The challenges of measuring geyser deformation with LiDAR

Schnur, Susan; Soule, Adam

In September 2010 a multi-disciplinary team of geoscientists set up camp for four days at Yellowstone National Park's Lone Star Geyser. The objective of the expedition was to use geophysical methods to characterize eruption cycles in the geyser system. The team deployed several instruments around the geyser cone, including infrared sensors, visible and infrared video, and microphones for capturing acoustic signals. Measurements of water velocity and channel cross-sectional area for the main streams flowing away from the geyser were used to estimate discharge and give an idea of the total water output from the system in each cycle. A Leica ScanStation C10 was also set up on a hill above the geyser in order to map hydrothermal ground deformation. The geophysical instruments recorded distinct eruption cycles at Lone Star, but the LiDAR scans did not show clear cycles of ground inflation and deflation. The question arises: why was LiDAR unsuccessful here? In this article we will describe the scanning results and consider potential sources of error that may have obscured the deformation signal.