A USGS scientist aims the viewfinder of an infrared spectrometer to measure the chemistry of volcanic gas on the last day of the Nāpau eruption, September 20, 2024. USGS photo by P. Nadeau.
How are volcanic gases measured?
Instruments to measure sulfur dioxide and carbon dioxide can be mounted in aircraft to determine the quantity of gas being emitted on a daily basis. Such instruments can also be used in a ground-based mode. An instrument that detects carbon dioxide can be installed on a volcano and configured to send data continuously via radio to an observatory. Sulfur dioxide in volcanic clouds can also be measured from space with instruments aboard satellites.
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Related
Why is it important to monitor volcanoes?
There are 161 potentially active volcanoes in the United States. According to a 2018 USGS assessment, 57 volcanoes are a high threat or very high threat to public safety. Many of these volcanoes have erupted in the recent past and will erupt again in the foreseeable future. As populations increase, areas near volcanoes are being developed and aviation routes are increasing. As a result, more...
Is it dangerous to work on volcanoes? What precautions do scientists take?
Volcanoes are inherently beautiful places where forces of nature combine to produce awesome events and spectacular landscapes. For volcanologists, they're FUN to work on! Safety is, however, always the primary concern because volcanoes can be dangerous places. USGS scientists try hard to understand the risk inherent in any situation, then train and equip themselves with the tools and support...
How can we tell when a volcano will erupt?
Most volcanoes provide warnings before an eruption. Magmatic eruptions involve the rise of magma toward the surface, which normally generates detectable earthquakes. It can also deform the ground surface and cause anomalous heat flow or changes in the temperature and chemistry of the groundwater and spring waters. Steam-blast eruptions, however, can occur with little or no warning as superheated...
Lava sampling: Why do we do it?
Hot lava samples provide important information about what's going on in a volcano's magma chambers. We know from laboratory experiments that the more magnesium there is in magma, the hotter it is. Chemical analysis, therefore, provides the means not only to determine the crystallization history of lava but also to establish the temperature at which it was erupted. For example, Kilauea's 1997 lavas...
Who monitors volcanic gases emitted by Kīlauea and how is it done?
The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) determines the amount and composition of gases emitted by Kīlauea Volcano. Changes in gas emissions can reveal important clues about the inner workings of a volcano, so they are measured on a regular basis. HVO scientists use both remote and direct sampling techniques to measure compositions and emission rates of gas from Kīlauea...
What gases are emitted by Kīlauea and other active volcanoes?
Ninety-nine percent of the gas molecules emitted during a volcanic eruption are water vapor (H 2O), carbon dioxide (CO 2), and sulfur dioxide (SO 2). The remaining one percent is comprised of small amounts of hydrogen sulfide, carbon monoxide, hydrogen chloride, hydrogen fluoride, and other minor gas species. Learn more: Volcanic gases can be harmful to health, vegetation and infrastructure
Volcanic gas measurements during the 2024 Nāpau eruption
A USGS scientist aims the viewfinder of an infrared spectrometer to measure the chemistry of volcanic gas on the last day of the Nāpau eruption, September 20, 2024. USGS photo by P. Nadeau.
HVO scientist samples volcanic gas from crack—Kīlauea summit, July 22
An HVO scientist samples the gas around a crack identified as emitting elevated levels of carbon dioxide (a volcanic gas) on the down-dropped block within Kīlauea caldera. The sample will later be analyzed to determine its complete chemical composition. This work was conducted within a closed area of Hawai‘i Volcanoes National Park, with park permission.
An HVO scientist samples the gas around a crack identified as emitting elevated levels of carbon dioxide (a volcanic gas) on the down-dropped block within Kīlauea caldera. The sample will later be analyzed to determine its complete chemical composition. This work was conducted within a closed area of Hawai‘i Volcanoes National Park, with park permission.
