Indeed the feeder pipe almost certainly extends down to a large magma reservoir well below sea level.

The temperature of the magma reservoir below Yellowstone is believed to exceed 800 Celsius causing the heating of rocks in the region.

Both were formed around 20,000 years ago when a rising magma reservoir reached groundwater, creating violent steam explosions.

These volcanic explosions produce vertical columns of rock that rise from deep magma reservoirs.

This melt then moved upward and formed a granitic magma reservoir, possibly about 14 km below the surface.

These lava lakes are directly connected to a magma reservoir lying below.

It'll be hours before we reach the magma reservoir.

"Any significant change in the mantle roofing the magma reservoir, Jim?"

Below, a slowly churning expanse of red represented the magma reservoir.

Also, eruptions may have taken place due to a magma reservoir at the base of the crust.