electrical resistivity

Advanced Geophysical Services (AGS) provides non-intrusive subsurface investigation services for environmental, engineering, and construction projects. Formed through the acquisition of Advanced Geological Services by EPI Geophysics, AGS brings over 30 years of experience in geophysical investigations and subsurface characterization, with in-house licensed Professional Geologists and experienced geophysicists. The company supports projects across Pennsylvania, New Jersey, New York, Connecticut, Delaware, Maryland, and beyond.

borehole geophysicsGround Penetrating Radarmicrogravityoil tank sweepSeismic methodssubsurface investigationutility locating and mapping

Certerra Subsurface delivers integrated subsurface investigation services including geophysical surveys, drilling, utility investigation, leak detection, and infrastructure assessment. The company provides technology-enabled testing, inspection, and certification services to assure quality and advance innovation in infrastructure, helping engineers, mine operators, and environmental professionals understand underground conditions and reduce uncertainty.

airborne surveysCCTV pipe inspectiondownhole geophysical imagingdrillinggeophysicsGround Penetrating Radarleak detectionpotholingSamplingseismic refractionutility surveying

Cultural Resource Analysts, Inc. (CRA) is a full-service cultural resource consulting firm established in 1983 in Lexington, Kentucky. A certified small business with over 40 years of experience, CRA provides archaeology, architectural history, historic preservation, and compliance services to public and private sector clients across the country.

archaeological surveyarchival researchbioarchaeological analysiscartographycemetery excavation and reintermentearth conductivitygenealogical researchgeophysical surveyGISGround Penetrating Radarhistoric preservation planningLiDARMagnetometryremote sensingSfM photogrammetry

GeoServ, Inc. (GSI) is a northern California-based engineering consulting firm headquartered in Mount Shasta, California, and is a Certified Disabled Veteran & Women Owned Small Business. Since 2010, GSI has provided engineering services for electric utility, transportation, water resources, dam safety, public infrastructure, renewable energy, emergency response, and watershed and stream restoration projects throughout California, Oregon, and Nevada.

air drillingCone Penetration Test (CPT)construction inspection and oversightengineering & designground penetrating radar (GPR)mud drillingrock core drillingrock core samplingrotary auger drillingseismic testingStandard Penetration Test (SPT)

Global Geophysics provides a full range of marine, terrestrial and borehole geophysical services to communities including aggregates and quarry, archaeological investigation, civil engineering, communication, construction, dam construction and safety, geotechnical engineering, groundwater exploration, mining, port and harbor development, power and energy, transportation, tunneling, vessel and aircraft recovery, and waste management. Based in Redmond, WA, USA.

bathymetryBorehole GPRBorehole LoggingBorehole seismic methodsCoring and SamplingCrosshole ResistivityElectromagneticsGravityInduced Polarization ImagingMagnetic MethodMagnetometryMarine Seismic ReflectionMarine Seismic RefractionNewton GradiometerResistivity ImagingSeismic methodsSide-Scanning SonarTime Domain ReflectrometryUnderwater Video