Wednesday, May 18, 2011
MIT's Technology Review notes today:
Geologists have long puzzled over anecdotal reports of strange atmospheric phenomena in the days before big earthquakes. But good data to back up these stories has been hard to come by.
In recent years, however, various teams have set up atmospheric monitoring stations in earthquake zones and a number of satellites are capable of sending back data about the state of the upper atmosphere and the ionosphere during an earthquake.
Last year, we looked at some fascinating data from the DEMETER spacecraft showing a significant increase in ultra-low frequency radio signals before the magnitude 7 Haiti earthquake in January 2010
Today, Dimitar Ouzounov at the NASA Goddard Space Flight Centre in Maryland and a few buddies present the data from the Great Tohoku earthquake which devastated Japan on 11 March. Their results, although preliminary, are eye-opening.
They say that before the M9 earthquake, the total electron content of the ionosphere increased dramatically over the epicentre, reaching a maximum three days before the quake struck.
At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake. In other words, the atmosphere was heating up.
These kinds of observations are consistent with an idea called the Lithosphere-Atmosphere-Ionosphere Coupling mechanism. The thinking is that in the days before an earthquake, the great stresses in a fault as it is about to give cause the releases large amounts of radon.
The radioactivity from this gas ionises the air on a large scale and this has a number of knock on effects. Since water molecules are attracted to ions in the air, ionisation triggers the large scale condensation of water.
But the process of condensation also releases heat and it is this that causes infrared emissions. "Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data," say Ouzounov and co.
These emissions go on to effect the ionosphere and its total electron content.
The BBC pointed out in 2008:
Nasa scientists have said they could be on the verge of a breakthrough in their efforts to forecast earthquakes.
Researchers say they have found a close link between electrical disturbances on the edge of our atmosphere and impending quakes on the ground below.
Just such a signal was spotted in the days leading up to the recent devastating event in China.
They have teamed up with experts in the UK to investigate a possible space-based early warning system.
Many in the scientific community remain deeply sceptical about whether such signals are indeed indicators of an approaching earthquake.But Minoru Freund, a physicist and director for advanced aerospace materials and devices at Nasa's Ames Research Center in California, told BBC News: "I do believe that we will be able to establish a clear correlation between certain earthquakes and certain pre-earthquake signals, in an unbiased way."
The ionosphere is distinguished from other layers of Earth's atmosphere because it is electrically charged through exposure to solar radiation.
On a significant number of occasions, satellites have picked up disturbances in this part of the atmosphere 100-600km above areas that have later been hit by earthquakes.
One of the most important of these is a fluctuation in the density of electrons and other electrically-charged particles in the ionosphere.
One study looked at over 100 earthquakes with magnitudes of 5.0 or larger in Taiwan over several decades. The researchers found that almost all of the earthquakes down to a depth of about 35km were preceded by distinct electrical disturbances in the ionosphere.The analysis was carried out by Jann-Yeng Liu, from the Center for Space and Remote Sensing Research in Chung-Li, Taiwan.
Though full details have yet to be released, the BBC understands that scientists also observed a "huge" signal in the ionosphere before the Magnitude 7.8 earthquake in China on 12 May.
Minoru and his father Friedemann Freund, also from Nasa Ames Research Center, developed the scientific theory behind these earthquake precursors. It boils down to the idea that when rocks are compressed - as when tectonic plates shift - they act like batteries, producing electric currents.
"We now pretty much understand the solid-state physics of these rocks," Minoru added.
According to their theory, the charge carrier is a "positive hole", known as a phole, which can travel large distances in laboratory experiments.
When they travel to the surface of the Earth, the surface becomes positively charged. And this charge can be strong enough to affect the ionosphere, causing the disturbances documented by satellites.
When these pholes "recombine" at the surface of the Earth, they enter an excited state. They subsequently "de-excite" and emit mid-infrared light particles, or photons. This may explain the IR observations.
Some Allege High Tech Warfare
Many claim that the strange atmospheric effects preceding earthquakes must prove that this is caused by high-tech warfare.
They point, for example, to the fact that humans have modified weather for military purposes and climate control for decades.
Alter the climate, set off earthquakes, volcanoes remotely through the use of electromagnetic waves.They point to the statement of top Russian politician Vladimir Zhirinovsky - Vice-Chairman of the Russian State Duma and leader of the Liberal Democratic Party of Russia - who supposedly said that Russia possesses "secret" weapons that can cause tsunamis like the March tsunami which devastated Japan:
But This Has Been Happening for Thousands of Years
A contrary argument, however, is that strange atmospheric phenomena have been observed for thousands of years ... long before any high technology was invented.
As I noted last year:
Strange lighting phenomenon has been observed in connection with earthquakes throughout history.
For example, "immense columns of flame" were reported by Greek writings prior to the giant earthquake in 373 BC in which destroyed the cities of Helike and Bura.
