Science Diary: Volcano – Silence
Ambience: Infrasonic Volcano Emissions (Pele’s Chant)
Garces: It’s one of the loudest things in this whole island. This thing is louder than the ocean, this thing is louder than anything else around it. In terms of human perception, you can stand right by it, and you don’t hear a thing.
A loud sound that you can’t hear? Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Milton Garces monitors volcanic activity by recording low frequency sounds that volcanoes produce: they’re loud, but their frequencies of vibration measured in cycles per second, are so low that humans can’t hear them.
Garces: The most interesting thing and fascinating part about the ongoing eruption is the massive amounts of low frequency sound that are about one cycle every two seconds. This is a very slow process. It’s a really deep volcanic signal.
By recording this signal and speeding up the recording 100 times, the sounds become audible. We’re listening to what’s been nicknamed Pele’s Chant, eruptive activity deep inside Kilauea Volcano. It is heard through a new vent in the Halemaumau crater, which lies within Kilauea, home to Pele, the volcano goddess of ancient Hawaiian legend.
Garces: The way we interpret this Halemaumau signal is that it connects the surface, the atmosphere to a deep chamber, gas at the bottom; when it reaches the atmosphere, it rings on its way up, it’s like listening to a flute that’s embedded inside the volcanic system.
Check out Milton Garces’ blog on Pulseplanet.com. Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation.