In Oceanside, geophysics addresses the coastal and alluvial conditions defined by marine terraces, the San Luis Rey River valley, and shallow groundwater. Our non-invasive surveys comply with ASTM D6432 for GPR and local California Building Code Chapter 18A for site classification. A [GPR survey](ground-penetrating-radar) precisely maps underground utilities, rebar, and voids in sandy formations, while [electrical resistivity (VES)](electrical-resistivity-ves) delineates saline intrusion and lithologic boundaries critical for foundation design near the coast.
These methods support geotechnical investigations for bridges, slope stability assessments, and post-seismic evaluations. Seismic [refraction and reflection](refraction-reflection) tomography generates shear-wave velocity profiles (Vs30) required by CBC and ASCE 7-22 for seismic site class determination. Complementing this, [HVSR microtremor survey](hvsr-microtremor-survey) rapidly estimates fundamental site period in urban lots with restricted access. This integrated approach delivers the subsurface certainty that Oceanside’s complex stratigraphy demands.