Volcanic Gases Overview

Water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2).

They can cause symptoms ranging from mild eye irritation to severe respiratory difficulties and potential death.

Approximately 3%.

<p>Aerosols are particles formed when certain volcanic gases react with atmospheric components.</p> Signup and view all the answers

<p>The Earth's mantle and the crust.</p> Signup and view all the answers

<p>Volatile substances.</p> Signup and view all the answers

<p>Hydrogen sulfide and carbon monoxide.</p> Signup and view all the answers

<p>Water vapor is the most abundant volcanic gas, typically comprising more than 60% of total emissions.</p> Signup and view all the answers

<p>Acidic corrosion and asphyxiation.</p> Signup and view all the answers

<p>The abundance of volcanic gases varies considerably from volcano to volcano, influenced by volcanic activity and tectonic setting.</p> Signup and view all the answers

<p>Convergent plate boundary volcanoes emit more water vapor and chlorine than those at hot spots or divergent boundaries.</p> Signup and view all the answers

<p>As magma ascends towards the surface, ambient pressure decreases, leading to a decrease in the solubility of the dissolved volatiles.</p> Signup and view all the answers

<p>Halocarbons and mercury are considered exotic trace compounds found in volcanic emissions.</p> Signup and view all the answers

<p>The solubilities of volatile constituents in magma are influenced by pressure, temperature, and the composition of the magma.</p> Signup and view all the answers

<p>Convergent plate boundary volcanoes have higher H2O/H2, H2O/CO2, CO2/He, and N2/He ratios due to their unique geological formation processes.</p> Signup and view all the answers

<p>Carbon dioxide typically accounts for 10 to 40% of volcanic emissions.</p> Signup and view all the answers

<p>The volatiles will exsolve and form a separate gas phase within the magma.</p> Signup and view all the answers

<p>Bubbles grow by expansion through decompression and by additional gas exsolving as solubility decreases.</p> Signup and view all the answers

<p>Higher viscosity may cause bubbles to remain fixed in place, while lower viscosity allows them to rise and coalesce.</p> Signup and view all the answers

<p>Explosive volcanism is driven by the inability of gas to escape, leading to fragmentation of magma into ash.</p> Signup and view all the answers

<p>The type of eruption is determined by the total volatile content of the initial magma and its viscosity.</p> Signup and view all the answers

<p>The fluidised ash has lower resistance to motion compared to viscous magma, causing it to accelerate.</p> Signup and view all the answers

<p>The gas can flow rapidly through a permeable network towards the surface, influencing eruption dynamics.</p> Signup and view all the answers

<p>Small explosions occur when gas bubbles reach the surface and pop, contributing to the eruption's vigor.</p> Signup and view all the answers

<p>Closed system degassing maintains equilibrium between gas and magma, while open system degassing allows gas to escape without remaining in equilibrium.</p> Signup and view all the answers

<p>The gas composition in open system degassing reflects a mass-flow average of the magma exsolved at various depths and is not representative of conditions at any specific depth.</p> Signup and view all the answers

<p>Volcanic gas causes rapid movements of molten rock due to its sudden release, which is a key driving mechanism in explosive eruptions.</p> Signup and view all the answers

<p>When magma meets water, it can lead to rapid fragmentation of the magma, resulting in explosive volcanic activity.</p> Signup and view all the answers

<p>The principal components of volcanic gases include water vapor (H2O), carbon dioxide (CO2), sulfur (as SO2 or H2S), nitrogen, argon, helium, neon, methane, carbon monoxide, and hydrogen.</p> Signup and view all the answers

<p>High-temperature volcanic gases primarily include sulfur dioxide (SO2) and water vapor (H2O).</p> Signup and view all the answers

<p>Latent magmatic heat can cause meteoric water to ascend as a vapour phase, interacting with the hot mixture.</p> Signup and view all the answers

<p>Two low-temperature volcanic gases include hydrogen sulfide (H2S) and water vapor (H2O).</p> Signup and view all the answers

<p>Extended fluid-rock interaction can leach constituents from both the cooling magmatic rock and the country rock, causing changes in volume and ionic strength.</p> Signup and view all the answers

<p>The average carbon dioxide (CO2) emissions from subaerial volcanoes during the period of 2005 to 2017 varied based on volcanic activity but are significant globally.</p> Signup and view all the answers

<p>Cooling can result in phase separation and mineral deposition, leading to shifts toward more reducing conditions.</p> Signup and view all the answers

<p>One compound detected in volcanic gases is hydrogen fluoride (HF), which can be hazardous and contributes to atmospheric pollution.</p> Signup and view all the answers

<p>The upward percolation of the fluid, influenced by interaction with leached materials, typically results in a decrease in the fluid's pH.</p> Signup and view all the answers

<p>Nitrogen (N2) is an inert gas in volcanic emissions and contributes to the overall composition without actively participating in chemical reactions.</p> Signup and view all the answers

<p>Monitoring organic compounds in volcanic gases is significant as they can indicate biological activity and environmental changes associated with volcanic eruptions.</p> Signup and view all the answers

<p>Sulfur hexafluoride (SF6) is a greenhouse gas, and its presence indicates potential impacts on climate change and global warming.</p> Signup and view all the answers