Welcome to brain Stuff, a production of iHeart Radio, Hey brain Stuff, Lauren Bobo bomb Here. In the same way that ultra violet light and infrared light exist outside what the human eye can perceive, sound waves exist beyond the frequencies of what humans can hear. When those sound waves are higher frequency than what we can hear, we call them ultrasonic, and when they're lower frequency, we call them infrasonic.
Several natural sources, including volcanoes, avalanches, earthquakes, and meteors, produce infrasonic waves, also called infrasound. Animals like elephants and whales may communicate with infrasound, and man made inventions like wind turbines can generate these sounds too. Detecting infrasonic waves is one of the key ways that governments can monitor for nuclear bomb tests. That's because infrasonic waves decay very slowly, and when they're large enough, they can wrap around the
globe several times before dissipating. And it turns out that tornadoes can produce unique infrasonic waves even before tornado genesis, which is when the storm forms an hour or more before. Scientists have known about the tornado infrasound connection for several decades, but to learn more about this process and to better understand how humans could harness this information, a group of scientists is developing a long distance, passive way of listening
in on tornadoes. In doing so, we'd be able to deal with the fact that three fourths of all current tornado warnings are false alarms and thus too often ignored or not taken seriously. Infrasound could represent another source of data to add to our arsenal one, Brian Elbing, and Oklahoma State University Mechanical and Aerospace engineering professor, said in a press release discussing this research. By monitoring tornadoes from hundreds of miles away, will be able to decrease false
alarm rates and possibly even increase warning times. Elbing his team built special listening devices using microphones sensitive to low frequencies that were then placed inside of containers with noise holes and arranged in a triangle for precision measurements. The goal was to separate regular wind noise from tornado noise. Elbing said, a wind noise is incoherent, so if you average it over a large space, it will sum up
to zero. Conversely, tornado infrasound is coherent, meaning waves look alike over large distances, so the pressure waves add together and contain information. This new capability could mean that storm chasers trying to gather data about tornadoes would be able to take fewer risks in their research. Imagine drones equipped with special infrasonic microphones, for instance, flying in the vicinity
of storms, transmitting data to forecasters and scientists. It could therefore help save lives by giving people earlier warnings about potentially deadly storms. In the United States, tornadoes result in hundreds of deaths and billions of dollars in property damage every year. By finding these storms earlier and helping us understand how those storms form in the first place, this sort of research could allow people to get to safety
and batten down the proverbial hatches. Continued work by other teams has shown that infrasound sensor arrays can detect and tracked tornadoes that are over sixty miles or KOs away. Today's episode was written by Christopher Hassiotis and produced by Tyler Klie. For more on this and lots of other
sound topics, visit how stuff works dot com. Brain Stuff is production of I Heart Radio or more podcasts in my heart Radio, visit the I heart Radio app, Apple podcasts, or wherever you listen to your favorite shows.