Vertical derivatives of aeromagnetic and gravity datasets are routinely used as an aid to the interpretation process because they enhance detail and sharpen geophysical anomalies. Since they are a form of high-pass filter they also have the undesirable property of enhancing noise. Traditionally, the second order vertical derivative of a dataset would be calculated, and if this proved too noisy ...

Sixty heat flow values ranging from 38 to 157 mW/m have been estimated for Armenia from geothermal gradient determinations in 90 locations and a limited number of thermal conductivity determinations. The highest values of heat flow (90-157 mW/m) occur in the central part of the country, which is characterized by vigorous Quaternary volcanic activity, manifestations of thermal springs, intensive...

First posted August 22, 2023 For additional information, contact: Geology, Minerals, Energy, & Geophysics Science CenterU.S. Geological SurveyBuilding 19, 350 N. Akron Rd.P.O. Box 158Moffett Field, CA 94035 Aeromagnetic surveys were conducted to improve understanding of the geology and structure in northeastern California, a region predominantly covered by Quaternary Tertiary, mainly Neogene, v...

This study mapped and analyzed groundwater potential using two different models, logistic regression (LR) and multivariate adaptive regression splines (MARS), and compared the results. A spatial database was constructed for groundwater well data and groundwater influence factors. Groundwater well data with a high potential yield of ≥70 m3/d were extracted, and 859 locations (70%) were used for ...

This article discusses optimizing the process of extracting linear structure from magnetic field data through modeling geological bodies. Lineament analysis is an important tool for geophysical fields interpretation, but results can be ambiguous and dependent on many factors, including features area, method interpreter’s opinion. The reviews methods lineament types extraction, as well conductin...

Aeromagnetic surveys of the Hawaiian Islands have revealed that the pr imary magnetic anomalies associated with the islands are dipole anomalies caused by the intrusive rocks of the volcanic centers and rift zones. Comparisons of the direction of magn etization indicated by the dipole anomalies with results of laboratory measurements on iavas show that in many cases the lavas possess reverse po...

Present study was carried out to delineate groundwater prospect zones and identification of artificial recharge sites using Indian remote sensing satellite (IRS) 1D PAN geocoded data on 1:12,500 scale and Survey of India (SOI) topographical sheets. The information based on lithology, geomorphology, soil, land-use/ land-cover, structures/lineament, slope, drainage and hydrology were generated an...