Ahot plume of mantle material, which may extend to the core-mantle boundary, produces a volcanic region a few hundred kilometers across called a hot spot volcanic arc ring of fire mantle plume

Hot spot

The volcanic hot spot is an area in the mantle from which heat rises as a thermal plume from deep in the Earth.

divide the right side by the left side

0.024÷1.2=0.02 for example

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."