Archive for the ‘Geology’ Category

Crowdsourcing for Seismic Surveys

Every weekday afternoon around 5pm or so, the quarry several miles from my house blasts away a new layer of limestone. Whenever I feel the slight tremor from the blast, I feel as if valuable data is going uncollected. Could this data somehow be used to make a 3D model of the Edwards Aquifer?

An overlooked aspect of a GPS receiver is the highly accurate clock it contains. It seems like GPS receivers (and their clocks) could be attached to low-cost seismometers. The common clock of the GPS would allow independently collected data to be synthesized. I wonder if there might be enough geo-geeks in my neighborhood to build and deploy an array of these. There’s another quarry about 10 miles away, where I presume they also blast, so not all blasting signals originate from the same location. There will also soon be a lot of highway construction starting in this area, which will likely involve yet more blasting. Once the data is collected, it could be forwarded to a central site for processing. With all the recent innovations in oil exploration seismic processing, it seems like this data could be continually synthesized for model refinement. I’m not a seismologist, but would be interested in hearing from one regarding the plausibility of this.

While the geologists over at Edwards Aquifer Authority have done an fine job, it would be nice if they could build some detailed 3D models and serve them out on the web.
Edwards aquifer

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OpenGL for AGX … did I just feel the earth move?

As Location Based Soup points out, the latest AGX build has some cool stuff. At first glance it looks like support for OpenGL in the new build of ArcGIS Explorer could make for interesting plate tectonic tools.

plate tectonics

Particularly, it seems like a list of rotation steps for different plates could be played back through time (where each has a different pole of rotation). Perhaps quaternions would make adding up the rotational vectors easier, here’s a tutorial that might help with the math.

Animations like these would be more interesting in AGX.

Plate Tectonics in ArcGlobe?

I’m surprised Chris Scotese hasn’t ported his plate tectonic modeling applications to ArcGlobe.

Long ago (well, not that long geologically speaking) I worked on integration of ARC/INFO with a plate tectonics modeling package. Plate movement through time is described as a sequence of rotations about a pole. These movements are inferred from geologic field work that is constantly being refined, or at least updated. The math gets really hairy, but it seems like internally ArcGlobe has to perform these calculations anyway. If ESRI were to expose a method that allows a polygon to be rotated about an arbitrary pole a specified number of radians, then porting a plate tectonic app would be a lot easier. Even better would be if I could take a sequence of rotations and sum them all up to a single rotation.