MultiGAS instruments monitor volcanic gases at the summit
Hawaiian Volcano Observatory field crews establish a new MultiGAS volcanic gas monitoring station on the south side of Kīlauea Volcano's caldera. Currently, sulfur dioxide emission rates from the summit remain low. The station will collect data to track emission rates and concentrations over time. Photo by Frank Younger.
Hawaiian Volcano Observatory field crews establish a new MultiGAS volcanic gas monitoring station on the south side of Kīlauea Volcano's caldera. Currently, sulfur dioxide emission rates from the summit remain low. The station will collect data to track emission rates and concentrations over time. Photo by Frank Younger.
High-tech instruments track volcanic gases at Kīlauea
HVO's geochemist uses a Fourier Transform Infrared Spectrometer (FTIR) instrument to track volcanic gases emitted from the lava lake with Halema‘uma‘u Crater. These measurements help detect changes in gas composition, which can provide insight into the inner workings of Kīlauea Volcano.
HVO's geochemist uses a Fourier Transform Infrared Spectrometer (FTIR) instrument to track volcanic gases emitted from the lava lake with Halema‘uma‘u Crater. These measurements help detect changes in gas composition, which can provide insight into the inner workings of Kīlauea Volcano.
Collecting Gas at a Boiling Pool
USGS geologist Laura Clor (right) and Rachel Teasdale (California State University – Chico, left) collect gas samples from a thermal feature at Sulphur Works in Lassen Volcanic National Park.
USGS geologist Laura Clor (right) and Rachel Teasdale (California State University – Chico, left) collect gas samples from a thermal feature at Sulphur Works in Lassen Volcanic National Park.
Collecting Gas Sample at a Fumarole
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.
Monitoring Volcanic Gases on Kilauea's East Rift Zone II
Hawaiian Volcano Observatory Geochemist Jeff Sutton and CSAV international volcanology students visit a continuous gas monitoring site on Kilauea's east rift zone during field studies portion of the summer training course.
Hawaiian Volcano Observatory Geochemist Jeff Sutton and CSAV international volcanology students visit a continuous gas monitoring site on Kilauea's east rift zone during field studies portion of the summer training course.
Scientists collect volcanic gas data using a Fourier Transform Infrared spectrometer (FTIR)
Scientists collect volcanic gas data using a Fourier Transform Infrared spectrometer (FTIR). During the Kamoamoa eruption, sulfur dioxide emission rates from Kīlauea’s East Rift Zone reached the highest levels since the episodes of high-fountaining at Pu‘u‘ō‘ō (1983–1986) with an average rate of 8,500 tonnes per day and a peak value of 11,000 tonnes per day.
Scientists collect volcanic gas data using a Fourier Transform Infrared spectrometer (FTIR). During the Kamoamoa eruption, sulfur dioxide emission rates from Kīlauea’s East Rift Zone reached the highest levels since the episodes of high-fountaining at Pu‘u‘ō‘ō (1983–1986) with an average rate of 8,500 tonnes per day and a peak value of 11,000 tonnes per day.
Measuring volcanic gases with a Fourier transform infrared (FTIR) s...
Since the opening of the Overlook vent in Halema‘uma‘u Crater in 2008, FTIR spectroscopy has been used to monitor summit eruptive-gas composition. Infrared energy emitted by the lava lake surface (top left) is absorbed by gases present in the path between the instrument and the lak surface.
Since the opening of the Overlook vent in Halema‘uma‘u Crater in 2008, FTIR spectroscopy has been used to monitor summit eruptive-gas composition. Infrared energy emitted by the lava lake surface (top left) is absorbed by gases present in the path between the instrument and the lak surface.
Halema'uma'u Gas Plume Variations (November 17, 2008)
The erupting vent within Halema'uma'u Crater at Kilauea's summit (see http://hvo.wr.usgs.gov/kilauea/timeline/ for links describing eruptive activity at the summit of Kilauea Volcano) typically produces a white to gray gas plume dominated by steam.
