# 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 Volcano.

To determine the rate at which sulfur dioxide (SO2) is emitted, HVO scientists measure the amount of ultraviolet (UV) radiation energy absorbed by the volcanic gas plume as sunlight passes through it. They do this by attaching a mini-UV spectrometer (Flyspec) to a field vehicle and driving beneath the plume.

The amount of carbon dioxide (CO2) emitted by Kīlauea is measured using a small infrared analyzer (LI-COR). Scientists drive this instrument through a gas plume, along with the Flyspec, while it continuously and directly samples the ground-level cross-section of the plume.

Another tool used to measure the relative abundance of some gases, including SO2, CO2, hydrogen chloride (HCl), hydrogen fluoride (HF), carbon monoxide (CO) and water vapor (H20), is the Fourier Transform infrared spectrometer (FTIR), which can continuously sample gas in a volcanic plume. The FTIR measures the amount of light absorbed by gases along an open path between the spectrometer and an infrared source, such as an eruptive vent.

## Related Content

Filter Total Items: 11

### Does vog (volcanic smog) impact plants and animals?

The sulfuric acid droplets in vog have the corrosive properties of dilute battery acid. When vog mixes directly with moisture on the leaves of plants it can cause severe chemical burns, which can damage or kill the plants. Sulfur dioxide (SO2) gas can also diffuse through leaves and dissolve to form acidic conditions within plant tissue. Farmers...

### 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 (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2). 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 at our website for Volcanic...

### Where and how do sulfur dioxide and volcanic gases (vog) affect air quality in Hawaii?

The most critical factors that determine how much vog impacts an area are wind direction and speed. Air temperature, humidity, rainfall, location of the source, and the amount of sulfur dioxide (SO2) being emitted are also factors. During prevailing trade (from northeast) wind conditions, any SO2 emitted from Puu Ō ō is blown out to sea, while...

### How much sulfur dioxide (SO2) gas does Kīlauea emit?

Kīlauea typically emits between 500 and 14,000 metric tons of sulfur dioxide gas (SO2) per day during periods of sustained eruption. During the 2018 eruption at Kīlauea’s Lower East Rift Zone, SO2 emissions were over 30,000 metric tons per day, in keeping with the increased vigor of that eruption. Methods for calculating emission rates for SO2 can...

### Should I cancel my plans to visit to Hawaii Island because of sulfur dioxide (SO2) and vog?

Predicting the vog levels that visitors might experience during a short stay in Hawaii is as difficult as predicting the weather. Once volcanic emissions are in the atmosphere, they are distributed by prevailing winds. Where and how bad the vog is ultimately depends on several factors including wind direction, wind speed, air temperature,...

### What health hazards are posed by vog (volcanic smog)?

Vog poses a health hazard by aggravating preexisting respiratory ailments. Sulfur dioxide (SO2) gas can irritate skin and the tissues and mucous membranes of the eyes, nose, and throat, and can penetrate airways, producing respiratory distress in some individuals. Aerosol particles in vog can also penetrate deep into human lungs and, at elevated...

### What is "vog"? How is it related to sulfur dioxide (SO2) emissions?

Vog (volcanic smog) is a visible haze comprised of gas and an aerosol of tiny particles and acidic droplets created when sulfur dioxide (SO2) and other gases emitted from a volcano chemically interact with sunlight and atmospheric oxygen, moisture, and dust. Volcanic gas emissions can pose environmental and health risks to nearby communities. Vog...

### Does ash ever erupt from Kīlauea Volcano??

Kīlauea Volcano is renowned for its relatively benign eruptions of fluid lava flows. Therefore, many people were surprised by the small explosions that occurred in Halemaumau Crater in 2008 and 2018, and even more surprised to learn that volcanic ash was being erupted from a new gas vent. However, ash emissions from Halemaumau Crater are part...

### Why is it important to monitor volcanoes?

The United States and its territories contain 169 geologically active volcanoes, of which 54 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...

### 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...

### What kind of school training do you need to become a volcanologist?

There are many paths to becoming a volcanologist. Most include a college or graduate school education in a scientific or technical field, but the range of specialties is very large. Training in geology, geophysics, geochemistry, biology, biochemistry, mathematics, statistics, engineering, atmospheric science, remote sensing, and related fields can...
Filter Total Items: 5
Date published: May 18, 2017

### EarthWord–Vog

Just like smog and fog, this EarthWord is not what you want to see while driving...

