EAR PF: The Stability of Viscous Lavas: Understanding the Driving Processes and Greatest Hazards

Carr Brett B, Flagstaff AZ

Investigators

Abstract

Dr. Brett B. Carr has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education plans at Lamont-Doherty Earth Observatory (LDEO), Columbia University. Silicic effusion eruptions are long-lived and present a persistent hazard to the populations living around them. The primary hazard of these eruptions is the development and collapse of instabilities in the erupted lava that form dangerous block-and-ash pyroclastic flows, plumes, and ash clouds. This investigation will examine instabilities in active silicic lava flows and identify precursors to their collapse. During field campaigns in Sinabung Volcoano, Indonesia, the PI will collect aerial and thermal photography to determine changes in the internal structure of the flow/dome and potential precursors to collapse. The information from the volcano in Indonesia will be compared with data from the domes at Colima, Mexico, and Santiaguito, Guatemala. The results from this investigation will improve hazard assessments and risk mitigation in regions affected by effusive eruptions. The new methods and insights stemming from this project will allow volcano observatories to make more detailed and quantitative assessment of instabilities and to provide more effective warning to communities at risk. The education plan will focus on mentoring of an undergraduate student in research related to the investigation. In addition, Dr. Carr will participate in public outreach and education activities at LDEO. This project addresses the processes controlling the stability of high-viscosity, high-silica lava extruded during an effusive eruption. The investigation will address the following questions: which processes promote or suppress the instability and collapse of viscous lava, and how do these vary over the course of an eruption? what relationships exist between the cause of an instability, the size, and the frequency of the resulting collapse? and how can emerging technologies be utilized to mitigate the risk from lava instability? Dr. Carr will investigate lava instabilities by creating a time-series of topographic change of currently active silicic effusive eruptions and identifying precursors to collapse. The principal investigator will reconstruct or collect digital terrain models (DTMs) of these flows and then analyze them using a numerical slope stability analysis program to quantify the risk of collapses for each time period, and to infer the internal structure of the flow/dome. Dr. Carr will conduct a field campaign at the ongoing eruption of Sinabung Volcano, Indonesia, and utilize an emerging technology - low-cost aerial and thermal photography - to generate a sequence of DTMs of the flows. In addition, the investigator will collaborate with scientists working on domes at Colima, Mexico and Santiaguito, Guatemala, to exchange topographic data of these domes. The result will be shared with staff at volcano observatories to be integrated into monitoring and hazard assessment activities.