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2019 Kīlauea Disaster Supplemental Funding: Eruption Response, Monitoring - Gas

Through the Additional Supplemental Appropriations for Disaster Relief Act of 2019 (H.R. 2157), the USGS received Supplemental funding to support recovery and rebuilding activities in the wake of the 2018 Kīlauea volcano eruption. As part of eruption response bolstering, HVO will harden its capability to detect gases from magma and characterize hazards.

Color photograph of two scientists sampling a volcanic fumarole
As part of routine monitoring efforts, HVO gas scientists collected helium samples from fumaroles in the Sulphur Banks, or Ha‘akulamanu, area of Hawai‘i Volcanoes National Park on September 30, 2020. Helium can pass through the glass of typical gas sampling bottles, so copper tubing is necessary for the specialized sample. Ratios of different helium isotopes tell scientists if the source of helium is deeper (from the mantle) or shallower (from the crust). USGS photo by T. Elias.

HVO will restore and harden its network of real-time monitoring instruments at the summit and in critical areas along the rift zones to support early detection of magma movement and more accurate and timely characterization of hazards to Island of Hawai‘i communities and Hawai‘i Volcanoes National Park.  Instruments lost in the eruption will be replaced, other parts of the network will be modernized, and new instruments will be added. Data from a suite of instruments measuring multiple parameters are required to provide the best warnings and forecasts of eruptive activity.  Seismometers, GPS/GNSS, tiltmeters, gas sensors, and gravimeters are needed to assess the state of the volcano.  Thermal and visual camera systems will enable HVO to monitor surface activity at the summit and lower East Rift Zone and neighboring Mauna Loa. HVO will restore and improve its capability to detect gases coming from magma rising into the system. 

Gas Monitoring


HVO scientist samples the gas around a crack identified as emitting elevated levels of carbon dioxide at Kīlauea summit
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. Scientists wore hard hats as they worked in the vicinity of steep caldera walls, and they carried other safety gear such as gas masks and satellite communication devices. USGS image by K. Mulliken, taken on July 22, 2021.

Activity Description/Goal: 

Harden HVO capability to detect gases from magma and characterize hazards. 

Key Successes/Outcomes:

  • Ongoing rehabilitation and upgrading of the Flyspec array (10 stations of upward-looking UV spectrometers).

  • Worked with IT to setup raw data transfer to gas server (vs processed results only); this is a preliminary step in working with Christoph Kern at CVO to upgrade the processing to DOAS (vs FLYSPEC) spectral analysis methodology and possible future conversion of array to portable/reconfigurable vs static/permanent. 4 of 10 stations have new scripts running to transfer raw data; network load is being monitored. Additional stations will have raw data script added pending other station repairs being completed first. 

  • 10 of 10 stations have been outfitted with new UV windows. Previous windows had been damaged/etched by years of high SO2 emissions and significant ash deposition during the 2018 events. A new design for the window fittings is in progress and the window fittings will soon be replaced as well. 

  • 2 of 10 stations converted to onboard single-board computers had preliminary comms/operability testing 

  • Spectrometers were reassessed for ongoing proper function; 1 of 10 spectrometers was determined to have suffered degradation in light sensitivity over time; it was sent to the manufacturer and has been repaired. 

  • 3 of 10 stations have had their initial/aging power supply systems upgraded to modern HVO power setups (“flyaway” power stations), aided by the return of summer gas assistant, Mike Cappos, who was unable to travel during the summer of 2020 due to covid. ~2 additional “flyaway” setups were also built for later use. 

  • 1 other station had its power system repaired (not full “flyaway” upgrade”) and batteries replaced 


A spectrometer used in emission rate traverses and how it reads sulfur dioxide emissions
The left diagram shows how incoming UV would get absorbed by the SO2 plume (faded red arrows) along a spectrometer traverse under the plume (yellow arrow). Under clear sky, no UV is absorbed (blue arrows). Inset is a cartoon diagram of a plume ‘slice’ that the spectrometer measures. At right is the telescope of the UV spectrometer mounted to an HVO vehicle during the 2018 lower East Rift Zone eruption. The telescope is aimed up at the sky, and a fiber optic cable (taped to car window) connects the bottom of the telescope to the spectrometer inside the car. Also visible is a wire attached to a GPS antenna on top of the car. USGS images.