Dr. Elise Rumpf has been granted a National Science Foundation (NSF) Earth Sciences postdoctoral fellowship to carry out a research and education plan at the Lamont-Doherty Earth Observatory at Columbia University. She will study the effects of substrate composition, grain size, and roughness on the emplacement of lava flows. Lava heat loss and motion are influenced by thermal and mechanical interactions with the underlying substrate, which can affect the mobility, duration, extent and morphology of an active lava flow. This work will enhance the current understanding of lava flow emplacement and lava flow hazards by quantifying substrate influence on lava flow morphology and advance rate. Results will be used to improve existing models that predict the paths of lava flows to reduce potential threats to property, agriculture, and local infrastructure in communities living near active volcanoes. The knowledge gained through this project will also be applicable to lava flows on other planets and moons in our Solar System providing key information on past environmental conditions and planetary thermal evolution. This project will be used to educate the public about lava flows and their hazards. In addition to mentoring undergraduate and graduate students through internships and lectures at Columbia University, Dr. Rumpf will invite the public to view lava pour events and lava-analog experiments in person or through webcasts.
Lava morphology and emplacement are complex processes influenced by thermal and mechanical interactions with the underlying substrate. Substrate roughness may affect the mobility of a lava flow directly, by acting as either a barrier or a conduit, or more subtly, as flow irregularities may develop at the lava-substrate boundary. The thermal conductivity of a substrate, dependent on composition and grain size, can affect lava flow heat loss, and thus influence the duration a flow is active. This project will focus on improving our knowledge of these interactions through: 1) Experiments using polyethylene glycol wax as an analog to lava flows to obtain initial estimates of the effects of substrate roughness on lava emplacement; 2) Experiments in which molten basalt will be poured onto a variety of substrates to determine relationships between flow behavior and heat loss and substrate type; 3) Numerical simulations replicating experimental results and expanded conditions to predict emplacement environments found on other planetary bodies; and 4) A survey of the roughness and topography at volcanic regions on the Earth, the Moon, and Mars to improve lava flow prediction methods on Earth and advance our understanding of planetary volcanic evolution.
