Measurements at the Mauna Loa Observatory stopped after the 2022 eruption of the Mauna Loa volcano, when lava flow crossed the access road and took out power lines to the facility. The observatory remains inaccessible by vehicle and without power from the local utility company.

Observatory staff has established limited solar power in four observatory buildings and restored approximately 33 percent of the measurements onsite, including the Global Monitoring Laboratory and Scripps critical CO2 records and other atmospheric measurements.

Media can contact: Theo Stein (303) 819-7409 ( or Karin Vergoth 303-632-6413‬ (

Q: When did MLO begin?

A: The MLO slope building was constructed in 1956, and MLO attained full operational status during the International Geophysical Year (IGY) of 1957. It began continuous atmospheric carbon dioxide (CO2) measurements in 1958.

Q: How high is the observatory?

A: The observatory altitude is 3397m (11,140ft). For more information, click here.

Q: Why is Mauna Loa Observatory such an ideal place to sample the atmosphere?

A: The observatory is located on an island in the middle of the Pacific ocean, away from major air pollution sources. MLO also protrudes through the strong marine temperature inversion layer present in the region. This inversion layer acts like a lid and keeps the lower local pollutants below the observatory.

Q: Does Kilauea volcano affect the measurements?

A: As mentioned above, the inversion layer keeps the vog below the observatory. During conditons when the inversion layer is weak or nonexistant, the sulfur dioxide affects some of the instruments sensors. Dust particles(aerosols) affect the solar radiation measurements.

Q: How long has the Keeling analyzer been running?

A: The original instrument (which ran on vacuum tubes) was put into operation in 1958 and has run continously since. In 2006 the original instrument was replaced with a newer solid state one. For more information on this program, click here.