And the New England Earthquake of 1727 was preceded by strange lighting phenomena:
People that were awake when the earthquake came said that a flash of light preceded it. It was seen as it passed the windows, and a blaze seemed to run along the ground, dogs that saw it giving a sudden bark as if frightened. Before they had time to consider the source or cause of the light a sound like a gentle murmur floated to them on the still evening air, followed by a slight ruffling wind. Then came a rumbling as of distant thunder, which approached nearer and nearer and grew louder and louder till it sounded as if innumerable heavy carriages were being rapidly driven over pavements, or like the roaring of a great furnace, but incomparably fiercer and more terrible, having a hollow sound as if it came from under the earth. Then the shock came suddenly and severely and the houses were felt to totter and reel with the trembling and heaving of the ground.See this and this. [Strange blue lights also appeared during the huge Japanese earthquake on March 11th, and strange colors appeared before the 2008 Chinese earthquake.]
There are numerous theories about the cause of "earthquake lights", including:
- Sparks or gas ionisation due to a piezoelectric effect in quartz-bearing rock
- Frictional heating
- Exoelectron emissions
- Generation and ignition of flammable gases either from pockets of natural gas or from rocks under enormous stress.
- Gas ionisation or electrical effects due to electrokinetics
- Separation of positive hole charge carriers that turn rocks momentarily into p-type semiconductors
Another Mechanism?There is another possible explanation.
Mitch Battros theorized in 1998 that large solar flares affect Earth's magnetic field, which in turn shifts the oceanic and atmospheric currents, which can cause earthquakes and extreme weather. As Battros summarizes his formula:
Sunspots => Solar Flares (charged particles) => Magnetic Field Shift => Shifting Ocean and Jet Stream Currents => Extreme Weather and Human DisruptionWhile this may sound crazy, Battros' theories have been endorsed to one degree or another by:
- Dr. Ernest Hildner, Director NOAA Space Weather Center
- Dr. Tom Van Flandern, former US Naval Observatory Chief of Celestial Mechanics
- Dr. Stefaan Poedts: Lead Scientist University of Leuven Center for Plasma Astrophysics
- Dr. Ronald van der Linden, Director of Solar Physics Department of the Royal Observatory
- Dr. Pål Brekke, Deputy Director of SOHO project- European Space Agency
The stakes are enormous. And it is vital to fund research into cause and effect interactions between atmosphere and earthquake faults.
The sun itself also affects the Earth more than previously understood. For example, according to the European Space Agency:
And NASA has just discovered that "space weather" causes "spacequakes" on Earth:Scientists ... have proven that sounds generated deep inside the Sun cause the Earth to shake and vibrate in sympathy. They have found that Earth’s magnetic field, atmosphere and terrestrial systems, all take part in this cosmic sing-along.Researchers using NASA's fleet of five THEMIS spacecraft have discovered a form of space weather that packs the punch of an earthquake and plays a key role in sparking bright Northern Lights. They call it "the spacequake."
A spacequake is a temblor in Earth's magnetic field. It is felt most strongly in Earth orbit, but is not exclusive to space. The effects can reach all the way down to the surface of Earth itself.
"Magnetic reverberations have been detected at ground stations all around the globe, much like seismic detectors measure a large earthquake," says THEMIS principal investigator Vassilis Angelopoulos of UCLA.It's an apt analogy because "the total energy in a spacequake can rival that of a magnitude 5 or 6 earthquake," according to Evgeny Panov of the Space Research Institute in Austria.
"Now we know," says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "Plasma jets trigger spacequakes."
According to THEMIS, the jets crash into the geomagnetic field some 30,000 km above Earth's equator. The impact sets off a rebounding process, in which the incoming plasma actually bounces up and down on the reverberating magnetic field. Researchers call it "repetitive flow rebuffing." It's akin to a tennis ball bouncing up and down on a carpeted floor. The first bounce is a big one, followed by bounces of decreasing amplitude as energy is dissipated in the carpet.
"When plasma jets hit the inner magnetosphere, vortices with opposite sense of rotation appear and reappear on either side of the plasma jet," explains Rumi Nakamura of the Space Research Institute in Austria, a co-author of the study. "We believe the vortices can generate substantial electrical currents in the near-Earth environment."
Acting together, vortices and spacequakes could have a noticeable effect on Earth. The tails of vortices may funnel particles into Earth's atmosphere, sparking auroras and making waves of ionization that disturb radio communications and GPS. By tugging on surface magnetic fields, spacequakes generate currents in the very ground we walk on. Ground current surges can have profound consequences, in extreme cases bringing down power grids over a wide area.
What does this mean?
Some allege that spacequakes cause actual, physical earthquakes on Earth. I have no idea whether or not that is true.
The above-quoted NASA article concludes with a poem which implies such a connection:
a magnitude six
However, the poem may use artistic license rather than scientific rigor.
If we can forecast earthquakes through measuring solar radiation (as Battros believes) or heat, radon and fracture stress (as many mainstream scientists believe), we can finally formulate an early-warning system for earthquakes.