NASA’s Jet Propulsion Laboratory researchers are exploring the potential of GUARDIAN, an innovative tsunami detection mechanism employing global navigational satellite data. By identifying tsunami-induced ionospheric disruptions, this system could offer a lead time of up to an hour. Currently concentrated on the Pacific Ocean’s Ring of Fire, the researchers aim to broaden the area of coverage and fine-tune the system for automated detection. This cutting-edge hazard-monitoring technology leverages GPS signals for wave tracking in the Pacific Ring of Fire with the goal of enhancing early warning systems in the long run.
Tsunamis, caused by earthquakes, undersea volcanoes, and other Earth movements, can wreak havoc on coastal settlements. Timely alerts are crucial to mitigating their impact. The NASA scientists are testing an unconventional method to detect these lethal waves from the atmosphere’s distant reaches. The experimental surveillance system, GUARDIAN (GNSS Upper Atmospheric Real-time Disaster Information and Alert Network), uses data from GPS and other navigational satellites. Collectively known as global navigational satellite systems (GNSS), these satellites send radio signals to various scientific ground stations globally. These signals are processed by JPL’s Global Differential GPS (GDGPS) network to achieve precise positional accuracy.
The newly developed system searches these signals for evidence of a tsunami. The mechanism relies on the concept that a tsunami causes large oceanic surface areas to elevate and depress almost simultaneously, displacing a substantial volume of the air above. This displaced air expands in all directions as low-frequency sound and gravity waves, eventually reaching the ionosphere – the atmosphere’s topmost layer. The ensuing collision of pressure waves and charged particles may slightly alter the signals from nearby navigational satellites.
Navigation tools usually strive to correct such ionospheric disturbances. However, these disturbances can be used as an essential alert signal, according to Léo Martire, a JPL scientist working on GUARDIAN. Martire stated, “We use this as data to identify natural hazards, instead of correcting it as an error.”
This pioneering technology is still in its development phase but is already one of the quickest tools for monitoring tsunamis. It can create a snapshot of a tsunami’s vibrations reaching the ionosphere within ten minutes, potentially offering an hour’s warning time, depending on the tsunami’s distance from the coast.
The GUARDIAN team envisions it supplementing existing instruments such as seismometers, buoys, and tide gauges, which although highly effective, do not cover the open ocean systematically. Currently, NASA’s Disasters program scientists employ ground-based instruments at GNSS stations for rapid tsunami detection.
The GUARDIAN system presently focuses on the Pacific Ocean’s geologically active Ring of Fire. The region accounted for about 78% of the over 750 confirmed tsunamis between 1900 and 2015. At present, GUARDIAN monitors slightly more than half of this region.
A website is being developed by the GUARDIAN team to allow experts to examine the ionosphere’s state in near real-time through individual satellite station links on the GNSS network. Users can access data from approximately 90 stations around the Pacific Ring of Fire, identifying signals of interest within minutes of an event. The team aspires to widen the coverage and enhance the system to automatically detect tsunamis and other hazards like volcanic eruptions and earthquakes.
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What is NASA’s GUARDIAN?
GUARDIAN is an experimental tsunami detection system currently being tested by scientists at NASA’s Jet Propulsion Laboratory. It utilizes data from global navigational satellite systems, including GPS and other wayfinding satellites, to detect disturbances in the ionosphere caused by tsunamis.
How does the GUARDIAN system work?
GUARDIAN works by detecting disturbances in the ionosphere caused by tsunamis. When a tsunami occurs, it causes a significant displacement of air above the ocean surface. This air expands in the form of low-frequency sound and gravity waves, eventually reaching the ionosphere. The ensuing clash of these waves with charged particles can distort the signals from nearby navigational satellites, and these distortions are what the GUARDIAN system looks for.
How much warning could GUARDIAN potentially provide?
The GUARDIAN system could potentially provide up to an hour’s warning of a tsunami. The actual warning time would depend on the distance of the tsunami origin from the coast.
Where is the GUARDIAN system currently being tested?
Currently, the GUARDIAN system is being tested in the Pacific Ocean’s Ring of Fire. This region is geologically active and accounted for about 78% of the over 750 confirmed tsunamis between 1900 and 2015.
Is the GUARDIAN system fully operational?
As of now, the GUARDIAN technology is still in its development phase. It’s already one of the quickest monitoring tools of its kind, but the scientists at NASA’s Jet Propulsion Laboratory are continuing to refine the system with the aim of automated detection and expanded coverage.
Related links:
- NASA’s official website (https://www.nasa.gov/)
