Researchers at Embry-Riddle Aeronautical University are conducting “sky-high seismology” research, investigating when vertical ground movement during an earthquake acts like a giant piston, sending energy upward through the vibration of atoms and molecules. The vibration produces acoustic waves that amplify as they travel through low-density layers of the atmosphere and then roil the ionosphere, a region of charged particles about 80 to 600 km above Earth.

The effects created by the waves in the ionosphere provide complex signatures that the researchers are modeling and quantifying. The process is a unique opportunity to characterize earthquakes, which often occur in remote areas or offshore, and therefore provide scant clues to their location, magnitude and shape. Such information is critical to understanding how earthquakes behave – and to predicting earthquake-induced phenomena, such as tsunamis, which occur when underwater earthquakes shake the sea floor.

“We will comprehensively investigate how earthquake-induced acoustic waves travel from the ground to the upper atmosphere, to calibrate observations of their signals as a complement to seismic measurements,” said Dr. Pavel Inchin, a research scientist at Computational Physics, Inc. (CPI), who earned his Ph.D. at Embry-Riddle and is the principal investigator on the project. The research is designated as a Collaborative Research project and funded by the National Science Foundation under the Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) program, with grants to CPI and Embry-Riddle.

The signatures produced by the earthquake-generated acoustic waves that reach the ionosphere are in the form of variations in the density of its charged-particle plasma. Those variations are detected by receivers connected to the Global Navigation Satellite System, the global system that provides GPS, providing the researchers with extensive ionospheric data.

Dr. Jonathan Snively, co-principal investigator, university research fellow and professor in the Department of Physical Sciences, said the project will help in the detection and characterization of other sources of acoustic waves besides earthquakes, such as explosions, rocket reentries and meteors.

Regarding underwater earthquakes, Snively said the research “directly benefits the development of ionosphere-based tsunami early-warning systems,” adding that the underwater events may generate seismic waves that seem similar according to seismometers at the Earth’s surface, even if their motion and potential to generate tsunamis are different.

Another Embry-Riddle co-principal investigator in the collaboration is Dr. Matthew Zettergren, university research fellow and professor in the Department of Physical Sciences. His and Snively’s advanced modeling frameworks are “essential,” Inchin said, “to advancing how we can use the GPS signals to accurately quantify and study seismic activity from space.” Researchers from Kyoto University in Japan will help with state-of-the-art seismicity modeling, according to Inchin.

Bjorn Bergsson, who is scheduled to earn his Ph.D. at Embry-Riddle in December and will then continue on the project as a research scientist at the university’s Center for Space and Atmospheric Research (CSAR), will “help drive the numerical simulations, analyze the results and validate our models against real-world observations,” Inchin said.

Bergsson said he is excited to investigate “how the ionospheric signals I have spent much of my Ph.D. studying can be used in a completely new way to better understand earthquakes and processes occurring at the Earth’s surface.”

Dr. Aroh Barjatya, professor of Engineering Physics and interim executive director of CSAR, said he is incredibly proud of the collaborative effort behind this milestone project.

“The ingenuity shown by our researchers and students in CSAR highlights how space physics and advanced modeling can be applied to real-world challenges, turning ionospheric data into potentially actionable insights for global safety.”