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Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. [1]
Active volcanoes such as Stromboli, Mount Etna and Kīlauea do not appear on this list, but some back-arc basin volcanoes that generated calderas do appear. Some dangerous volcanoes in "populated areas" appear many times: Santorini six times, and Yellowstone hotspot 21 times.
When the volcano is extinct, a plug forms on its vent, over time due to erosion, the volcanic cone slowly erodes away leaving the resistant lava plug intact. [2] Cinder Hill , a feature of Mount Bird on Ross Island , Antarctica , is a prominent example of a dissected volcano.
A volcanologist is a geologist who studies the eruptive activity and formation of volcanoes and their current and historic eruptions. Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra (such as ash or pumice), rock and lava samples. One major focus of ...
Volcanoes known to have subglacial activity include: Mauna Kea in tropical Hawaii. There is evidence of past subglacial eruptive activity on the volcano in the form of a subglacial deposit on its summit. The eruptions originated about 10,000 years ago, during the last ice age, when the summit of Mauna Kea was covered in ice. [60]
The Hawaiian shield volcanoes are not located near any plate boundaries; the volcanic activity of this island chain is distributed by the movement of the oceanic plate over an upwelling of magma known as a hotspot. Over millions of years, the tectonic movement that moves continents also creates long volcanic trails across the seafloor.
MANILA (Reuters) -The alert level has been raised at a volcano in the central Philippines after it erupted, sending a 5-kilometre (3.1-miles) high ash cloud into the sky, the country's seismology ...
World map of active volcanoes and plate boundaries Kīlauea's lava entering the sea Lava flows at Holuhraun, Iceland, September 2014. An active volcano is a volcano that has erupted during the Holocene (the current geologic epoch that began approximately 11,700 years ago), is currently erupting, or has the potential to erupt in the future. [1]