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Subscribe to RSSThe earthquake and tsunami that left almost 19,000 people dead and displaced hundreds of thousands more was remembered with moments of silence and prayer. NBC's Brian Williams reports.
By Becky Oskin
LiveScience
Earthquakes rattle the ground, vibrating Earth's surface like the skin of a drum and sending low-frequency sound waves into the sky.
The tremendous shaking from Japan's Tohoku earthquake in 2011, the fourth-biggest temblor on record, was so powerful the sound traveled into space, a new study reports.
The acoustic waves, called infrasound, jiggled the European Space Agency's GOCE satellite, which measures tiny variations in Earth's gravity field. The satellite was designed to maintain an ultra-stable orbit by automatically adjusting for such variations. Researchers used a computer model to analyze and extract the satellite's response to the infrasound waves and compute their frequency.
The satellite tracked the acoustic waves twice, passing through the atmospheric disturbance over the Pacific Ocean about 30 minutes after the quake and over Europe at about an hour later. The GOCE satellite was 140 miles (225 kilometers) above Earth. This is the first time a satellite has directly recorded infrasound in space, the European Space Agency said in a statement. The findings will appear in an upcoming issue of the journal Geophysical Research Letters. [See how the satellite tracked the infrasound.]
"Seismologists are particularly excited by this discovery because they were virtually the only Earth scientists without a space-based instrument directly comparable to those deployed on the ground," Raphael Garcia, lead study author, said in a statement. "With this new tool, they can start to look up into space to understand what is going on under their feet," said Garcia, a physicist with the Research Institute in Astrophysics and Planetology in France.
ESA / IRAP / CNES / TU Delft / HTG / Planetary Visions
Japan's Tohoku earthquake in 2011 was felt by the GOCE satellite.
For decades, ground-based and underwater infrasound detectors have tracked the deep resonance for research and for the Comprehensive Nuclear-Test-Ban Treaty Organization. Earthquakes, bomb explosions and even meteors shattering in the sky can send acoustic ripples through the atmosphere.The Tohoku earthquake's sound waves were also recorded by ground-based infrasound networks.
The magnitude-9.0 Tohoku earthquake, which struck two years ago today, was also powerful enough to slightly alter Earth's gravity field under Japan.
Email Becky Oskin or follow her @beckyoskin. Follow us @OAPlanet, Facebook or Google+. Original article on LiveScience's OurAmazingPlanet.
- Video: See & Hear the Japan Earthquake
- 7 Craziest Ways Japan's Earthquake Affected Earth
- Infographic: How Japan's 2011 Earthquake Happened
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but in space, no one can hear you scream
It is interesting that even at that altitude there were enough air molecules available and in close enough proximity to transmit the wave. There appears to be some connection between all molecules of matter that allows a wave pattern response to generate no matter the distance between the molecules.
See, that's what I don't understand. At 99 miles above earth is the anacoustic zone where the density is so low that molecular interactions are too infrequent to permit the transmission of sound. I don't understand how a 20hz wave could propagate at 140 miles above the earth, where oxygen molecules can travel half a mile without interaction. Just doesn't seem possible.
Maybe it is mislabeled and should be a gravitational wave or more simply it was puff of expelled air.
From reading the article, it seems that what was detected was the tiny change in the gravity field due to the density variation in the atmosphere below several minutes after the quake ... pretty remarkable, and the first time I've heard of such a detection. If it was due to the shifting of mass within the earth, it would have been much sooner after the quake. Of course once some mass has moved around, the "gravitational wave" itself travels at the speed of light per Einstein, and so would introduce almost no additional delay in this case.
Eric, your analysis sounds the best.
Changes in the mass at the Earth's surface at the time of the event would have been measured long before the acoustic signature would reach the satellite, but the longitudinal waves in the atmosphere following the event would cause changes in gravity acceleration measured at the satellite.
The article is either incorrect or too vague, in my opinion.
An altitude at which a satellite would have a stable orbit would not have sufficient gas density to transmit sound--I think.
