Plinian eruptions eject columns ofvolcanic debris andhot gases high into thestratosphere, the second layer of Earth's atmosphere. They eject a large amount ofpumice and have powerful, continuous gas-driven eruptions.
Eruptions can end in less than a day, or continue for days or months. The longer eruptions begin with production of clouds of volcanic ash, sometimes withpyroclastic surges. The amount ofmagma ejected can be so large that it depletes the magma chamber below, causing the top of the volcano to collapse, resulting in acaldera. Fine ash and pulverized pumice can be deposited over large areas. Plinian eruptions are often accompanied by loud sounds. The sudden discharge of electrical charges accumulated in the air around the ascending column of volcanic ashes also often causeslightning strikes, as depicted by the English geologistGeorge Julius Poulett Scrope in his painting of 1822 or observed during2022 Hunga Tonga–Hunga Ha'apai eruption and tsunami.[2]
The lava is usuallydacitic orrhyolitic, rich in silica.Basaltic, low-silica lavas rarely produce Plinian eruptions unless specific conditions are met (low magma water content <2%, moderate temperature, and rapid crystallization);[3] a recent basaltic example is the1886 eruption of Mount Tarawera on New Zealand'sNorth Island.[4]
On August 24th, about one in the afternoon, my mother desired him to observe a cloud which appeared of a very unusual size and shape. He had just taken a turn in the sun and, after bathing himself in cold water, and making a light luncheon, gone back to his books: he immediately arose and went out upon a rising ground from whence he might get a better sight of this very uncommon appearance. A cloud, from which mountain was uncertain, at this distance (but it was found afterwards to come from Mount Vesuvius), was ascending, the appearance of which I cannot give you a more exact description of than by likening it to that of a pine tree, for it shot up to a great height in the form of a very tall trunk, which spread itself out at the top into a sort of branches; occasioned, I imagine, either by a sudden gust of air that impelled it, the force of which decreased as it advanced upwards, or the cloud itself being pressed back again by its own weight, expanded in the manner I have mentioned; it appeared sometimes bright and sometimes dark and spotted, according as it was either more or less impregnated with earth and cinders. This phenomenon seemed to a man of such learning and research as my uncle extraordinary and worth further looking into.
— Sixth Book of Letters, Letter 16, translation byWilliam Melmoth
Pliny the Elder set out to rescue the victims from their perilous position on the shore of theBay of Naples, and launched hisgalleys, crossing the bay toStabiae (near the modern town of Castellammare di Stabia). Pliny the Younger provided an account of his death, and suggested that he collapsed and died through inhaling poisonous gases emitted from the volcano. His body was found buried under the ashes of the eruption with no apparent injuries on 26 August, after the plume had dispersed, which would be consistent with asphyxiation or poisoning, but also with a heart attack, asthma attack, or stroke.
April 21, 1990, eruption cloud fromRedoubt Volcano as viewed to the west from the Kenai Peninsula (more than 60 km from the volcano's summit)April 2015, subplinian eruption ofCalbuco
In 1980, the volcanologistGeorge P. L. Walker proposed theHatepe eruption as the representative of a new class called ultra-Plinian deposits, based on its exceptional dispersive power and eruptive column height.[8] Adispersal index of 50,000 square kilometres (19,000 sq mi) has been proposed as a cutoff for an ultra-Plinian eruption.[8] In the criteria ofVolcanic Explosivity Index, recognizing an eruption as ultra-Plinian would make it at least VEI-5.[9]
The once unequivocal ultra-Plinian classification of the Hatepe eruption has been called into question, with recent evidence showing that it is an artifact of an unrecognized shift in the wind field rather than extreme eruptive vigor.[16][17]
^Enlightenment activities for improvement on disasters.From 23–27 January 2006 Tarumae volcano [eruption], Japan, 4 cities near volcanoes.[full citation needed]
^Williams, Stanley N.; Self, Stephen (1983). "The October 1902 plinian eruption of Santa Maria volcano, Guatemala".Journal of Volcanology and Geothermal Research.16 (1–2):33–56.Bibcode:1983JVGR...16...33W.doi:10.1016/0377-0273(83)90083-5.
^Vidal, Céline M.; Komorowski, Jean-Christophe; Métrich, Nicole; Pratomo, Indyo; Kartadinata, Nugraha; Prambada, Oktory; Michel, Agnès; Carazzo, Guillaume; Lavigne, Franck; Rodysill, Jessica; Fontijn, Karen; Surono (2015-08-08). "Dynamics of the major plinian eruption of Samalas in 1257 A.D. (Lombok, Indonesia)".Bulletin of Volcanology.77 (9): 73.Bibcode:2015BVol...77...73V.doi:10.1007/s00445-015-0960-9.ISSN1432-0819.
^Scarpati, Claudio; Perrotta, Annamaria (2016-03-09). "Stratigraphy and physical parameters of the Plinian phase of the Campanian Ignimbrite eruption".Geological Society of America Bulletin.128 (7–8):1147–1159.Bibcode:2016GSAB..128.1147S.doi:10.1130/b31331.1.ISSN0016-7606.
^Self, Stephen; Wolff, John ; Wright, John (2021-12). Tsankawi Pumice Fall Unit B, a Very Widespread and Powerfully Emplaced Plinian Deposit.AGU Fall Meeting 2021.
