Analysis of terrestrial ground-based lindar datasets on active lava flow processes and the geomorphology of Pu'u O'o, Hawaii

Since 1983 the eruptions from the Pu'u O'o vent in the Kilauea rift zone on the island of Hawaii have provided researchers numerous opportunities to study effusion rates, emplacement controls and the geomorphology of lava flows. This thesis utilizes recently acquired subcentimeter topographical data acquired by a ground-based LiDAR system to measure the volumetric growth and effusion rate of the PKK flow over a 3-day period in February 2007, during the waning stages of its eruption from the Pu'u O'o vent. The mean effusion rate calculated for this study area was 0.02 m /s. This calculation is based on a spatial coverage of 4886 m2 for the survey area over a time period of 48 hr. The calculated range of fractal dimension values for a pahoehoe flow was 1.16 to 1.23, measured along the flow margins utilizing the divider method and the software program FRAGSTATS. This range of values is typical for pahoehoe flow morphology. Topographic profiles were also created to describe the changing geomorphic characteristics of the lava field in an effort to describe the subcentimeter changes in surface roughness. A tumulus and flow lobes were easily detected due to the high resolution (mm scale) of the Digital Elevation Models. This project demonstrates the utility of ground-based LiDAR for high precision topographic surveys, which can refine what is known about geomorphic processes including lava emplacement controls and erosion. Further use of LiDAR may aid in hazard and risk mitigation in populated areas as well as the exploration of extraterrestrial planetary surfaces.