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.

A new USGS website (http://qfaults.cr.usgs.gov/) summarizes geologic, geomorphic, and geographic information on about 2000 Quaternary faults and fold-related faults in the U.S. This online database contains information on faults and associated folds in the United States that are believed to be sources of M>6 earthquakes during the Quaternary time period. The Quaternary period encompasses the past 1.6 million years, and is the period of geologic time that is most relevant to earthquake studies.

The Quaternary Fault and Fold Database has information of interest to the general public, the educational community, and the seismic hazards and engineering communities. A graphical map interface with links to the text descriptions and fault information makes it easy for anyone to locate fault and fold information for a particular area by pointing and clicking. The database can also be searched by a single term or a combination of geologic, geographic, or seismologic terms. If you want a fancier interface, you can opt for the ArcIMS version which allows users to zoom, pan, query, and link to the database, as well as turn on and off geographic layers such as state boundaries, roads, and trench locations. For the technical audience, the data is also downloadable for GIS applications.

The database includes information such as geologic setting, fault orientation, fault type, sense of movement, slip (activity) rate, recurrence (repeat) interval, and the time of the most recent surface faulting event.

Ten years in the making, this massive collection of data, which is estimated to contain about 10,000 pages of content, was accomplished with the cooperation and assistance of state geological surveys as well as individuals in the academic and engineering communities. Although still under development, it will serve the needs of a wide variety of users in the lower 48 states. Future revisions to the database will include information for Alaska and Hawaii.

The Quaternary Fault and Fold Database will be the archive for USGS seismic-hazards information on faults and fault-related folds in the United States. It is dynamic, thus providing an easy mechanism to update the information on a regular basis. It will provide geologic information on the probable sources of past, current and future earthquakes.

The USGS serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.