GEOLOGY

Detailed explanation-1: -The crater is the bowl shaped opening located at the top of the volcano. The crater is also the steep sided walls made of hardened lava that surround the main vent. Lava can flow from the main vent, but not all volcanoes eject large amounts of lava.

Detailed explanation-2: -Vents, the openings at the surface where volcanic eruptions occur, and conduits, the channelways that lead from the magma reservoir to the vent, are the only features that all volcanoes have. Some types of volcanoes are exclusively made up of deposits of volcanic ash and other types of tephra.

Detailed explanation-3: -A side vent is an opening in the side of a volcano through which volcanic materials ( lava and gases) erupt.

Detailed explanation-4: -Ninety-nine percent of the gas molecules emitted during a volcanic eruption are water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2).