Overview of NMR for Groundwater Geophysics

Client: Groundwater Markets
Location: International
Overview: A collection of slides provides an short overview of NMR geophysics, including example applications of GMR and Javelin technologies for groundwater investigations. Full Case Study [pdf]

Combination of Logging and Surface NMR with Short Dead Time

Client: Kansas Geological Survey and Stanford University
Location: Lawrence, Kansas
Overview: Logging and surface-based NMR measurements each carry distinct advantages for characterizing the near surface.  Both surface-based GMR and down-hole Javelin logging measurements were collected at the well-characterized Geohydrologic Experimental and Monitoring Site.  The two data sets not only accurately reflect the known subsurface structure, but are also remarkably consistent with one another.  The short dead time of the GMR instrument enables detection of water in the unsaturated zone which is corroborated by results from the Javelin NMR log. Full Case Study [pdf]

Subsurface Characterization in Magnetic Geology using Spin Echoes

Client: United States Geological Survey
Location: White Sulphur Springs, Montana
Overview: Water managers and ranchers in Western Montana can use NMR measurements of water in the near surface to inform regional groundwater flow models and to select appropriate irrigation strategies.  Measured decay times, which are used to estimate subsurface hydrogeologic properties, are sometimes influenced by the presence of magnetic minerals.  Under these conditions, spin echo measurements and rapid pulsing available with the GMR hardware provide more reliable indication of subsurface hydrogeologic properties. Full Case Study [pdf]