How “thunderquakes” could help reveal hidden structures inside the Earth
When that energy reaches the ground, some of it is converted into seismic waves that ripple through the soil and rock beneath—“thunderquakes”
"Thunderquakes": Uncovering Earth's Hidden Structures Through Seismic Waves
When lightning strikes, the resulting shock wave reaches the ground and converts into seismic waves known as "thunderquakes." These vibrations, once poorly understood, can be harnessed to map the Earth's subsurface, including groundwater movement, environmental contamination, sinkholes, and building sites. Researchers have discovered that fiber-optic cables, commonly found in communities worldwide, can transform into thousands of vibration sensors, creating a distributed acoustic sensing system.
By analyzing these thunderquakes using distributed acoustic sensing, scientists have gained unprecedented insights into the subsurface, akin to X-rays imaging the human body. This technique, known as seismic dispersion, allows researchers to detect specific types of seismic waves produced when sound from the atmosphere interacts with the ground.
The most significant of these waves, called air-coupled Rayleigh waves, can penetrate deep below the surface, up to 300 feet (around 100 meters). Identifying "weak zones" where seismic waves travel more slowly than surrounding rock can reveal fractures, caves, and sinkholes, which pose hazards to buildings and infrastructure. The technique demonstrates that atmospheric disturbances, such as thunderstorms, can serve as natural sources of seismic energy, potentially providing insights into hidden structures beneath the Earth's surface.
This method could be particularly useful for monitoring subsurface conditions in karst landscapes, which cover 20% of the world's land and affect nearly a quarter of the global population. The research opens up new possibilities for investigating subsurface conditions on other planets as well, such as Titan, Saturn's moon, where atmospheric disturbances may provide a way to study its subsurface.
Written by urgent.news from Scientific American's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
