This map shows tectonic plate movement over a "hot spot" that created Craters of the Moon National Wilderness. Hot spots are stationary and as the North American Plate moved Southwest over the hot spot, a trail of volcanism was left in its wake. The hot spot is now located in Yellowstone National Park. So, understanding hot spots in relation to tectonic plate movement can help people understand volcanism as well as provide a technique for mapping the movement of Earth's tectonic plates.

via www.mnh.si.edu