Explosions from composite volcanoes occur as a result of gas buildup within them. Shield volcanoes also may erupt explosively if water accumulates inside their vents.
The data form the earth's magnetic fields that are locked inside the earth's surface below and is thus an understood form seafloor spreading and plate tectonics and occurs at the concepts of the plate tectonics and is thus a valid form the viewpoints form the formation of the earth.
