sentence: Geysers are often near active volcanos.
sentences_after: This is because the geyser is caused by magma. Surface water usually goes down to about . There, it mixes with hot rocks. The pressurized water begins to boil. When it is pressured enough, hot water and steam burst out of the geyser.
concept_name: geyser
headings: Geyser Causes
categories: Geology