Slashdot Mirror
Solving an Earth-Sized Jigsaw Puzzle
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."
You can measure plate motions with GPS, if you're patient. Most of the deep structure is worked out using seismic imaging.
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
You can measure plate motions with GPS, if you're patient. Most of the deep structure is worked out using seismic imaging.
You don't have to be really patient... plates move at 2-10 cm/year so you'd start getting GPS data within 2-5 years, Historic data is not too hard to get as the Magnetic stripe patterns on the spreading seafloor give data going back to the Jurassic and the mechanical/geological fit between continents gives data on the original configuration
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
"almost all programming can be viewed as an exercise in caching"
Is there any reason, if people will SILL live in California despite anything you can dig out?
Setting aside parser errors I suppose California is only dangerous if you choose to live under an unstable pile of rocks.
http://michaelsmith.id.au
You don't even have to be that patient. With a GPS fiducial network you could be getting results in months rather than years.
Does this work in practice? As I understand it a GPS fiducial network uses ground bases transmitters which would move along with the plate which at the very least would complicate the data analysis...
A large proportion of the worlds population live in earthquake or volcano zones ... ...Because that is where all the richest soils, and mineral deposits are ...
Most large cities are on the coast or on large rivers and so are prone to flooding, because they grew due to being a port
Very few cities are founded where it is safe, instead they are founded where resources are, which also turn out to be dangerous ....
People continue to live there because that's where the work is ...
Puteulanus fenestra mortis
Sorry, I must have mistyped the html on the link.
Quidnam Latine loqui modo coepi?
These sorts of models are great because you run the model, and then see which parts of the earth don't fit in real life. You can then investigate that area more closely and either refine the model, or refine your understanding of that particular region.
I'm a geologist and most of my undergrad and graduate studies were on tectonics. What they've got here is fantastic and will yield a lot of great new research and discoveries about plate interactions. It's basically an extension of what people have been doing for decades (modeling and comparing models to reality where possible), so the idea is really not new, but the implementation is fantastic.
So at first it should be fairly clunky, and if you run the model as you suggest going through all of earth's history, yes it will be wrong. But if you take it step-by-step based on what's already understood about past tectonic plate positions (which is quite a lot), i.e. constraining the model, it should be able to show us all kinds of new things and ultimately a complete run-through should be possible that's very accurate. They will be able to continually refine it, of course, as new research comes out, and have a fairly complete model of plate evolution based on whatever the currently accepted progression is.
Ah now you've uncovered the truth about the Theory of Natural Earthquakes. The whole field of geophysics is running a big scam, made to funnel money into the earthquake prediction business, give politicians more power over how we construct our buildings, and assure these "scientists" get more grant money!
Earthquakes are actually caused almost entirely by the weight of buildings placed on tectonic plates. It changes the friction between the plates, causing them to slip.
Did you ever notice that whenever an earthquake happens, buildings are under construction? Coincidence? I think not. Do you think tsunamis happen because of eathquakes? An alternative theory is that ship wakes eventually grow into tsunamis, which then trigger earthquakes. There is a lot of controversy over this. Of course nature does play some role, but it's greatly overstated. The earthquake predictions made by these "scientists" are wildly inaccurate, and it's quite safe to ignore these warnings. Anyone with some common sense can understand this.
Preparing for an earthquake will only damage the economy. Besides I'm sure in the future our descendants will find a way to go back in time and prevent earthquakes from happening, so it would be premature to take any action now. Don't let these doomsayers scare you.
"When information is power, privacy is freedom" - Jah-Wren Ryel