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Posted on 09/15/2010 9:10:23 PM PDT by neverdem
Progress of waves through open sea sends vibrations that magnify with height up the entire atmospheric column.
The signals of GPS satellites could be used to monitor tsunamis as they sweep across the ocean. In the most detailed study to date of the effect, scientists have shown that even though open ocean tsunami waves are only a few centimetres high, they are powerful enough to create atmospheric vibrations extending all the way to the ionosphere, 300 kilometres up in the atmosphere.
The finding, the researchers hope, could hugely improve tsunami early-warning systems.
In a study published online on 1 September in Geophysical Research Letters1, a team of French geophysicists was able to use these ionospheric effects to trace the progress of three recent tsunamis, including the one triggered by the 27 February earthquake in Chile, which had a magnitude of 8.8. The researchers showed that the strength of the ionospheric effects increased with the height of the wave.
The maximum height of that tsunami, which swept across the Pacific, was only 10 centimetres in mid-ocean, but low-lying tsunami waves can be more than 100 kilometres long. During a tsunami, hundreds of square kilometres of ocean rise and fall, nearly in unison. This produces a rhythmic movement in the atmosphere, generating a vertically propagating wave known as an internal gravity wave. The thinning air causes the wave to spread out vertically and the air movements become larger.
"At around 300–350 kilometres of altitude, the atmospheric wave has been amplified by a factor of 10,000 or more," says Lucie Rolland, a graduate student at the Paris Institute of Geophysics, whose PhD work spearheaded the study. "This means that a 10-centimetre tsunami wave at ocean level will induce atmospheric displacement reaching 1 kilometre."
Fluctuating signals
Rolland says that the collision of this wave...
(Excerpt) Read more at nature.com ...
Strange. I never remembered tsunami waves as being such a problem before — was it just one time in the last hundred years?
So the satellites that we need to monitor this huge problem will cost how many hundreds of billions of dollars?
Isn’t this money urgently needed in Africa for more programs to determine if washing is effective? So many programs, so hard to choose...
I suspect amateur radio enthusiasts will be all over this... if somewhat embarassedly because after all these years of skip communications they never figured this out.
The whole thing smells like bovine scat.
Hurricanes and cyclones have immense influence on atmospheric pressure, and also are responsible for raising and lowering the surface of the oceans in large swells.
This sounds like another excuse to suck some milk off the federal teat.
Conclusion: de-fund the department that suggests this study for each time they request stuff like this.
Yeah but with sunspots going away, pretty much won't matter.
Sounds like a mass equivalence thing. The mass of 100 kilometers of ocean X thousand feet deep being lifted 10 centimeters equals some function times the mass of the atmosphere above it... going way, way above it, because the atmosphere is so much less dense than the water.
Biggest loudspeaker ever.
The 40m band was all messed up yestereay. Extremely noisy with lots of ionospheric doppler which reaks havok on psk’ers, but with sporadic dx windows that came and went within minutes.
"The signals of GPS satellites could be used to monitor tsunamis as they sweep across the ocean."
They were paid for a while ago.
LOL - and what again were they teaching people to wash?
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