Explanation of the Earth's gravitational field, emphasizing how USGS scientists measure gravity and portray these measurements on maps. Explains terminology of gravity anomaly maps and their relationship to the rock types and other geologic features.
Links to products of magnetic, gravity, magnetotelluric, and multi-discipline reports and surveys of regions in the U.S. and Antarctica plus geophysical software tools. Some products are in PDF format.
Airborne electromagnetic surveying is used to estimate the character of the permafrost by measuring and monitoring the electrical resistivity, which is affected by lithology, temperature, water, and ice.
Project summary, photos of logging truck, and bibliographies on log interpretation techniques and instrumentation to record geophysical data in wells and test holes for studying ground water hydraulics and evaluate waste disposal sites.
Coordinated studies of the effect of historical mining for mercury, origin and composition of metals in groundwaters and surface waters, history of volcanic and intrusive activity, and the complex geological history of this area.
This publication (Open-File Report 95-479) is a teacher's guide to two U.S. Geological Survey maps that show gravity and magnetic data in contour form superimposed on a LANDSAT satellite image of the San Francisco Bay area.
A method to create qualitative images of thick oil in oil spills on water using near-infrared imaging spectroscopy data. It relies on the organic absorption features of chemical bonds in aliphatic hydrocarbons. The data cannot give oil volume estimates.
A program of studies with instruments to provide accurate and timely data and information on seismic events, including their effects on buildings and structures, employing modern monitoring methods and technologies.
The USGS Seismological Laboratory in Albuquerque installs and maintains a world network of seismograph stations, collects the seismic data, and evaluates seismic instruments. Site includes links to ASL publications, earthquake maps and seismic data.
Complex report on the interpretation of aeromagnetic data to study hydrogeology of the San Pedro basin, Cochise County, Arizona determining geologic structure, basin fill and depth to water. Online version of a CD-ROM publication.
This site is designed to provide information on federal interagency and cooperative developments related to coastal sand and gravel resources and management issues along the Atlantic continental margin.
Summary of an investigation of the Cascadia subduction zone with detailed density-modeling experiments of the crust and mantle along two transects across Vancouver Island and the Canadian margin and the other on the margin of central Oregon.
Information on earthquakes in central California and the San Francisco region with links to four types of field studies, deep seismic investigations, geotechnical investigations, shallow seismic imaging, and airborne geophysical surveys.
Access to InfoBank, an online data catalog, to browse or retrieve coastal and marine geology program information, images, and data on gravity, bathymetry, seismic activity, magnetics, samples, facilities, cruises and equipment.
Overview of fractured rock research aimed at understanding the movement of water through fracture networks, and characterize field conditions influencing contaminant migration. Includes programs and publications.
Crustal imaging and characterization home with links to projects on earth science technologies including geophysical, geochemical, and isotope studies, online publications and data, and newsletter Minerals News.
Provides links to explanatory materials for the layperson, including information on concepts behind earthquake maps, the use of probability, what the maps mean, how they are made, and answers to frequently asked questions.
Information on earthquake activity, earthquake science, and earthquake hazard reduction with links to news reports, products and services, educational resources for teachers, glossary, and current U.S. earthquake activity map.
Place to provide information about ground shaking associated with significant earthquakes. A questionnaire to let us know what you felt following an earthquake in the United States or in other countries.
Answers to a wide variety of questions (FAQs) about earthquakes, such as dictionary of terms, earthquake activity and probabilities, common myths, faults, plate tectonics, and earthquake measurement techniques.
Links to Louisiana statewide aquifer and well information by locating parish on a map or selecting parish, aquifer, region, or type of ground-water data (real-time water levels or geophysical data) from lists.
We put seismic monitoring instruments into 20 VA hospital buildings, connected with computers that analyze their data to determine rapidly the structural health of the buildings in the event of earthquakes.
Description of the hydrogeologic framework of Antelope Valley and Bedell Flat in west-central Nevada north of Reno-Sparks area. Gravimetric and seismic-refraction methods were used in the study. Report available in PDF format or HTML format.
Description of earthquake that was felt in Joshua Tree region (1999) and links to earthquake summary, shaded relief map, aerial photos of the rupture zone, shaking intensity maps, damage reports, and seismograph network map.
