Quaternary fault and fold database of the United States

Quaternary fault and fold database of the United States
Name	Quaternary fault and fold database of the United States
Type	Geological database
Country	United States
Established	1990s
Maintained by	United States Geological Survey
Subject	Neotectonics, Seismotectonics

Quaternary fault and fold database of the United States The Quaternary fault and fold database of the United States is a national catalog compiling mapped faults and folds active during the Quaternary period across the United States. It supports earthquake engineering, seismic hazard assessment, geologic mapping, and hazard communication for agencies such as the United States Geological Survey, Federal Emergency Management Agency, and state geological surveys. The database interfaces with academic research at institutions like University of California, Berkeley, Massachusetts Institute of Technology, and Stanford University and informs planning by entities including the California Geological Survey and municipal emergency managers.

Overview

The database catalogs Quaternary-age tectonic fault and fold features, providing spatial extents, activity classifications, slip rates, and evidence summaries tied to publications from organizations such as the National Research Council, American Geophysical Union, and the Seismological Society of America. It integrates mapped traces with attribute tables usable in Geographic Information Systems linked to projects like the National Map and hazard models by the United States Geological Survey and Pacific Northwest Seismic Network. By standardizing entries, it enables comparison among regional compilations such as the New Madrid Seismic Zone studies, the Wasatch Fault assessments, and investigations of the San Andreas Fault system.

History and development

Initiated in the 1990s by the United States Geological Survey and collaborators at universities and state surveys, the database grew from legacy paper maps produced by entities like the California Division of Mines and Geology and published atlases such as the Quaternary Geology of the United States. Subsequent enhancements incorporated digital cartography advances from the U.S. Geological Survey National Geospatial Program and standards influenced by committees of the International Association of Seismology and Physics of the Earth’s Interior and the International Union of Geological Sciences. Major updates paralleled national events including reassessments after the 1994 Northridge earthquake and studies following the 1906 San Francisco earthquake centennial analyses.

Data content and structure

Entries include feature name, type (e.g., strike-slip, reverse), geometry, Quaternary activity class, preferred slip-rate, last-known surface-rupturing age, and supporting references to publications by authors at institutions like University of California, Santa Cruz, Ohio State University, and University of Alaska Fairbanks. Attribute schemas adhere to metadata practices promoted by the Federal Geographic Data Committee and link to bibliographic sources such as journals like Bulletin of the Seismological Society of America, Geology (journal), and Journal of Geophysical Research. Spatial data are provided in formats compatible with ArcGIS and QGIS and are cross-referenced with seismic catalogs maintained by the National Earthquake Information Center.

Methodology and criteria

Compilation follows criteria for Quaternary activity established by panels of experts from the United States Geological Survey, state geological surveys, and academic centers such as California Institute of Technology. Sources include trenching studies, paleoseismic investigations, geomorphic analysis using Light Detection and Ranging data, and stratigraphic correlations published in venues like the Geological Society of America. Fault classifications reflect consensus frameworks used by the National Seismic Hazard Model and consider paleoseismic chronologies constrained by methods employed at laboratories such as the U.S. Geological Survey Geologic Hazards Science Center.

Applications and uses

Practitioners in earthquake engineering, urban planning offices like those in Los Angeles, utility operators including Pacific Gas and Electric Company, and infrastructure agencies such as Federal Highway Administration use the database for siting, seismic design, and risk assessment. Researchers model rupture scenarios for events akin to the 1857 Fort Tejon earthquake or the 1811–1812 New Madrid earthquakes and integrate data into probabilistic seismic hazard analyses informing building codes and retrofit priorities adopted by municipalities and states.

Limitations and uncertainties

The database is constrained by variable data quality across regions, uneven research density (e.g., extensive coverage in California versus sparse mapping in parts of the Great Plains), and interpretive differences among investigators from universities and agencies. Chronologic controls may be limited where radiocarbon labs or Optically Stimulated Luminescence studies are lacking, and some entries reflect competing hypotheses published in journals like Quaternary Research and conference proceedings of the American Quaternary Association.

Access and maintenance

Managed by the United States Geological Survey with contributions from state geological surveys, universities, and federal partners, the dataset is periodically updated through review panels and technical workshops drawing participants from institutions such as University of Washington and Oregon State University. Data dissemination aligns with national geospatial practices promoted by the National Geospatial Advisory Committee and supports web services consumed by clients including municipal planners, researchers, and international collaborators.

Category:Geologic databases Category:United States Geological Survey