London: Scientists have for the first time captured the atmospheric signature of tsunami, which they claim could soon lead to an effective early warning system for the phenomenon.
A team, led by the University of Illinois, captured the airglow signature of the tsunami that struck the Japanese coast on March 11 using an observatory on island of Hawaii,
the `Daily Mail` reported.
It was found at a height of 250 km above the Earth`s surface and preceded the giant wave striking the coast by around an hour. Airglow is the greenish layer of light that is found when molecules combine after being split by sunlight.
The discovery, published in the `Geophysical Research Letters` journal, suggested that tsunamis could be observed in the upper atmosphere, but till now this was only demonstrated by using radio signals.
The research focused on the fact that tsunamis generate atmospheric gravity waves as they travel across the ocean. These waves have the potential to stretch several kilometres into the sky causing changes that can be imaged due to decreases in air density.
After making the images, the University of Illinois team, led by Jonathan Makela, joined forces with teams in France, Brazil and at a New York University to perform a detailed analysis.
They found the wave properties matched those from a ocean-level tsunami, confirming the signature originated from the Japanese tsunami.
Prof Makela now believes that camera systems could be developed to create an early warning system. He said that a reliable system could be some way off as scientists need to develop algorithms to analyse and filter data in real time.
"This is a reminder of how interconnected our environment is. This technique provides a powerful new tool to study the coupling of the ocean and atmosphere and how tsunamis propagate across the open ocean," he added.