Solving an Earth-Sized Jigsaw Puzzle 39
aarondubrow writes "Three years ago, researchers from Caltech and The University of Texas at Austin came together to create a computational tool that could model the Earth and answer the most pressing questions in geophysics: What controls the speed of plates? How do microplates interact? How much energy do the plates generate and how does it dissipate? Using a new geodynamics software package they developed, the researchers have modeled plate motion with greater accuracy than ever before. The project is also a finalist for the Gordon Bell Prize — high performance computing's Oscar — at this year's SC10 conference."
Re:how is this measured? (Score:5, Informative)
You can measure plate motions with GPS, if you're patient. Most of the deep structure is worked out using seismic imaging.
Re:how is this measured? (Score:5, Informative)
Anyone know how the measure this stuff?
Short term (human lifetime) by using GPS, VLBI and measurements of seismic activity.
Long term (earth lifetime) by using magnetic stripe lineations on the seafloor, hot-spot tracks (eg, the Hawaiian volcano chain) and other geologic indicators.
http://en.wikipedia.org/wiki/Plate_reconstruction [wikipedia.org]
Re:how is this measured? (Score:5, Informative)
GPS is the canonical answer here, but not in the form you use in your car or while hiking.
Instead they use the same setup as a surveyor who measures a piece of land:
You have one stationary receiver (the Base station) and one that you move around to measure (the Rover), while a radio link sends information from the base station to the rover.
By observation of the same set of satellites from two points you can lock on to the 1.5 GHz (20 cm wave length) carrier wave, this gives you ~10mm or better resolution within a short time.
For plate tectonics you do the same, but over significantly longer time periods to compensate for the much larger offsets between the two stations.
Before GPS you could do similar stuff with radio telescopes observing pulsars (Very Long Baseline Interferometry), but you still need very carefully synchronized clocks at the two sites, and these days GPS is used for that (i.e. clock sync) as well!
Terje
Re:how is this measured? (Score:4, Informative)