Does anyone have a website which explains the evidence scientists use to determine what is at the center of the earth?

To understand what's deep in the Earth is a great challenge," says geophysicist Lars Stixrude. "Drill holes go down only 12 kilometers, about 0.2 percent of the Earth's radius. Most of the planet is totally inaccessible to direct observation." What scientists have pieced together comes primarily from seismic data. When shock waves from earthquakes ripple through the planet, they are detected by sensitive instruments at many locations on the surface. The record of these vibrations reveals variations in their path and speed to scientists who can then draw inferences about the planet's inner structure


Found HERE

hope this helps


p.s., here is another pretty basic site i found while searching too.

The most amazing thing is that seismic evidence points to the conclusion that the earth's solid crystaline iron core, 3/4 the size of the moon, but because of it's great density, 130% as massive, rotates slightly faster than the earth's surface and mantle.

See: Scientific American.com

---