UNAVCO IDV and Magnetotelluric Data UNAVCO IDV: Magnetotelluric Data

The UNAVCO IDV can display magnetotelluric models (3D grids). Display types include horizontal cross sections with contours and images colored by value, vertical cross sections you can drag, isosurfaces, and vertical probes. Displays can be maps views or in true 3D, with fully interactive rotate and zoom. As always the IDV can combine magnetotelluric model displays with other geoscience data types in the same display.

Sample Displays

Here are static images of interactive IDV displays of the SPRY-MT magnetotelluric model of the Yellowstone - Snake River Plain region.

The magnetotelluric model is that of Kelbert A., Egbert G.D., deGroot-Hedlin C., 2012, Crust and upper mantle electrical conductivity beneath the Yellowstone Hotspot Track: Geology, v. 40, p. 447–450, doi:10.1130/G32655.1.

The data file of the magnetotelluric model was downloaded from the IRIS EMC Earth Models, in particular the SPRY-MT page, which has complete information about this model. Download the NetCDF (.nc) format file, which may be used in the IDV with no format changes.

From the authors:

"A highly conductive (~ 1 S/m) shallow anomaly directly beneath the Yellowstone caldera extends to no more than 20 km depth, but connects to a deeper (40-100 km) conductive feature in the mantle that extends at least 200 km southwest roughly parallel to the direction of North America absolute motion. In several locations beneath the Eastern SRP very high conductivities (a few S/m) are imaged at or near the base of the lower crust." (see http://www.iris.edu/hq/gallery/photo/9390)

Horizontal cross section at 48 km depth of electrical conductivity (units of log(10) electrical conductivity, in S/ma). Click for full size.

Vertical cross sections and isosurface of electrical conductivity (units of log(10) electrical conductivity, in S/ma), in a 3D oblique view from due South. The isosurface has value -1, log base 10 electrical conductivity in S/ma.
The vertical exaggeration is close to 1:1. The IDV display may be rotated and zoomed in all 3D directions to aid in data exploration. Click for full size.

Vertical prodile of electrical conductivity in the model grid cells at and below Old Faithful Geyser (units of log(10) electrical conductivity, in S/ma).