Lava River Cave IMU (Moasure) Traverse

Abstract

Lava River Cave near Flagstaff, Northern Arizona, is a lava tube approximately 1.25 km long and 15 m wide. The cave has been previously mapped by manual sketching and, recently, mobile light detection and ranging (LiDAR; King et al., 2023). However, large discrepancies remain in the absolute positioning of the cave passage, likely owing to poor GPS reception in the pine forest. To address this inconsistency, we performed a 350 m traverse of the cave passage starting at the cave entrance and ending at the pillar where the tube bifurcates and reconnects, while tracking the movement using a Moasure 2 PRO, a motion-based measuring tool (inertial measurement unit). The resulting 3D spatial dataset in Cartesian coordinates was then georeferenced using a straight path north of the cave and the nearby parking lot as base stations.