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, a portion of the Quaternary epoch.
I am looking to buy land near the location of a large historical earthquake. I am wondering where the fault line runs. What is the seismic activity in the area today? How did the quake change the contours and elevations of the area?
What is the relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
Ever since the great magnitude 9.2 earthquake shook Alaska 50 years ago today, scientists have suspected that the quake's rupture halted at the southwestern tip of Kodiak Island due to a natural barrier.
The U.S. Geological Survey has a new website that offers a virtual tour of the Hayward fault.
What are the faults in my state and where are they? When did they last have an earthquake? Now you can find out the answer to these questions online through a user-friendly interface developed by the USGS.
In a first of its kind study U.S. Geological Survey (USGS) and Duke University seismologists have used tiny "microearthquakes" along a section of California’s notorious San Andreas Fault to create unique images of the contorted geology scientists will face as they continue drilling deeper into the fault zone to construct a major earthquake "observatory.
Sunday’s magnitude 7.9 earthquake in central Alaska created a scar across the landscape for more than 145 miles, according to surveys conducted the past two days by geologists from the U.S. Geological Survey and the Alaska Division of Geological and Geophysical Survey.
Shaded relief image of the Santa Rosa area showing active faults (black lines) and the detailed rupture pattern of the Rodgers Creek Fault where it crosses central Santa Rosa (in red). The orange, bean-shaped area represents the dense, magnetic body of rock on the east side of the fault beneath Santa Rosa. This body of rock may be largely responsible for the pattern of...
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.
Two faults (located on either side of project geologist Chris Fridrich) cutting Pleistocene fluvial gravels on the northern edge of the Poncha mountain block. These and other young faults exposed in area help reveal the latest kinematic (movement) and paleostress histories of the mountain block.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
View southeast along the Totschunda fault.
The purpose of this map is to show the location of and evidence for recent movement on active fault traces within the Hayward Fault Zone, California. The mapped traces represent the integration of the following three different types of data: (1) geomorphic expression, (2) creep (aseismic fault slip),and (3) trench exposures.
Map of known active geologic faults in the San Francisco Bay region, California, including the Hayward Fault. The 72 percent probability of a magnitude (M) 6.7 or greater earthquake in the region includes well-known major plate-boundary faults, lesser-known faults, and unknown faults. The percentage shown within each colored circle is the probability that a M 6.7 or...
Dark organic-rich beds at top of exposure in fine-grained Quaternary colluvium (?) probably are associated with grade of the fluvial system that was several meters higher than present. Most of the exposure is of underlying Tertiary sediments. Geologic mapping and geochronology of Quaternary terraces will provide constraints on the downcutting history of the Niobrara River...