Magnetic-field variation
![plots of wiggly lines](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/intro-geomag.figures.f4.jpg?itok=1v7HdvgS)
Detailed Description
Figure 4. Magnetic-field variation reveals differences in subsurface electrical conductivity. Shown here are magne- tograms taken on 20–21 November 2003 at European ob- servatories of specified longitudes. Horizontal-intensity (H, blue) variation is driven by a storm in the magnetosphere. Site-to-site differences in the downward (Z, red) component are due to induced electric currents in the ocean and crust.
Sources/Usage
Public Domain.