Call this function to return a selected cookie value. After all, it's what causes volcanoes to erupt. Magma results from the extreme heat of the earth's interior. At certain depths, the heat is so great it partly melts the rock inside the earth. When the rock melts, it produces much gas, which becomes mixed with the magma.
Volcanoes are mountains with openings or vents that reach down in the Earth to where magma is found.
Sometimes the heat at the Earth's core or center causes bubbles of carbon dioxide gas in magma to get bigger and expand. This expanding gas pushes magma into the vent of a volcano and up to the surface of the Earth. When a volcano erupts or overflows, from the top of the vent, hot lava flows over its sides. Maybe dad 'blowing his top' isn't so bad after all.