Penn State Team Develops Model to Use Thunderstorms for Seismic Imaging
Penn State researchers developed a model to use thunderstorm-induced seismic waves for imaging underground structures, testing it beneath their campus.
Most knowledge about Earth's interior comes from seismic waves, which travel at different speeds depending on properties of the rock they move through, such as whether it is solid or semi-molten, how much water is present, or whether it is fractured. With enough data from enough seismic events, scientists can piece together a picture of what lies at different depths below the surface. Such data often come from natural earthquakes, or from human-triggered waves using explosives in specific areas.
The Penn State team suggests that thunderstorms sit between these two options. Some energy carried by thunder enters the Earth's upper crust, triggering what are termed 'thunderquakes.' For various physical reasons, however, these seismic signals are extremely complex, making it difficult to extract clear signals from them. The team has now constructed a model that can help make sense of this complexity, and used it to reconstruct the terrain beneath the local campus.