23. Both shield and composite volcanoes can form features called calderas, a huge crater formed by the collapse of the volcano when magma rapidly erupts from underneath it.
28. Continued Deep –Sea Vents Lower Temperature Mudflows Fumaroles Haze Landslides Geysers Adds to Acid Rain Volcanic Ash Hot Springs Poisonous Gases Lava Water Air Land Materials From Volcanic Eruptions Affect Earth