It helps to predict earthquakes, to understand the origin of things, to understand and predict volcanic activity, to predict where some mineral deposits may be found, to understand prehistoric life; the list goes on...
by using a sonar.
G.P.S. Global Positioning Satellites.
Hot spots are at fixed locations in the Earth's mantle where heat from the Earth's interior rises to the surface and produces volcanism. The Earth's plates, which are slowly but constantly moving, are pierced by the uprising magma. As they move away from the hotspot, the volcanoes become dormant and are replaced by new volcanoes. The direction of the line formed from previous volcanoes indicates the direction of the plate movement.
To keep track of when it may strike next
An environmental scientist studies the different interactions that happen in the environment. Environmental scientists measure the levels of certain elements in the soil and track patterns in the animal interactions.
Scientists want to predict solar winds in Earth's atmosphere to help them track geomagnetic storms. Geomagnetic storms can disrupt the Earth's magnetosphere.
Hot spots can be used to track plate movements.
They can be tracked by satellites.
Yourmoma kk
Because hot spots remain pretty much stationary within the earth, so as the tectonic plates move over them, they create a chain or line of volcanic islands that show the direction the plate has moved over the stationary hotspot.
G.P.S. Global Positioning Satellites.
How do you track it
A seismologist studies the movement of the earth's tectonic plates and, by extension, earthquakes. They use seismographs and other tools to track imperceptible movements that may predict an upcoming seismic event.
Scientists track tornadoes using Doppler radar and reports from eyewitnesses.
Scientists are able to track ozone hole. New technology has enabled them to do so.
Earthquakes, mineral deposits, plate subduction areas/volcanoes, mountains... most anything you can think of is proof really. The above are evidences of plate tectonics. In addition, precise measurements of plate movements have been recorded with scientific instruments that track their speed and direction.
astronomy
you can't for GPS to work you need to be above ground (hundreds of killer meters under-ground)