram of the Fort Payne earthquake.

 

On Tuesday morning, April 29, 2003, a 4.9 magnitude earthquake occurred in DeKalb County, Alabama, 10 miles northeast of Fort Payne. The quake was felt in multiple southeastern states (below). The earthquake was deep enough to suppress significant damage in Fort Payne, the closest city, although the event did damage weaker masonry.

 

Shaking intensity levels across the region from the Fort Payne earthquake.

 

Photo of landslide in the Fort Payne earthquake.

 

The Fort Payne magnitude 4.9 quake caused the development of minor landslides such as the one above, sinkholes like the one below and, muddied the underground water supply for the town of Valley Head, causing the pumps to shut down.

 

Photo of a sinkhole in the Fort Payne earthquake.

 

 

 

Escambia County Earthquake, 1997

 

Shaking intensity levels across the region from the Escambia County earthquake.

 

 

The second largest quake recorded by seismographs in Alabama occurred on October 24, 1997, in Escambia County (left) and was a 4.9 magnitude event. Effects from the shaking were seen as far away as Lawrence County where a berm around a pond failed, spilling water and fish across a road. Large cracks also developed in sand along a creek (right). Shaking from the quake was felt into Mississippi.

 

The southwestern part of Alabama has had minimal seismic activity recorded by seismographs. However, the largest historical earthquake known for this area occurred in 1781 in the Pensacola area. The quake is recorded to have caused structural damage (read more below).

 

Cracks in the ground from the Escambia County earthquake.

 

Irondale Earthquake, 1916

 

The largest known earthquake in Alabama happened October 1916 in northern Shelby County (below). Intensity was estimated to be a VII on the Modified Mercalli Scale, indicating a moderate earthquake. Geologists estimate the magnitude was about 5.1.

 

Shaking intensity levels across the region from the Irondale earthquake.

 

Pensacola Area Earthquake, 1781

 

According to USGS earthquake records, a large magnitude (6-7) earthquake occurred in the Pensacola area in May of 1781. Although there were no fatalities recorded in association with the shaking, damage reported included ammunition racks torn from barrack walls and a leveled house in the vicinity.

 

This earthquake, and the Escambia County earthquake in 1997 were both associated with basement faults that run from the Florida panhandle through southwestern Alabama and into southeastern Mississippi.  These faults are believed to be associated with the Bahamas Fracture Seismic Zone, a crustal zone of weakness associated with the formation of the Gulf of Mexico.

 

More Historical Alabama Quakes

 

Additional information on earthquakes in Alabama and the role of Alabama Emergency Management Agency (AEMA) can be found on the AEMA website in the brochure “Earthquake Awareness for Alabama Residents.” Click the brochure to the right to go to the website, or click here to download the pdf.

 

The USGS also has additional information on earthquakes in Alabama and our neighboring states. Click here to read more.

 

Thumbnail and link to the Alabama Emergency Management Agency Earthquake Awareness brochure.

 

 

 

SEISMIC STATIONS

 

The U.S. Geological Survey (USGS) installed a broadband seismic station in Bibb County in June 2001. The station (photos below) was funded through a grant from the AEMA and arranged by an agreement between AEMA, the USGS, and the Geological Survey of Alabama (GSA) and is part of the Advanced National Seismic System (ANSS) coordinated by the USGS. The site for the station is located near the middle of the state in Bibb County in the southernmost exposure of hard Paleozoic rocks.

Seismic station in Bibb County. 

 

The station is able to monitor even small earthquakes that generally go unnoticed but may be precursors of future larger quakes. Information from the sensors goes to an onsite computer (left), which then relays the information by satellite (far right) to USGS headquarters in Golden, Colorado.

Seismic station in Bibb County. Seismic station in Bibb County.

 

The station’s sensors are placed 4 feet underground and can sense everything from vehicles passing by to earthquakes on the other side of the earth. The two sensors at the station are buried in large water-tight containers. A small shed houses the accompanying electronics (above middle and right).

 

 

Seismic stations around the region.

 

Seismic stations in and around Alabama (locations from International Registry of Seismograph Stations).

 

 

ALABAMA SEISMIC DATA – REAL TIME !

 

Curious to see what seismic stations in Alabama are recording today? Copy and paste one of the url’s listed below to go to its corresponding helicorder (a compiled record of vibrations recorded by the station).

 

BRAL, Brewton, AL (USNSN, Broadband) – S AL

 

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LRAL, Lakeview Retreat, AL (USNSN, Broadband) – Central AL

 

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FPAL, Ft Payne, AL (CERI, Broadband) – NE AL

 

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PWLA, Pickwick Lake, AL (CERI, Shortperiod) – NW AL

 

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PLAL, Pickwick Lake (SLU, Broadband) – NW AL

 

HSV, Huntsville (Public Seismic Network, Broadband) – N AL

(currently not shown on map)

 

 

 

 

 

ADDITIONAL ALABAMA EARTHQUAKE INFORMATION

 

 

Earthquake Hazards Map

 

To produce your own Earthquake Hazards Map such as the one to the right, click here to go to the USGS Custom Hazards Mapping tool.  The colors on the map refer to an estimate of the probability of exceeding a certain level of ground shaking in percent g (gravitational force) in 50 years. This is dependent on magnitudes and locations of likely earthquakes, occurrence frequency, and properties of the rocks and sediments of the area.

 

For additional information on how these maps are generated, click here to go to the USGS  webpage on “Earthquake Hazards 101.”

 

For the U.S. National Seismic Hazards Maps 2008 edition and 2010 revisions, click here.

 

An earthquake hazards map from USGS Custom Hazards Mapping tool.

Seismic Engineering

 

For seismic design information for engineers, please refer to the USGS webpage “Seismic Design Maps and Tools for Engineers

 

 

Earthquake Probability Mapping

 

For earthquake probability mapping of an area of interest in Alabama, click here to refer to the USGS 2009 Earthquake Probability Mapping page. The page requires input of a latitude/longitude of interest (such as for that of a city) and an area map (such as the one to the right) is produced showing estimated earthquake probabilities computed from the source model of the 2008 USGS-National Seismic Hazard Mapping Project (NSHMP) update.

 

For documentation on the USGS online program that produces the maps such as the one to the right, click here.

Probability map from the USGS Earthquake Probability Mapping page.

 

 

Alabama Earthquake Notification

Additional Questions?

If you would like to receive a text message or email when an earthquake occurs in Alabama, click here to sign up through the USGS automated Earthquake Notification System.

If you are looking for additional Alabama-specific earthquake information not found on these pages, please contact Sandy Ebersole, sebersole@gsa.state.al.us, 205-247-3613. For earthquake information specific to other states, please refer to that state’s geological survey or the USGS.

 

 

 

 

 

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