Monitoring volcanic gas tells the story of magma and groundwater movement
The thermal areas of Yellowstone discharge a lot of gas through geysers, mud pots, hot pools, and fumaroles. The chemical makeup of these gases provides USGS scientists clues to what is happening in the hydrothermal and volcanic systems beneath the surface.
Research on the chemistry of Yellowstone's gas emissions is driven by a need to better understand and monitor both the deep magmatic system and the overlying hydrothermal system. This research shows there are 3 primary sources of gas at Yellowstone: the deep magmatic system; shallower crustal (rock-related) sources; and the atmosphere. The gas that ultimately discharges at the surface may contain components from all of these sources.
Most of the gas emitted from Yellowstone's thermal features is steam (boiling water), which is often visible, especially on a cold morning.The remaining gas is primarily carbon dioxide (typically > 90%) with minor additions of helium, hydrogen sulfide, nitrogen, oxygen, methane, ammonia and other trace gases.
Studies of gas emissions are further complicated by the fact that some gas components are found in more than one source. For example, helium and carbon dioxide are emitted by magma at all volcanoes, but can also be released from rocks in the crust under the influence of heat. One method to tease out the difference is to determine the isotopic composition of some gas components, which can tell the story about gas origins.
Studies of gases at Yellowstone are expanding rapidly as new methods are developed for long-term measurements of steam, carbon dioxide and hydrogen sulfide. Typically, gas samples are collected sporadically, perhaps once per year. One of the first quasi-continuous gas sensors was installed near Norris Geyser Basin during the summer of 2016, and in the summer of 2017 the equipment was placed on the Central Plateau. There are plans to install Yellowstone's first continuously operating (year-round) gas sensor at Norris.
The thermal areas of Yellowstone discharge a lot of gas through geysers, mud pots, hot pools, and fumaroles. The chemical makeup of these gases provides USGS scientists clues to what is happening in the hydrothermal and volcanic systems beneath the surface.
Research on the chemistry of Yellowstone's gas emissions is driven by a need to better understand and monitor both the deep magmatic system and the overlying hydrothermal system. This research shows there are 3 primary sources of gas at Yellowstone: the deep magmatic system; shallower crustal (rock-related) sources; and the atmosphere. The gas that ultimately discharges at the surface may contain components from all of these sources.
Most of the gas emitted from Yellowstone's thermal features is steam (boiling water), which is often visible, especially on a cold morning.The remaining gas is primarily carbon dioxide (typically > 90%) with minor additions of helium, hydrogen sulfide, nitrogen, oxygen, methane, ammonia and other trace gases.
Studies of gas emissions are further complicated by the fact that some gas components are found in more than one source. For example, helium and carbon dioxide are emitted by magma at all volcanoes, but can also be released from rocks in the crust under the influence of heat. One method to tease out the difference is to determine the isotopic composition of some gas components, which can tell the story about gas origins.
Studies of gases at Yellowstone are expanding rapidly as new methods are developed for long-term measurements of steam, carbon dioxide and hydrogen sulfide. Typically, gas samples are collected sporadically, perhaps once per year. One of the first quasi-continuous gas sensors was installed near Norris Geyser Basin during the summer of 2016, and in the summer of 2017 the equipment was placed on the Central Plateau. There are plans to install Yellowstone's first continuously operating (year-round) gas sensor at Norris.