NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS
Regular VLBI observation in the Keystone Project is terminated
at the end of November, 2001 since the project is time-limited.
We appreciate your kind cooperation. Note that our data base is still
obtainable via internet.
Key Stone Project (KSP)
Key Stone Project (KSP) is the project to monitor regional crustal
deformation in the Tokyo metropolitan area by using three space
geodetic techniques, i.e.
Very Long Baseline Interferometry,
Satellite Laser Ranging,
and Global Positioning System. The project Keystone was named after
the Japanese traditional
saying relating to earthquake prevention.
Kashima-Tateyama Baseline Length (since January 2000)
Since the beginning of July in 2001, the geodetic solution might be
suffered by radio interferences. The data in this period is under
Thank you for your understanding.
Four tectonic plates (North America, Eurasia, Pacific, Philippine Sea)
meet at the Kanto district, causing complicated seismic activity there.
In addition to the Tokai Earthquake (M~8), supposed at the Suruga
Trough and the Odawara Earthquake (M~7), supposed at the western part
of the Kanagawa Prefecture, it has been pointed out that the Tokyo
metropolitan area may suffer from a medium sized earthquake directly
underneath in a near future. Crustal strains have been increasing
since they were reset to zero in 1923 by the great Kanto earthquake
and the earthquake potential is now large enough to cause an
earthquake up to M~7 directly under the Tokyo metropolitan area.
The project to monitor regional crustal deformation in the Tokyo
metropolitan area by using space geodetic techniques has been started
in 1993 by CRL. It is planned that four stations surrounding
Tokyo are equipped with both Very Long Baseline Interferometry (VLBI)
and Satellite Laser Ranging (SLR) fascilities and daily routine
geodetic VLBI/SLR observations are performed in this network to
detect precursory crustal movement that may occur pre-seismically.
These points also provide positional references for the nationwide
network of the Global Positioning System being constructed
by the Geogarphical Survey Institute (GSI), Japan.
[SLR System][GPS System]
[KSP VLBI Stations]
[VLBI Observation Data]
[Related WWW Sites]
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Last Update: June 7, 2006