The erupting vent within Halema'uma'u Crater at Kilauea's summit (see http://hvo.wr.usgs.gov/kilauea/timeline/ for links describing eruptive activity at the summit of Kilauea Volcano) typically produces a white to gray gas plume dominated by steam.
A gas plume arising from Augustine Volcano during it's eruptive phase 2005-06.
A gas plume arising from Augustine Volcano during it's eruptive phase 2005-06. This photo was taken during a FLIR/maintenance flight on January 24, 2006.
A gas plume arising from Augustine Volcano during it's eruptive phase 2005-06. This photo was taken during a FLIR/maintenance flight on January 24, 2006.
Gas Sampling around the Mount St. Helens Dome
USGS geologists gathered samples by hand from vents on the dome and crater floor. Additionally, sulfur dioxide gas was measured from a specially equipped airplane before, during, and after eruptions to determine "emission rates" for the volcano.
USGS geologists gathered samples by hand from vents on the dome and crater floor. Additionally, sulfur dioxide gas was measured from a specially equipped airplane before, during, and after eruptions to determine "emission rates" for the volcano.
ARRA-funded Student Sampling Gas at Augustine Volcano
ARRA-funded student Taryn Lopez (Univ. Alaska-Fairbanks) sampling gas emissions at fumarole next to dome at the summit of Augustine volcano.
ARRA-funded student Taryn Lopez (Univ. Alaska-Fairbanks) sampling gas emissions at fumarole next to dome at the summit of Augustine volcano.
Halema'uma'u Vent Gas Plume
Kilauea's active summit vent is on the southeast side of Halema'uma'u Crater. In this photo, the floor of Halema'uma'u stretches out beyond the vent, and the summit of Kilauea Volcano is at upper right. The observation tower at the Hawaiian Volcano Observatory is the highest bump in the photo at Kilauea's summit.
Kilauea's active summit vent is on the southeast side of Halema'uma'u Crater. In this photo, the floor of Halema'uma'u stretches out beyond the vent, and the summit of Kilauea Volcano is at upper right. The observation tower at the Hawaiian Volcano Observatory is the highest bump in the photo at Kilauea's summit.
Related
Why is it important to monitor volcanoes?
There are 161 potentially active volcanoes in the United States. According to a 2018 USGS assessment, 57 volcanoes are a high threat or very high threat to public safety. Many of these volcanoes have erupted in the recent past and will erupt again in the foreseeable future. As populations increase, areas near volcanoes are being developed and aviation routes are increasing. As a result, more...
Is it dangerous to work on volcanoes? What precautions do scientists take?
Volcanoes are inherently beautiful places where forces of nature combine to produce awesome events and spectacular landscapes. For volcanologists, they're FUN to work on! Safety is, however, always the primary concern because volcanoes can be dangerous places. USGS scientists try hard to understand the risk inherent in any situation, then train and equip themselves with the tools and support...
How can we tell when a volcano will erupt?
Most volcanoes provide warnings before an eruption. Magmatic eruptions involve the rise of magma toward the surface, which normally generates detectable earthquakes. It can also deform the ground surface and cause anomalous heat flow or changes in the temperature and chemistry of the groundwater and spring waters. Steam-blast eruptions, however, can occur with little or no warning as superheated...
Lava sampling: Why do we do it?
Hot lava samples provide important information about what's going on in a volcano's magma chambers. We know from laboratory experiments that the more magnesium there is in magma, the hotter it is. Chemical analysis, therefore, provides the means not only to determine the crystallization history of lava but also to establish the temperature at which it was erupted. For example, Kilauea's 1997 lavas...
Who monitors volcanic gases emitted by Kīlauea and how is it done?
The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) determines the amount and composition of gases emitted by Kīlauea Volcano. Changes in gas emissions can reveal important clues about the inner workings of a volcano, so they are measured on a regular basis. HVO scientists use both remote and direct sampling techniques to measure compositions and emission rates of gas from Kīlauea...
