3-D ground-penetrating radar surveys on a frozen river lagoon

Monica Moldoveanu-Constantinescu, Robert R. Stewart

Ground-penetrating radar (GPR) surveys were acquired at Bowness Park, Calgary to characterize the ice and shallow subsurface of a frozen lagoon. We used Sensors and Software Inc.'s 250-MHz NOGGIN and Smart Cart system as well as a Pulse EKKO 4 system with 100 MHz antenna. 3-D GPR surveys were acquired over the frozen lagoon in two consecutive years (2003 and 2004). Hyperbolic velocity analysis gave ice velocities of about 0.15 m/ns with velocities decreasing in the sediments to about 0.11 m/ns. We interpret the ice thickness to be about 0.4 m from the GPR profiles, which is consistent with auger holes drilled through the ice. Channel sediments and stratigraphy beneath the ice are interpretable from the 3D radar reflectivity. Penetration of the 250 MHz data reached about 2 m at several locations in the area.