Date published: August 18, 2016

### Living with Vog on an Active Volcano: New Resources

New informational products about the health hazards of volcanic air pollution known as “vog,” are available through a new interagency partnership.

Date published: October 5, 2015

### EarthWord: Fumarole

Fumaroles are openings in the earth’s surface that emit steam and volcanic gases, such as sulfur dioxide and carbon dioxide. They can occur as holes, cracks, or fissures near active volcanoes or in areas where magma has risen into the earth’s crust without erupting. A fumarole can vent for centuries or quickly go extinct, depending on the longevity of its heat source.

Date published: February 11, 2015

### New Study Looks at How People Cope with Vog

A new study to examine how people who live downwind of Kīlauea Volcano cope with volcanic gas emissions, or vog, is currently underway.

Date published: June 20, 2007

### Hazardous Sulfur Dioxide Concentrations Measured at Kilauea Volcano

Today, HVO scientists measured concentrations greater than 10 ppm in a broad area adjacent to Halema‘uma‘u crater. Sulfur Dioxide gas is persistently emitted at Kîlauea's summit. Typical concentrations are generally negligible except for areas downwind of Halema‘uma‘u crater, where they can get up to 2.5 ppm (parts-per-million) in narrow zones.

Filter Total Items: 14
December 31, 2018

### Hovering Above—UAS’ Role in the 2018 Kīlauea Volcano Eruption Response

The 2018 Kīlauea Volcano eruption marked the first time the federal government used Unmanned Aircraft Systems (UAS) to assist in an eruption response in the United States. The UAS were used to survey areas otherwise inaccessible or too hazardous for field crews or manned aircraft, collect multiple types of data, and provide 24/7 real-time situational awareness at Kīlauea

...
August 16, 2016

### USGS HVO geochemist measuring gases released from Kīlauea Volcano

USGS Hawaiian Volcano Observatory geochemist measuring gases released from Kïlauea with a Fourier transform infrared (FTIR) spectrometer, an instrument that detects gas compositions on the basis of absorbed infrared light. The data obtained from FTIR measurements have been useful in identifying the many components of volcanic-gas emissions, which provide information on the

...
August 16, 2016

### Gas plume from Halemaʻumaʻu Crater, Kilauea Volcano

With stagnant winds present, the plume from Halemaumau Crater at the summit of Kilauea Volcano, stands straight up, showing off the distant, but bright, full moon.

July 8, 2016

### Taking Lava Temps

In this photo, a USGS researcher is taking a temperature measurement on a sluggish channel eddy on Kīlauea Volcano in 1984. The research in Hawaiʻi is just one of many projects overseen by the USGS Volcano Hazards Program, which monitors active and potentially active volcanoes, assesses their hazards, responds to volcanic crises, and

...
April 27, 2016

### A USGS geologist collects a molten lava sample during a December 2015 lava flow from Puʻu ʻŌʻō.

A USGS geologist collects a molten lava sample during a December 2015 lava flow from Puʻu ʻŌʻō. As the lava cools on the surface, its viscosity increases and the flow slows down. Credit: USGS.

May 31, 2014

### 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. Instrumentation at this site measures ambient concentration of noxious sulfur dioxide gas released from the volcano's vents, along with

...
May 31, 2014

### Monitoring Volcanic Gases on Kilauea's East Rift Zone

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. Instrumentation at this site measures ambient concentration of noxious sulfur dioxide gas released from the volcano's vents, along with meteorological

...
June 3, 2010

### Deploying a FTIR on Pu’u ‘Ō’ō crater

This photo was taken from the lamp on the other side of the plume. The FTIR is the small dark silhouette on the rim across the crater gap.

August 30, 2018

### PubTalk 8/2018 — What on Earth is going on at Kilauea Volcano?

Title: What on Earth is going on at Kilauea Volcano?

• First significant summit explosions in nearly a century
• Largest summit collapse volume since at least 1800
• Voluminous fissure eruptions feeding channelized lava flow
• Unparalleled new opportunities for understanding the volcanic system
June 3, 2010

### Deploying a FTIR on Pu’u ‘Ō’ō crater

HVO gas geochemists deployed a FTIR spectrometer on the east rim of Puu Ō ō crater. The FTIR measures the composition of the East Wall vent gases by "looking" through the plume at an infrared lamp (obscured by fume in this photo)