What gases are emitted by Kīlauea and other active volcanoes?
Ninety-nine percent of the gas molecules emitted during a volcanic eruption are water vapor (H 2O), carbon dioxide (CO 2), and sulfur dioxide (SO 2). The remaining one percent is comprised of small amounts of hydrogen sulfide, carbon monoxide, hydrogen chloride, hydrogen fluoride, and other minor gas species. Learn more: Volcanic gases can be harmful to health, vegetation and infrastructure
Volcanic gas measurements during the 2024 Nāpau eruption
A USGS scientist aims the viewfinder of an infrared spectrometer to measure the chemistry of volcanic gas on the last day of the Nāpau eruption, September 20, 2024. USGS photo by P. Nadeau.
A USGS scientist aims the viewfinder of an infrared spectrometer to measure the chemistry of volcanic gas on the last day of the Nāpau eruption, September 20, 2024. USGS photo by P. Nadeau.
HVO scientist samples volcanic gas from crack—Kīlauea summit, July 22
An HVO scientist samples the gas around a crack identified as emitting elevated levels of carbon dioxide (a volcanic gas) on the down-dropped block within Kīlauea caldera. The sample will later be analyzed to determine its complete chemical composition. This work was conducted within a closed area of Hawai‘i Volcanoes National Park, with park permission.
An HVO scientist samples the gas around a crack identified as emitting elevated levels of carbon dioxide (a volcanic gas) on the down-dropped block within Kīlauea caldera. The sample will later be analyzed to determine its complete chemical composition. This work was conducted within a closed area of Hawai‘i Volcanoes National Park, with park permission.
MultiGAS instruments monitor volcanic gases at the summit
Hawaiian Volcano Observatory field crews establish a new MultiGAS volcanic gas monitoring station on the south side of Kīlauea Volcano's caldera. Currently, sulfur dioxide emission rates from the summit remain low. The station will collect data to track emission rates and concentrations over time. Photo by Frank Younger.
Hawaiian Volcano Observatory field crews establish a new MultiGAS volcanic gas monitoring station on the south side of Kīlauea Volcano's caldera. Currently, sulfur dioxide emission rates from the summit remain low. The station will collect data to track emission rates and concentrations over time. Photo by Frank Younger.
High-tech instruments track volcanic gases at Kīlauea
HVO's geochemist uses a Fourier Transform Infrared Spectrometer (FTIR) instrument to track volcanic gases emitted from the lava lake with Halema‘uma‘u Crater. These measurements help detect changes in gas composition, which can provide insight into the inner workings of Kīlauea Volcano.
HVO's geochemist uses a Fourier Transform Infrared Spectrometer (FTIR) instrument to track volcanic gases emitted from the lava lake with Halema‘uma‘u Crater. These measurements help detect changes in gas composition, which can provide insight into the inner workings of Kīlauea Volcano.
Collecting Gas at a Boiling Pool
USGS geologist Laura Clor (right) and Rachel Teasdale (California State University – Chico, left) collect gas samples from a thermal feature at Sulphur Works in Lassen Volcanic National Park.
USGS geologist Laura Clor (right) and Rachel Teasdale (California State University – Chico, left) collect gas samples from a thermal feature at Sulphur Works in Lassen Volcanic National Park.
Collecting Gas Sample at a Fumarole
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.
Monitoring Volcanic Gases on Kilauea's East Rift Zone II
Hawaiian Volcano Observatory Geochemist Jeff Sutton and CSAV international volcanology students visit a continuous gas monitoring site on Kilauea's east rift zone during field studies portion of the summer training course.
Hawaiian Volcano Observatory Geochemist Jeff Sutton and CSAV international volcanology students visit a continuous gas monitoring site on Kilauea's east rift zone during field studies portion of the summer training course.
