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 w