Meet David George 

David is a Research Mathematician at the USGS Cascades Volcano Observatory. He develops mathematical models, numerical methods, and open-source software for simulating geophysical flows. His research involves developing numerical algorithms and partial differential equations (PDEs) that describe earth-surface flows like landslides, debris flows, tsunamis, and overland flooding. If that sounds complicated, it is! David has five advanced degrees: B.S. in Physics, B.S. in Biology, and B.A. in Anthropology all from the University of California at Santa Barbara. He holds an M.S. and a Ph.D. in Applied Mathematics from the University of Washington, in Seattle. He also held two post-doctoral positions in mathematics prior to joining CVO in 2008. 

It takes many different specialties to make up a volcano observatory and mathematicians play a critical role.  

Algorithms aren’t just for Social Media 

Maybe you learned about algorithms in math class or have heard about algorithms filtering your social media feed. Whether they are filtering numerical data or cat videos, algorithms work in the same way. An algorithm is a step-by-step list of instructions that tells a computer how to solve a problem. It processes what information it has about a subject and tries to predict an outcome. In the case of social media, based on your past likes, shares and watches, a computer tries to predict what you would like to see next. In the case of volcano monitoring, based on the known and theorized conditions - like material type, grain size, and water content - a computer tries to predict how earth-surface flow hazards are most likely to behave. David does this kind of predictive modeling for lahars (volcanic mudflows) using a program he co-developed called D-Claw. These hazard areas can then be put on maps, taking something incredibly complex and making it usable for communities. 

David uses D-Claw to help emergency managers prepare for hazards

“D-Claw” stands for Debris Conservation Laws and is part of a larger open-source software package known as Clawpack, which is used for studying wave propagation in many scientific fields. D-Claw is used for modeling earth-surface flows like lahars, landslides, and debris flows. The software solves equations that describe the motion of granular-fluid mixtures based on a mathematical model developed by Richard Iverson and David George here at USGS. Understanding the behavior of solid-fluid mixtures is complex and requires combining principles from fluid, solid, and soil mechanics. The development of this model was informed by controlled experiments conducted at the USGS debris-flow flume over the last ~ 30 years. The aim of those experiments was to investigate the complex physics of debris flow motion, including the initiation processes. Experimental work at the flume is ongoing - Learn more about the flume here https://www.usgs.gov/observatories/cvo/news/get-know-cvo-maciej-obryk-and-usgs-debris-flow-flume