Sub-surface imaging of cross-valley alluvial fans: Using ground penetrating radar (GPR) and electric resistivity ground imaging (ERGI) to determine Holocene sedimentation thicknesses in trunk valleys

This research utilized ground penetrating radar (GPR) and electrical resistivity ground imaging (ERGI) with multiple smart electrodes to investigate Holocene cross-valley alluvial fans in the upper Columbia River Valley of the Rocky Mountain Trench, B.C. Field experiments determined the thicknesses of these alluvial fans. From thickness, volume of adjacent inter-fan valley fills along the course of the Columbia River would be estimated.;Field experiments compared the accuracy of ERGI data modeling to GPR imaging, the latter of which has proven over the past decade to be a highly accurate shallow geophysical technique. Four alluvial fan datasets are presented in which ERGI data is directly compared to GPR data collected along identical transects.