The report is confused, but it does say early on that the satellite was responding to variations in Earth's gravitational field, not to sound waves. The report then goes on about variations in atmospheric pressure variations being "heard" in space,etc., which completely confuses the real story.
Lousy science reporting, as usual nowadays, whatever the publication.
Nothing was "heard" as far out as the satellite. Its orbit varied slightly in response to gravitational changes caused by tremors. That is very interesting by itself and offers scientists another way of measuring how our planet behaves. Quite enough without dressing it up in science fiction.
siegfried - lousy science reporting so true. And the problem lies with us - as consumers of the news we do not demand that they get it right, in fact most consumers (and I will qualify that I am not referring to those who have taken the time to read and comment here) expect to have the science news dumbed down. And I bet we would all agree that it needs to be dumbed down because a) schools do a pi$$ poor job of teaching science; b) polticians and the religious fundamentalists seem to feel that they have the right to say what is true and not true in science; c) many people are too lazy to try and understnad science.
Now I think I'll go find and article on the God Particle and see what discord I can spread. :)
This is good science reporting. How come it took this long for scientists, or science reporters, to get to this? The quake was two years ago! Does it take this long for the data to be processed, or is it that the technology to detect this kind of infrasound in space is new...hence requires time to carefully understand and verify?
It took so long because the data did not jump up and say, "Here I am!" They may have noted anomalous readings, but that does not give them a reason for them.
Scientists are also cautious people, they can't afford to make claims they cannot back up with data. They might have developed the theory fairly early, but it takes time to run down other possibilities (equipment failure, radiation effects on circuits, etc.) before they will make an announcement.
What about the time when the Apollo 13 spacecraft had that explosion on the way to the moon? They certainly heard that noise. So, don't tell me there can't be any sounds heard when you are in outer space.
Well, inside the spacecraft they heard it (because there was air inside), and they likely felt the vibrations too.
I have to challenge the terminology used in the article.
Sound (acoustic waves, however low frequency) cannot be transmitted across a vacuum (space), and that is essentially what the article wants you to believe.
But, the infrasound can flex the Earth's mantle such that a measurable change in gravitational acceleration can be read reflecting the effect of the infrasound.
Again, what I understand is that the density variation in the atmosphere (not in the mantle) was detected gravitationally, which would be possible even if the wave stopped at the "top" of the atmosphere below the orbit of the satellite.
This is God's punishment on Japan when human fails to. Japan is again trying get sympathy from other countries. But they never talk about and even denies war atrocities they committed to this day. Very recently, the PM of Japan Shinzo Abe visited the war shrine to honor Class A WWII war criminals. And he said it was ok that Japan colonized Korea, and that the slavement of Korean women as sex slaves was ok. And he even whitewashed their war crimes in textbooks. Before Pearl Harbour, from the advanced of Shanghai to Nanking, the Imperial Japanese Army murdered 300,000 civilians and disarmed soldiers. Girls, children and even pregnant women were not spared, they were raped and killed, Japan committed horrible atrocities. Unlike Germany, they deny what they did and never compensate the victims. Can you imagine Merkel honoring Hitler??? Morality cannot be legislated, but GOD's he will do what humans can't at the moment!!!!
And here come the religious wackos trying to say a horrific earthquake was the work of God. If it was then God is one sadistic bastard not worthy of anyone's worship.
Robert, friend, please do not claim to understand the mind of God or the reasons for His alleged actions or why He allows things to happen. For any human to claim to understand God, and why natural things happen expresses not only arrogance, but idolatry as well.
In my freshman year of majoring in Physics, the Physics professor told us on the first day of class that "not all scientists are atheists, and we get to have a closer look at the handiwork of the Almighty."
Please don't embarrass those of us who choose to believe yet still believe the validity of science, and who--don't let this scare you---believe in evolution and other "heresies."
inMYday - hey did you have the same physics professor I did?
The earthquake was so powerful it spilled all the Big Gulp drinks in NYC, parted Donald Trump's hair, made Kim Jon-Un's belly jiggle, and activated the methane gas of Uranus.
... Excuse me, there is no air or sound in outer space! This headline is nonsense.