Steven W. Anderson

Associate Research Scientist

anderson @psi.edu

Press release on NASA MFR grant to study Mars lava flows

Planetary Volcanology Research

The Morphology of Planetary Lava Flows

The appearance of a lava flow surface can provide volcanologists with information on how the flow formed. The central question that guides most of my research is "can we observe the surface of an active or older lava flow and interpret how the volcano is or was behaving during eruption?"

High-resolution data sets from MOC and THEMIS now permit imaging of small-scale features (e.g. tumuli, crease structures, blocks, levees and compressional ridges) providing an avenue for answering fundamental questions regarding the rates and styles of volcanism on Mars.

Our recently-funded NASA-MFR grant focuses on how four key eruption parameters (underlying topography, the nature of interior pathways composition, and effusion rates) influence the development of small-scale surface features evident in high-resolution data from MOC, MOLA, and THEMIS. For each of the four variables, we have an associated set of laboratory, field and/or modeling tasks that will enable us to modify and extend existing conceptual and quantitative models in order to reach a better understanding of flows displaying small-scale surface features.

The ultimate goal is to develop tools that permit the interpretation of individual volcanic areas on Mars and for subsequent larger-scale regional assessments.

Above: Skylight at Kilauea Volcano (photo by Adrian Anderson)

Below: Senior student Tessa Krueger watching the development of viscous fingers in analog flows at the Waxworks Lab

Planetary Analog Experiments

We are investigating the influence of underlying topography on lava flow surface morphology through a set of experiments using polyethylene glycol wax (PEG) extruded over a simulated hummocky topography (inverted watch glasses) in the Waxworks Lab at Arizona State University.

Hummocky topography is the focus of these experiments because of the tendency for terrestrial mafic flows to display this dominant late-stage surface morphology.

We are also interested in the development of fluid instabilities in lava flow interiors, and how they affect the appearance of a lava flow surface. We are studying viscous-fingering in analog flow interiors and extending our findings to natural flows. Above is an image from the underside of an analog flow, showing the viscous fingers.

I am also working with Dr. Sue Smrekar of JPL on the application of plate bending theory to model the development of inflation features, such as tumuli (below), on terrestrial and planetary flows.

In addition to his position as Associate Research Scientist at PSI, Dr. Anderson is also Professor of Geology and Planetary Science at Black Hills State University.

Return to PSI Main Page