Volcanic Gases

volcanic gases

[väl′kan·ik ′gas·əz]
Volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen, released during an eruption of a volcano.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Volcanic Gases


gases formed during and after an eruption from a crater, crevices on the sides of volcanoes, and lava flows and pyroclastic rock. The gases emitted during a crater eruption are called eruptive gases, and all others, which are emitted during periods of quiet volcanic activity in the form of streams and swirling masses (from various sections of the crater or from the surface of lava flows), are called fumarole gases.

Eruptive gases determine the character of explosive eruptions and influence the flow of molten lava. These gases contain vapors of H2O, H2 HCl, HF, H2S, CO, and CO2 and small amounts of volatile compounds, mainly halogen compounds of many elements. Fumarole gases are mixtures of gases emitted from lava or pyroclastic rock with gases captured from the atmosphere, formed as a result of their reaction with organic substances found under the hot lava flows or the pyroclastic deposits.

Volcanic gases form numerous hot springs as they pass through the zone of underground waters.


Basharina, L. A. “Vulkanicheskie gazy na razlichnykh stadiiakh aktivnosti vulkanov.” In the collection Tr. laboratorii vulkanologii AN SSSR, issue 19. Moscow, 1961.
Iwasaki, I. [et al.]. “Nature of Volcanic Gases and Volcanic Eruption.” Bulletin Volcanologique, 1963, vol. 26.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
"The speed of magma rise and storage is tightly linked to the transfer of heat and chemicals in the crust of volcanic regions, which is important for geothermal power and the release of volcanic gases to the atmosphere."
The public meanwhile is reminded that the main crater should be strictly off-limits because sudden steam explosions can occur and high concentrations of toxic volcanic gases can be released.
The image shows a vast plume of ash and volcanic gases shooting up from the Raikoke Volcano's 700-metre-wide crater, at around 4am on June 22, 2019.
He said that signs of an impending eruption would include intensive earthquakes, deformation of the terrain, rapid accumulations of volcanic gases, and rising surface temperatures in excess of averages.
Tsunamis caused by volcanoes can be triggered by submarine explosions or by large pyroclastic flowsaa hot mix of volcanic gases, ash and blocks traveling at tens of miles per houraif they enter in a body of water.
Greenhouse gases exhaled during the eruptions that spawned the Medusae Fossae could have warmed Mars's surface enough for water to remain liquid at its surface, but toxic volcanic gases like hydrogen sulfide and sulfur dioxide would have altered the chemistry of Mars's surface and atmosphere.
The fast-moving flows overtook people in homes and streets with temperatures reaching as high as 1,300 degrees, as well as hot ash and volcanic gases that can cause rapid asphyxiation.
Lava illuminates volcanic gases from the Kilauea volcano on Hawaii's Big Island on Pahoa, Hawaii.
"No mask sold in stores provides protection from the extremely dangerous volcanic gases that are being released from the current volcanic eruption," the spokesperson said.
Residents of a second area, Lanipuna Gardens, were barred from returning home on Monday due to deadly volcanic gases.