Mount Etna: Variations in its internal plumbing

Abstract

Abstract. On the basis of historical records of eruptions and the results of recent volcanological, petrological and geophysical investigations, a model for the internal plumbing of Etna is proposed. It is argued that, over about the last 200 years, hawaiite magma has been fed from a deep-seated crustal reservoir at about 20 km depth to be erupted at the surface with no long term high level storage. This is quite a different model for basaltic plumbing from that suggested for Kilauea Volcano on Hawaii. However, the presence on Etna of ignimbrftes, more evolved lavas of mugearite and benmoreite composition, calderas and thick pyroclastic sequences indicates that, at times in the prehistoric past, the style of volcanic activity was different to that of the present. At these times there must have been substantial high level storage of magma in the volcano. It is apparent that the internal plumbing of Etna has varied during the history of the volcano. It is considered that the deep seated crustal reservoir plays an important role in the differentiation of the primitive primary magma.

Laufey Regio: A newly discovered topographic rise on Venus

“…These differences could also reflect changes in flow rates and volumes, and possibly variations in magma composition as suggested for the volcanoes at Dione Regio [Keddie and Head, 1995]. The steeper flanks of the summit cone of Atanua suggest that it has been built by more frequent, shorter effusion flows in a similar way to other large Venusian volcanoes [Stofan et al, 2001] and Mt Etna [Guest and Duncan, 1981;Duncan and Guest, 1982] and the Galapagos volcanoes [Naumann and Geist, 2000] on Earth. The multiple summits of Var Mons may be controlled by pre-existing structure; possible evidence for this is the fractures and graben that cut the eastern and western summits.…”

“…The multiple summits of Var Mons may be controlled by pre‐existing structure; possible evidence for this is the fractures and graben that cut the eastern and western summits. Our observations suggest that Var and Atanua have had a protracted evolution similar to that of terrestrial volcanoes such as Mt Etna in Sicily [ Guest and Duncan , 1981; Duncan and Guest , 1982] and Kilimanjaro in East Africa [ Downie and Wilkinson , 1972].…”

Development of Large Volcanoes on Venus: Constraints from Sif, Gula, and Kunapipi Montes

“…For example, at Mount Etna, eruptions prior to 1669 were more voluminous and petrographically distinct, with large plagioclase phenocrysts indicative of high-level storage (Guest and Duncan 1981, Duncan and Guest 1982). Post 1669 magmas are interpreted to have risen from a chamber 20-25 km below sea level (Sharp et al 1980).…”

Craters, calderas, and hyaloclastites on young Pacific seamounts

“…Specifically, there is strong evidence that summit collapse is probably caused by withdrawal of roof support due to lateral migration of magma outward to feed rift eruptions on Kilauea. Similar processes are thought to be important within Etna [Guest and Skelhorn, 1973;Sharp, 1982;Duncan and Guest, 1982]. On Galapagos volcanoes, which greatly resemble many seamounts in form (upturned soup bowl profile), circumferential fractures are present at the summit in close association with craters and calderas.…”