Frequently Asked Questions

What is environmental geophysics?

• Geophysics is the study of earth through the collection and analysis of physical property measurements that are recorded at or near the ground surface. Environmental Geophysics is a subdiscipline within Geophysics and was likely first mentioned in Geotechnical and Environmental Geophysics: Volumes I, II, and III published by the Society of Exploration Geophysicists in 1980.  It is the study of the physical properties of the near subsurface, up to 100's of meters below the ground surface, for problems impacting the environment and human health.  Environmental geophysicists measure the physical properties of the earth to map contaminant plumes, to monitor remediation, and to perform high resolution characterization to aid in understanding complex geologic settings.

• Historically geophysics has been used extensively within the resource extraction industries, such as oil and gas exploration and mining.  These industries use the physical property contrasts of different geologic formations to determine if there is economical value in extracting a particular mineral resource or if there appears to be an oil reservoir to justify an extraction well.  In these industries, geophysical techniques are employed to understand the geology and to guide well placement and extraction or mining techniques.  

• Our understanding of the earth's structure is largely due to our knowlegde of the physics of the earth. For example, seismographs observe the propagation of seismic energy through the many layers of the earth during earthquakes.  A geophysicist is trained to understand how this energy travels through the earth and the different materials that either enhance this propagation or attenuate it.  This has led to our understanding of plate tectonics, the lithosphere, the inner and outer core of the earth, and greatly increase our understanding of our planet.

Why should I care?

• Before performing any medical surgery, proper medical practice includes imaging procedures such as x-ray, MRI, or CAT scan.  These procedures help identify the problem for which the physician can identify and provide a remedy; identify the bone or soft tissue that may need repair, is causing some discomfort, loss of function, or pain.  This remedy may involve invasive surgery wherein the surgeon uses the medical imaging to guide the scalpel and target the cause of the problem.

• Similarly, an earth process investigator, can use environmental geophysics to diagnose an environmental problem and design a remedy.  For example, an investigator may know that a community’s ground water resource is contaminated and threatening human health, but does not know the subsurface distribution of the contamination.  Where did it come from?  Where is it going?  How laterally and vertically extensive is the contaminant distribution?  Where should a monitoring well be installed?  Where should a remediation system be designed and how should it be designed to be most effective in protecting the community from harmful contaminated water? 

• To help answer these questions, an environmental geophysics survey can be performed to understand the physical properties of the subsurface and how these properties are altered by the contamination.  The distribution of the geophysics can help formulate a conceptual site model (CSM), can map the contaminate distribution, and can guide the place of wells and remediation systems to achieve the objective of protecting human health and the environment.  A geophysical image of a site can be used in concert with other site investigative tools to inform decision makers and guide invasive investigations in much the same way that medical imaging guides the physician’s scalpel.

Will it really help?

• Just as the petroleum industry has used geophysics to successfully site multimillion dollar wells, the environmental industry can use geophysics to reduce the number of costly wells, understand the fate and transport of contaminants and assess the effectiveness of remediation methods in 3 and 4 dimensions.

• Environmental geophysics investigations have been shown to aid in the development of high resolution conceptual site models, to guide the placement of extraction and monitoring wells, and to implement remediation efforts that protect fragile and vulnerable ecosystems.

• Peruse the references section of this site to search for case histories found in peer review literature that match your application and objective to determine for yourself if a geophysical investigation may help.

• Additional decision support tools and forward, or predictive models, can help you determine if a geophysical method can, or will, help your needs.