Study of the probability of a major earthquake in San Francisco Bay region with colored map and links to relevant publications. Text also available in PDF format and graphic available in Illustrator or Photoshop format.
Bibliography of publications relating to the research of the United States Geological Survey, Woods Hole, MA dating from 1962 to the present with links to publications that are online. Listed by series and with a free text search option.
Description of the work on paleomagnetism at the USGS Rock Magnetics Laboratory in Menlo Park, California with an overview of geomagnetic polar reversals, paleosecular variation, intensity, magnetic susceptibility, and rock magnetism analysis.
Instructions on how to build a protective outdoor seismic vault used as stations for broadband seismic sensors that respond to seismic energy, temperature, and atmospheric pressure for the United States National Seismic Network in PDF format.
Webpage based on USGS Open File Report 98-139 links to information on the San Francisco Bay estuary to study dredge disposal effects, fish habitats, sediment transport, rock pinnacles and navigation, and consequences of a large oil spill.
Georeferenced high-resolution mapping of bathymetry of the West Florida Shelf, Gulf of Mexico of areas suspected to be critical benthic habitats for fisheries. Includes links to images, data, metadata, and TIFF image files.
Information on world earthquake activity with links to facts and lists on large earthquakes, earthquake e-mail notification, hazards and preparedness, educational links, news and highlights and other seismic information.
Overview of USGS programs related to geomagnetism including observatories, data, program services, links to models, charts, and movies, program contacts, Intermagnet, Geomag, publications, and bibliographies.
Homepage for the Nearshore Benthic Habitats Project for mapping geophysical characterization of the coastal sea floor to identify benthic fish and shellfish habitat with links to research cruises and preliminary results.
Compilation of P-wave data from the Indian subcontinent Deep Seismic Sounding (DSS) profiles that used refraction and reflection techniques to provide an estimate of crustal thickness across the subcontinent.
An automated system for rapidly estimating the shaking distribution, number of people and settlements exposed to severe shaking, and range of possible fatalities and economic losses. A color-coded alert suggests levels of appropriate response.
Specialized monitoring systems installed in a VA hospital in Memphis, TN will help us to design safer hospitals and other buildings and to prevent loss of life in this and similar earthquake-prone areas.
Description of seismograms and how they are produced by drum recorders and electronic instruments with real-time seismograms for Northern California and Long Valley, California and representative seismograms for types of earthquake activity.
We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ observations with a time-dependent flow rate model derived from pressure readings taken after the Macondo well was shut in for the well integrity test.
Report presenting the data, automatic interpretations, cross sections, and resistivity maps of direct current electrical soundings at the Amargosa Desert Research Site near Beatty, Nevada using a Schlumberger array.
Study addresses questions and concerns related to limited sand resources along the Louisiana shelf and their implications to long-term relative sea-level rise and storm impacts, using newly acquired geophysical and vibracore data.
Presentation of maps of the seismic properties of North America and the surrounding ocean basins compiled from seismic refraction and reflection data, earthquake studies, and surface wave analyses showing crustal thickness and geologic provinces.
Description of Long Island Sound projects and links to research topics, data, publications, photos, and technology on sediment transport, sea floor mapping, contaminant sampling, sediment texture, and environmental issues.
Fact sheet describing plans for a San Andreas Fault Observatory at Depth (SAFOD) by drilling into the fault to install instruments for long-term monitoring near the location of the magnitude 6 Parkfield earthquakes.
Fact sheet on the sea-floor mapping facility at Woods Hole describing state-of-the-art technology used to produce accurate geologic maps of the sea floor and reporting on its data-acquisition, data-processing, and archiving capabilities.
Online booklet giving an introduction to the concept of plate tectonics and complements the information on the map This Dynamic Planet published in 1994 by the U.S. Geological Survey (USGS) and the Smithsonian Institution.
Evansville, Indiana, is near the Wabash Valley and New Madrid seismic zones and has experienced minor damage from earthquakes in the past 200 years. This fact sheet describes three types of USGS earthquake hazard maps for Evansville and surrounding areas.
National Strong-Motion Program home page with links to program news, recent events, and datasets of digitized accelerograms downloadable as PC (*.zip) and Unix (*.tar.z) files, data processing, stations, research, publications, and personnel.