- © 2012 by The Society of Exploration Geophysicists
Over the past 30 years, geophysical methods have assumed a much more prominent and integral role in many investigations where subsurface features have environmental and engineering importance. In fact, the field once referred to as “environmental and engineering geophysics” has broadened to include other applications (e.g., archeology, forensics), and is now commonly referred to more generally as “near-surface geophysics.” It is difficult to precisely define near-surface geophysics, and the definition will likely depend on whom you ask. However, we define it as the use of geophysical methods to investigate the zone between the surface and hundreds of meters into the Earth's crust. Applications include, but are not limited to, potable water management, engineered infrastructure and construction, site clearance, gas storage, natural-hazard mitigation, mining, forensics, and archaeology. Although the same physical principles are relevant for any target depth, the high degree of near-surface heterogeneity, rapid change in physical properties, and proximity to the free surface often dictates that dominant processes and therefore key assumptions differ between the near-surface and deeper investigations. While near-surface geophysics shares many technical and cultural attributes of oil and gas exploration, the majority of near-surface geophysicists practice under different economic drivers and conditions.