Scientists collect volcanic gas data using a Fourier Transform Infrared spectrometer (FTIR)
Scientists collect volcanic gas data using a Fourier Transform Infrared spectrometer (FTIR). During the Kamoamoa eruption, sulfur dioxide emission rates from Kīlauea’s East Rift Zone reached the highest levels since the episodes of high-fountaining at Pu‘u‘ō‘ō (1983–1986) with an average rate of 8,500 tonnes per day and a peak value of 11,000 tonnes per day.
Scientists collect volcanic gas data using a Fourier Transform Infrared spectrometer (FTIR). During the Kamoamoa eruption, sulfur dioxide emission rates from Kīlauea’s East Rift Zone reached the highest levels since the episodes of high-fountaining at Pu‘u‘ō‘ō (1983–1986) with an average rate of 8,500 tonnes per day and a peak value of 11,000 tonnes per day.
Measuring volcanic gases with a Fourier transform infrared (FTIR) s...
Since the opening of the Overlook vent in Halema‘uma‘u Crater in 2008, FTIR spectroscopy has been used to monitor summit eruptive-gas composition. Infrared energy emitted by the lava lake surface (top left) is absorbed by gases present in the path between the instrument and the lak surface.
Since the opening of the Overlook vent in Halema‘uma‘u Crater in 2008, FTIR spectroscopy has been used to monitor summit eruptive-gas composition. Infrared energy emitted by the lava lake surface (top left) is absorbed by gases present in the path between the instrument and the lak surface.
Halema'uma'u Gas Plume Variations (November 17, 2008)
The erupting vent within Halema'uma'u Crater at Kilauea's summit (see http://hvo.wr.usgs.gov/kilauea/timeline/ for links describing eruptive activity at the summit of Kilauea Volcano) typically produces a white to gray gas plume dominated by steam.
The erupting vent within Halema'uma'u Crater at Kilauea's summit (see http://hvo.wr.usgs.gov/kilauea/timeline/ for links describing eruptive activity at the summit of Kilauea Volcano) typically produces a white to gray gas plume dominated by steam.
A gas plume arising from Augustine Volcano during it's eruptive phase 2005-06.
A gas plume arising from Augustine Volcano during it's eruptive phase 2005-06. This photo was taken during a FLIR/maintenance flight on January 24, 2006.
A gas plume arising from Augustine Volcano during it's eruptive phase 2005-06. This photo was taken during a FLIR/maintenance flight on January 24, 2006.
Gas Sampling around the Mount St. Helens Dome
USGS geologists gathered samples by hand from vents on the dome and crater floor. Additionally, sulfur dioxide gas was measured from a specially equipped airplane before, during, and after eruptions to determine "emission rates" for the volcano.
USGS geologists gathered samples by hand from vents on the dome and crater floor. Additionally, sulfur dioxide gas was measured from a specially equipped airplane before, during, and after eruptions to determine "emission rates" for the volcano.
ARRA-funded Student Sampling Gas at Augustine Volcano
ARRA-funded student Taryn Lopez (Univ. Alaska-Fairbanks) sampling gas emissions at fumarole next to dome at the summit of Augustine volcano.
ARRA-funded student Taryn Lopez (Univ. Alaska-Fairbanks) sampling gas emissions at fumarole next to dome at the summit of Augustine volcano.
Halema'uma'u Vent Gas Plume
Kilauea's active summit vent is on the southeast side of Halema'uma'u Crater. In this photo, the floor of Halema'uma'u stretches out beyond the vent, and the summit of Kilauea Volcano is at upper right. The observation tower at the Hawaiian Volcano Observatory is the highest bump in the photo at Kilauea's summit.
Kilauea's active summit vent is on the southeast side of Halema'uma'u Crater. In this photo, the floor of Halema'uma'u stretches out beyond the vent, and the summit of Kilauea Volcano is at upper right. The observation tower at the Hawaiian Volcano Observatory is the highest bump in the photo at Kilauea's summit.
Updated Date: February 28, 2025