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INTRO
Introducing the GEON IDV
INSTALL Download & Run the GEON IDV
LEARN
Tutorial
YOUR DATA Data Formats for the IDV |
Using the GEON IDV to Explore Seismic Tomography
print version (black on white)
The GEON IDV is a powerful tool to explore and compare 3D gridded output of seismic tomography, and other geophysical data.
Exploring Tomographic Data
IDV displays are 3D and fully interactive. Once your data is in the IDV, you can make many kinds of displays to bring out 3D structure, and to pinpoint details. You can change your point of view to any angle, and zoom and rotate. You can use the complete color scale control to highlight significant values and boundaries. You can use the IDV's computation facility to compute differences between different tomographic models of the same area.
Displays
The GEON IDV can display gridded model data as isosurfaces (3D surfaces of a data value), or with vertical and horizontal cross-sections, at any depth or position, and with vertical profiles, and single point value probes. Isosurfaces can be colored by other parameters, such as resolution values, so you can judge the precision of the result.
Sample GEON IDV displays of tomography of seismic velocity and velocity anomalies (click on an image to see a larger version):
Vertical cross sections of high resolution seismic velocity tomography under Japan, looking North (Francis Wu et al.)Yellowstone tomography was published in Jordan, M., R.B. Smith and G.P. Waite, 2004. Tomographic images of the Yellowstone hotspot structure, in 2004. Eos, Transactions Amer. Geoph. Un., 2004 Fall Meeting, Suppl. Abst. V51B-0556; and Husen, S., R.B. Smith, and G.P. Waite, 2004, Evidence for gas and magmatic sources beneath the Yellowstone volcanic field from seismic tomographic imaging, Journal of Volcanology and Geothermal Research, Vol. 131 (3-4), p. 397-410
Horizontal cross section, seismic velocity anomalies, with contour lines and, colored by value.
3D oblique view of vertical cross sections, seismic velocity anomalies (colored grid values)
Isosurfaces for two high and low seismic velocity anomalies values, and horizontal cross section at 6 km deep
Isosurfaces for two high and low values, and vertical Cross Sections (colored grid values)
3D Oblique view of Yellowstone region seismic tomography isosurface and vertical cross section, with GPS motion vectors, earthquake focal mechanism beachballs, surface fault lines, and 3D surface relief(transparent).
Side or vertical view of same 3D display, looking North
Comparing Different Processing Runs, and Comparing Different Models' Results
The IDV automatically converts data value units, and automatically uses differing latitude-longitude grids, so that model output from different processing runs or different models' grids can be directly compared with no user conversion work required.
The IDV can do computations with 3d grids, including such things as differences between two models or between a model and a reference data set:
Isosurface and vertical cross section of difference of regional U.S. Vs tomography values (van Der Lee et al.) minus AK135 standard model Vs (click to enlarge)
You can plot model data in any IDV display with any other geophysical data. You can use full globe or regional map (flat) views, and many map projections. You can save displays as images or as movies of time animation or changes in point of view, such as rotations.
The IDV has fully interactive controls for views and time, including vertical scale, zoom, pan, and rotation, and tools to change map projections and background maps, and controls on color tables for data display.
Two or more persons using the IDV can collaborate by sharing "IDV bundle files" which allow you to recreate exactly the same display on your IDV as someone else has made. This is a great way to show what you are doing and do discuss results. If you find something important you can send it to your colleague, and then they will be able to use the full IDV interactivity to investigate the data themselves.
To Install and Run the GEON IDV, and Format Your Data
To install and start the GEON IDV, see Install -- Download & Run the GEON IDV.
To put your data in the NetCDF format the IDV uses: Using the NetCDF data format for seismic tomography
To Explore your Data in the GEON IDV
The best guides for using the GEON IDV are the Tutorial and How to use the GEON IDV.
You need to learn how to load data in the GEON IDV, how to choose and control the geographic area of interest, how to display the data, and how to work with the displays to make the best possible view of the data feature details you are interested in.
