sentence: Longer ones can take several days to months.
sentences_before: Short eruptions can end in less than a day.
sentences_after: These eruptions begin with clouds of volcanic ash and occasionally pyroclastic flows. Sometimes the amount of magma erupted is so large that the top of the volcano collapses. This leaves a caldera behind. Fine ash can deposit over large areas. Plinian eruptions often happen with loud noises, such as those created by Krakatoa.
concept_name: longer one
headings: Plinian eruption
categories: Volcanology