Mihan House McKenna ’05, a research geophysicist with the Geotechnical and Structures Laboratory (GSL) at the U.S. Army Engineer Research and Development Center (ERDC) in Vicksburg, Miss., is the recipient of the 2013 U.S. Army Corps of Engineers Researcher of the Year Award.
McKenna received her doctorate in geophysics from SMU’s Huffington Department of Earth Sciences and now holds the position of research faculty member. She maintains an interest in applied research and academics at SMU through her joint supervision of graduate students and service on dissertation committees, according to Brian Stump, Claude C. Albritton Professor of Earth Sciences, who supervised McKenna’s thesis research.
McKenna’s achievement comes as no surprise to Stump. “She reaches out to understand a variety of technologies, and then finds innovative ways to apply them,” he says.
After earning her doctorate, McKenna joined the U.S. Army Corps of Engineers to pursue infrasound research. Infrasound refers to sound that is below the frequency band audible to the human ear and can travel great distances. Scientists measure low-frequency acoustic waves as they move through the atmosphere to monitor many different types of natural and man-made events. Such events can range from shallow earthquakes to volcanic eruptions to nuclear explosions to meteorites passing through the atmosphere. Infrasound study also plays a role in many other research spheres, from cardiology to animal communication.
McKenna’s current investigations apply infrasound experimental techniques, mapping and numerical analysis using high-performance computing to create complex 3D models of structures. The models are used to evaluate the health of buildings, bridges and other structures without having to physically examine them.
“All structures ‘sing’, but we cannot hear the vibrations because the frequencies are below what humans can perceive,” says McKenna, who is also a federally certified bridge inspector as well as a registered professional geologist. “Using the naturally emitted, low-frequency structural acoustics (infrasound), engineers are now able to assess condition, capacity and holistic behavior of large, critical structures from distances of 10 or more kilometers by listening to the music these structures create.”
This type of remote monitoring has many potential applications, from tactical route reconnaissance for the military to evaluating the safety of civilian structures.
McKenna’s area of expertise supports tactical decision making for deployed military expeditionary forces. She directs the Remote Assessment of Critical Infrastructure working group at ERDC, which has research projects with the Department of Defense, Department of Energy, Defense Intelligence Agency, Los Alamos National Laboratory and academic institutions. She supports several ongoing Defense Advanced Research Projects Agency (DARPA) and Defense Threat Reduction Agency (DTRA) programs related to national security.
As an SMU graduate student from 1999 to 2005, she merged her undergraduate interests in physics, acoustics and music with geophysics in the form of infrasound research, comments Robert T. Gregory, chair of Earth Sciences in SMU’s Dedman College. “Mihan came to SMU with a strong background in physics from Georgetown University where she was also an accomplished musician, which helped spark her interest in acoustics.”
As a graduate student, McKenna served as a research assistant supported by funding from the U.S. Air Force. She also excelled in the classroom/laboratory as a teaching assistant in earth science courses. Among the undergraduate courses she assisted with were Stump’s “Earthquakes and Volcanoes” and Gregory’s “Solar System” classes.
At SMU she conducted research in support of the Comprehensive Nuclear Test Ban Treaty and currently serves as an advisory member of the U.S. and International Infrasound Working Groups for the Comprehensive Test Ban Treaty Organization in Vienna, Austria.
– Patricia Ward