Friday, April 07, 2006

Predicting earthquakes from space by measurement of the Ionosphere

A Russian strategic nuclear-powered submarine is poised to launch an innovative, compact, 80-kg spacecraft from the Barents Sea in the second quarter of this year.
The Compass 2 satellite is expected to help make the first step in the practical forecasting of earthquakes from space.
The move comes as a result of extensive research into specific phenomena in the Earth's magnetosphere and ionosphere, often observed prior to earthquakes, by the Institute of Terrestrial Magnetism, Ionosphere and Radio Waves Propagation (IZMIRAN) of the Russian Academy of Sciences.

The first observations of ionosphere anomalies manifested days before major earthquakes date back to the 1960s. At first, treated no more seriously than UFOs, palm reading and astrology, the findings elbowed their way into the scientific domain in 1979 as the institute launched its Interkosmos 19 satellite. A recording analyzed after one major earthquake showed a prolonged area (narrow in latitude and very broad in longitude) of abnormal, low-frequency noise centered exactly above the earthquake's epicenter several hours before the first shock was felt. Officially registered as a scientific discovery, the phenomenon was later confirmed by findings from other satellites.

This area of research received a powerful push in December 1988 in the wake of a devastating earthquake in Armenia. A pool of Soviet scientific institutions developed a forecasting system that was to be deployed first onboard the Mir orbiter and then across the orbit within a network of unmanned spacecraft. After the Mir, Salyut 6, and Salyut 7 completed the early stages of the plan, the program was effectively buried with the demise of the Soviet Union, but went forward at the end of the turbulent 1990s.

While other precursors of major earthquakes - the concentration of radon, an inert gas, near the epicenter; the concentration of electrons in the ionosphere above the epicenter; and the content of crust-emitted metal-rich aerosols in the air, leading to an abnormally strong electric field there - had been piling up for a long time, they were always obtained as by-products of other research programs. Sufficient statistical data array required a separate specialized satellite. The first international Complex Orbital Magneto-Plasma Autonomous Small Satellite, or Compass, was orbited in December 2001 as a by-load together with the Meteor 3M, a Russian weather satellite, to provide insight into possible links between Earth's crust and magnetosphere behavior. This first field test of an earthquake forecast assessment system largely failed because, while early findings were very promising, the equipment developed jointly by Russia, Hungary, Greece, Ukraine and Poland soon ceased to operate.

Certain progress was made, however, as the data of Compass's launch mate, Meteor 3M, were analyzed by special methods to obtain earthquake precursors. On aggregate, 44 of 47 events registered between October 2002 and May 2003 agreed with data retrieved from land-based seismic records. The generally positive result has led to the upcoming Compass 2 launch and is likely to lead to a follow-up Compass 3 effort. The latter satellite is to be launched in the fourth quarter of 2006 to test more modern and efficient monitoring systems.

On the ground, the Vulkan will include a network of geophysical laboratories, a downlink station and an analysis center. The ground facilities lack the scope and access to recordable events, which explains the need for an orbital component to yield a global survey of seismic activity with accurately timed warnings (one to five days between a precursor and a possible earthquake). All in all, two groups of small satellites are to be deployed at 400-500- and 900-1,000-km solar synchronous orbits.

Researchers from the Institute of the Terrestrial Magnetism, Ionosphere and Radiowave Propagation RAS have observed a chain of interconnected precursors of catastrophic earthquakes in the magnetosphere, geomagnetic field and the Earth’s ionosphere.

They used data from ionosphere observations of the world’s earth-based network of ionosphere stations, which excludes seasonal and daily variations in the state of the ionosphere. It transpired that 10-15 hours prior to an earthquake there are irregularities that arise in the ionosphere – spikes of electronic density (up to 50% of the norm) of 1 to 3 kilometres in length that move horizontally at a rate comparable to the speed of sound. 15-17 hours prior to the underground tremor an electronic spike appears in the magnetosphere.Physicists have proposed a mechanism over which such phenomena take place. Under the “preparation” of a serious earthquake in the Earth’s crust, micro-cracks appear in the region of the future rupture and here an enormous volume of energy is discharged into the atmosphere that exceeds the energy of even a nuclear explosion. A short time before the main tremor radon and other gases, containing elements of radioactive decay, are discharged into the atmosphere from the tectonic depths. The particles start to move in space, while the electromagnetic radiation promotes the penetration of charged particles into the ionosphere. This is where the observed electronic spikes come from.


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