Geologist Alexander Lusk investigates slickenlines on the Moab fault near Arches National Park (Utah, USA).
What is a "Quaternary" fault?
A Quaternary fault is one that has been recognized at the surface and that has moved in the past 1,600,000 years (1.6 million years). That places fault movement within the Quaternary Period, which covers the last 2.6 million years.
Related
What is a fault and what are the different types?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake - or may occur slowly, in the form of creep. Faults may range in length from a few millimeters to thousands of kilometers. Most faults produce repeated displacements over geologic time. During an earthquake, the...
What is the relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
Earthquakes occur on faults - strike-slip earthquakes occur on strike-slip faults, normal earthquakes occur on normal faults, and thrust earthquakes occur on reverse or thrust faults. When an earthquake occurs on one of these faults, the rock on one side of the fault slips with respect to the other. The fault surface can be vertical, horizontal, or at some angle to the surface of the earth. The...
Where can I find a fault map of the United States? Is one available in GIS format?
An online map of United States Quaternary faults (faults active in the last 1.6 million years which places them within the Quaternary Period) is available via the Quaternary Fault and Fold Database. There is an interactive map application to view the faults online and a separate database search function. KML (Google Earth-type) files and GIS shape files are also available for download from the...
How do I find the nearest fault to a property or specific location?
If you are looking for faults in California use: How Close to a Fault Do You Live? (Bay Area Earthquake Alliance) For faults in California and the rest of the United States (as well as the latest earthquakes) use the Latest Earthquakes Map: click on the "Basemaps and Overlays" icon in the upper right corner of the map. check the box for "U.S. Faults". mouse-over each fault to get a pop-up window...
How do I find fault or hazard maps for California?
An online map of faults ( Quaternary Fault and Fold Database of the United States) that includes California is in the Faults section of the Earthquake Hazards Program website. Choose the Interactive Fault Map, or download KML files and GIS shapefiles from the links on the page. USGS hazard maps, data, and tools for California and other parts of the United States are in the Seismic Hazard Maps and...
Why are there no faults in the Great Valley of central California?
The Great Valley is a basin, initially forming ~100 million years ago as a low area between the subducting ocean plate on the west (diving down under the North American plate) and the volcanoes to the east (now the Sierra Nevada mountains). Since its formation, the Great Valley has continued to be low in elevation. Starting about 20 million years ago the tectonics changed in California and instead...
Why are there so many earthquakes and faults in the Western United States?
This region of the United States has been tectonically active since the supercontinent Pangea broke up roughly 200 million years ago, and in large part because it is close to the western boundary of the North American plate. Since the formation of the San Andreas Fault system 25-30 million years ago, the juxtaposition of the Pacific and North American plates has formed many faults in California...
Why are there so many faults in the Quaternary Faults Database with the same name?
Many faults are mapped as individual segments across an area. These fault segments are given a different value for name, number, code, or dip direction and so in the database each segment occurs as its own unique entity. For example, the San Andreas Fault has several fault segments, from letters a to h, and fault segment 1h has segments with age of last fault movement from historic (<150 years) to...
Moab fault near Arches National Park, Utah
Geologist Alexander Lusk investigates slickenlines on the Moab fault near Arches National Park (Utah, USA).
Emerson Fault Offset Channels
A trench across a set of channels laterally offset by the Emerson Fault in the 1992 Landers earthquake. The vertical scarp from the 1992 earthquake is visible behind the trench across the center of the image.
A trench across a set of channels laterally offset by the Emerson Fault in the 1992 Landers earthquake. The vertical scarp from the 1992 earthquake is visible behind the trench across the center of the image.
Geologists examining a paleoseismic trench across the Sawtooth fault, Idaho
Photograph of geologists examining a paleoseismic trench across the Sawtooth fault, Idaho. Trenches like this provide geologists an opportunity to date sediments that were offset by past earthquakes, thus determining the rupture history of the fault. Photo by Zach Lifton, Idaho Geological Survey, September 2022.
Photograph of geologists examining a paleoseismic trench across the Sawtooth fault, Idaho. Trenches like this provide geologists an opportunity to date sediments that were offset by past earthquakes, thus determining the rupture history of the fault. Photo by Zach Lifton, Idaho Geological Survey, September 2022.
