PPT Slide
What is Near Surface Engineering Geophysics and why do we do it?
Geophysics*:
Near Surface Geophysics: non invasive imaging of a variety of near surface (upper 100 m)* properties and structures
Near Surface Geophysics
NSG - applications
Geophysical applications all come down to (and/or)
What can you expect from doing a geophysical survey - I
What can you expect from doing a geophysical survey - II
What can’t you expect from doing a geophysical survey
Geophysical Measurements
Brookhaven methods - I
Magnetic mapping Observe main & induced fields Induced field relates to proximity to material with high or low magnetic susceptibility Ex: dyke with k of 0.001 surrounded by sed.rocks with k=0 Observe: anomaly near dyke anomaly non symmetric anomaly size 40 nT
Brookhaven methods - II
Conductivity principle - I
Conductivity principle - II
Brookhaven methods - 3 Ground Penetrating Radar
Case studies - Site assessment
Conductivity survey of abandoned industrial site in New York
Property evaluation for housing site
The case of the missing tank
Summary
Email: versteeg@ldeo.columbia,edu
Home Page: http://www.ldeo.columbia.edu/eeg