Short eruptions can end in less than a day , but longer events can continue for several days or months . The longer eruptions begin with production of clouds of volcanic ash , sometimes with pyroclastic surges . The amount of magma erupted can be so large that it depletes the magma chamber below , causing the top of the volcano to collapse , resulting in a caldera . Fine ash and pulverized pumice can deposit over large areas . Plinian eruptions are often accompanied by loud noises , such as those generated by the 1883 eruption of Krakatoa . The sudden discharge of electrical charges accumulated in the air around the ascending column of volcanic ashes also often causes lightning strikes as depicted by the English geologist George Julius Poulett Scrope in his painting of 1822
1883 eruption of Krakatoa
1883 eruption of Krakatoa
Plinian eruption