Lava Dome

A lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusionof viscous lava from a volcano. The geochemistry of lava domes can vary from basalt to rhyolite although most preserved domes tend to have high silica content.[1] The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite.

How lava domes form? Lava domes are formed by viscous magma being erupted effusively onto the surface and then piling up around the vent . Like lava flows, they typically do not have enough gas or pressure to erupt explosively, although they may sometimes be preceded or followed by explosive activity.

Where can we find it?

Lava domes can form anywhere associated with volcanic activity. They are commonly found within the crater of large composite volcanoes, such as Mount St. Helens, but are not limited to this location. They also often occur on the flanks ofvolcanoes.

What it is made of?

Lava domes take on a variety of textures, but are often blocky in nature. A block ofdacite lava. Dacite lava can frequently be found creating lava domes due to its relatively viscous nature. Occasionally, even obsidian (Rhyolite Glass) will be erupted and can form lava domes, such as Glass Mountain in California.

What is the size of it?

The shape and size of lava domes varies greatly, but they are typically steep-sided and thick. The thickness can range anywhere from a few meters to nearly one kilometer in height. The diameter or length of these domes can range from a few meters to many kilometers.

5 most popular Dome Volcano in the world

1.Lassen Peak-Lassen Peak,[3] commonly referred to as Mount Lassen, is the southernmost active volcano in the Cascade Rangeof the Western United States. Located in the Shasta Cascade region of Northern California, Lassen stands 3,500 ft (1,100 m) above the surrounding terrain and has a volume of 0.5 cu mi (2 km3), making it one of the largest lava domes on Earth.[4] It arose on the destroyed northeastern flank of now-gone Mount Tehama, a stratovolcano at least 1,000 ft (300 m) higher than Lassen Peak. It is part of the Cascade Volcanic Arc, which stretches from southwestern British Columbia to northern California.

2.Mount Tarumae-is located in the Shikotsu-Toya National Park in Hokkaidō, Japan. It is located near both Tomakomai and Chitose towns and can be seen clearly from both. It is on the shores of Lake Shikotsu, a caldera lake. Tarumae is a 1,041 metre active andesitic stratovolcano, with a lava dome.

3.Novarupta-in Latin) is a volcano that was formed in 1912, located on the Alaska Peninsula in Katmai National Park and Preserve, about 290 miles (470 km) southwest of Anchorage. Formed during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of magma of the 1980 eruption of Mount St. Helens.

4.Puy de Dôme-is a large lava dome and one of the youngest volcanoes in the Chaîne des Puys region of Massif Central in central France. This chain of volcanoes including numerous cinder cones, lava domes, and maars is far from the edge of any tectonic plate. Puy de Dôme is approximately 10 kilometres (6 mi) from Clermont-Ferrand. The Puy-de-Dôme département (with hyphens) is named after the volcano.

5.Black Butte-is a cluster of overlapping dacite lava domes in a butte,[2] a parasitic satellite cone of Mount Shasta.[5] It is located directly adjacent to Interstate 5 at milepost 742 between the city of Mount Shasta and Weed, California. The highway crosses a 3,912 ft (1,192 m) pass, Black Butte Summit, at the western base of the lava domes. The lava domes were extruded at the foot of the cone of Shastina following the period of its major eruptions about 9,000–10,000 years ago

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the last eruption of Mt. St. Helens in California,USA