A massive earthquake off Russia's Kamchatka Peninsula in late July triggered a tsunami that rippled across the Pacific — and NASA's experimental detection system tracked the event in real-time by monitoring the atmosphere above.
The GUARDIAN (GNSS Upper Atmospheric Real-time Disaster Information and Alert Network) taps into signals from global navigation satellite systems (GNSS), like GPS. When a tsunami forms, the surge of water pushes on the air above it, sending invisible pressure waves up through the atmosphere. These waves continue rising until they reach the ionosphere — a region high above Earth where satellites send navigation signals down to the ground.
As the pressure waves ripple through the ionosphere, they bend and distort the signals, causing subtle changes that are detectable by GUARDIAN, allowing scientists to detect signs of a tsunami moving across the ocean, before the waves make landfall, according to a statement from NASA's Jet Propulsion Laboratory (JPL).
Source: www.space.com
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