Monte Cristo Fault, Nevada
Alex Hatem observes surface deformation from the 2020 Monte Cristo, Nevada, earthquake eroding away, June, 2022.
Alex Hatem observes surface deformation from the 2020 Monte Cristo, Nevada, earthquake eroding away, June, 2022.
Surface faulting from the M7.1 Searles Valley earthquake
Oblique photograph showing surface faulting from the M7.1 Searles Valley earthquake. The dirt track (center) is right-laterally offset approximately 2.5 m (~8 ft).
Oblique photograph showing surface faulting from the M7.1 Searles Valley earthquake. The dirt track (center) is right-laterally offset approximately 2.5 m (~8 ft).
USGS Geologists Inspecting Fault Trace in a Trench
View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
Imperial Fault Motion Across Interstate Hwy 8
Surface fractures and long-term offset of features along the Imperial Fault. Right-lateral fault offset at I-8 due to recurrent movement on the Imperial Fault; view to the east.
Surface fractures and long-term offset of features along the Imperial Fault. Right-lateral fault offset at I-8 due to recurrent movement on the Imperial Fault; view to the east.
Denali Fault: Canwell Glacier
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Totschunda Fault
View southeast along the Totschunda fault.
View southeast along the Totschunda fault.
Fault Trace
Fault surface trace of the Hector Mine fault after the October 16, 1999 M7.1 rupture. (Photo by Katherine Kendrick, U.S. Geological Survey)
Fault surface trace of the Hector Mine fault after the October 16, 1999 M7.1 rupture. (Photo by Katherine Kendrick, U.S. Geological Survey)
Active Emerson Fault
The Emerson fault, one of the segments that ruptured in the M7.2 1992 Landers, Calfornia earthquake.
The Emerson fault, one of the segments that ruptured in the M7.2 1992 Landers, Calfornia earthquake.
San Andreas Fault in SE Coachella Valley
Oblique aerial view of San Andreas Fault (between white arrows) in southeastern Coachella Valley, near Red Canyon; view to the west.
Oblique aerial view of San Andreas Fault (between white arrows) in southeastern Coachella Valley, near Red Canyon; view to the west.
Related
What is a fault and what are the different types?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake - or may occur slowly, in the form of creep. Faults may range in length from a few millimeters to thousands of kilometers. Most faults produce repeated displacements over geologic time. During an earthquake, the...
What is the relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
Earthquakes occur on faults - strike-slip earthquakes occur on strike-slip faults, normal earthquakes occur on normal faults, and thrust earthquakes occur on reverse or thrust faults. When an earthquake occurs on one of these faults, the rock on one side of the fault slips with respect to the other. The fault surface can be vertical, horizontal, or at some angle to the surface of the earth. The...
Where can I find a fault map of the United States? Is one available in GIS format?
An online map of United States Quaternary faults (faults active in the last 1.6 million years which places them within the Quaternary Period) is available via the Quaternary Fault and Fold Database. There is an interactive map application to view the faults online and a separate database search function. KML (Google Earth-type) files and GIS shape files are also available for download from the...
How do I find the nearest fault to a property or specific location?
If you are looking for faults in California use: How Close to a Fault Do You Live? (Bay Area Earthquake Alliance) For faults in California and the rest of the United States (as well as the latest earthquakes) use the Latest Earthquakes Map: click on the "Basemaps and Overlays" icon in the upper right corner of the map. check the box for "U.S. Faults". mouse-over each fault to get a pop-up window...
How do I find fault or hazard maps for California?
An online map of faults ( Quaternary Fault and Fold Database of the United States) that includes California is in the Faults section of the Earthquake Hazards Program website. Choose the Interactive Fault Map, or download KML files and GIS shapefiles from the links on the page. USGS hazard maps, data, and tools for California and other parts of the United States are in the Seismic Hazard Maps and...
Why are there no faults in the Great Valley of central California?
The Great Valley is a basin, initially forming ~100 million years ago as a low area between the subducting ocean plate on the west (diving down under the North American plate) and the volcanoes to the east (now the Sierra Nevada mountains). Since its formation, the Great Valley has continued to be low in elevation. Starting about 20 million years ago the tectonics changed in California and instead...
Why are there so many earthquakes and faults in the Western United States?
This region of the United States has been tectonically active since the supercontinent Pangea broke up roughly 200 million years ago, and in large part because it is close to the western boundary of the North American plate. Since the formation of the San Andreas Fault system 25-30 million years ago, the juxtaposition of the Pacific and North American plates has formed many faults in California...
Why are there so many faults in the Quaternary Faults Database with the same name?
Many faults are mapped as individual segments across an area. These fault segments are given a different value for name, number, code, or dip direction and so in the database each segment occurs as its own unique entity. For example, the San Andreas Fault has several fault segments, from letters a to h, and fault segment 1h has segments with age of last fault movement from historic (<150 years) to...
Moab fault near Arches National Park, Utah
Geologist Alexander Lusk investigates slickenlines on the Moab fault near Arches National Park (Utah, USA).
Geologist Alexander Lusk investigates slickenlines on the Moab fault near Arches National Park (Utah, USA).
Emerson Fault Offset Channels
A trench across a set of channels laterally offset by the Emerson Fault in the 1992 Landers earthquake. The vertical scarp from the 1992 earthquake is visible behind the trench across the center of the image.
A trench across a set of channels laterally offset by the Emerson Fault in the 1992 Landers earthquake. The vertical scarp from the 1992 earthquake is visible behind the trench across the center of the image.
Geologists examining a paleoseismic trench across the Sawtooth fault, Idaho
Photograph of geologists examining a paleoseismic trench across the Sawtooth fault, Idaho. Trenches like this provide geologists an opportunity to date sediments that were offset by past earthquakes, thus determining the rupture history of the fault. Photo by Zach Lifton, Idaho Geological Survey, September 2022.
Photograph of geologists examining a paleoseismic trench across the Sawtooth fault, Idaho. Trenches like this provide geologists an opportunity to date sediments that were offset by past earthquakes, thus determining the rupture history of the fault. Photo by Zach Lifton, Idaho Geological Survey, September 2022.
Monte Cristo Fault, Nevada
Alex Hatem observes surface deformation from the 2020 Monte Cristo, Nevada, earthquake eroding away, June, 2022.
Alex Hatem observes surface deformation from the 2020 Monte Cristo, Nevada, earthquake eroding away, June, 2022.
Surface faulting from the M7.1 Searles Valley earthquake
Oblique photograph showing surface faulting from the M7.1 Searles Valley earthquake. The dirt track (center) is right-laterally offset approximately 2.5 m (~8 ft).
Oblique photograph showing surface faulting from the M7.1 Searles Valley earthquake. The dirt track (center) is right-laterally offset approximately 2.5 m (~8 ft).
USGS Geologists Inspecting Fault Trace in a Trench
View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
Imperial Fault Motion Across Interstate Hwy 8
Surface fractures and long-term offset of features along the Imperial Fault. Right-lateral fault offset at I-8 due to recurrent movement on the Imperial Fault; view to the east.
Surface fractures and long-term offset of features along the Imperial Fault. Right-lateral fault offset at I-8 due to recurrent movement on the Imperial Fault; view to the east.
Denali Fault: Canwell Glacier
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Totschunda Fault
View southeast along the Totschunda fault.
View southeast along the Totschunda fault.
Fault Trace
Fault surface trace of the Hector Mine fault after the October 16, 1999 M7.1 rupture. (Photo by Katherine Kendrick, U.S. Geological Survey)
Fault surface trace of the Hector Mine fault after the October 16, 1999 M7.1 rupture. (Photo by Katherine Kendrick, U.S. Geological Survey)
Active Emerson Fault
The Emerson fault, one of the segments that ruptured in the M7.2 1992 Landers, Calfornia earthquake.
The Emerson fault, one of the segments that ruptured in the M7.2 1992 Landers, Calfornia earthquake.
San Andreas Fault in SE Coachella Valley
Oblique aerial view of San Andreas Fault (between white arrows) in southeastern Coachella Valley, near Red Canyon; view to the west.
Oblique aerial view of San Andreas Fault (between white arrows) in southeastern Coachella Valley, near Red Canyon; view to the west.
Updated Date: April 8, 2025