MANAGING MAGMA:
Tracking Volcanic Activity With Thermal Imaging
Automated thermal monitoring and optical gas imaging help volcanic observatories prepare for eruptions and recover from the aftermath
By Jo Fischer
Few tasks seem as mountainous as monitoring volcanic activity: fumes or smoke can obstruct views, hot volcanic material may not be incandescent enough to be seen in daylight, and eruption can leave behind dangerous risks in its aftermath. But in recent years, thermal imaging for volcano monitoring has become a critical technology for observatories—and Flir has proven its cameras can stand up to the heat. Whether employing a fixed Flir thermal camera for lava monitoring or an optical gas imaging (OGI) camera to detect carbon dioxide emissions, observatories have the end-to-end solutions they need to address both heat signatures and invisible gases.
A Flir science camera capturing minor activity inside of a volcanic crater
The Case for Thermal
While eruptions may be rare, studying and tracking thermally active volcanic areas is essential for detecting precursory signals of volcanic unrest. Volcano observatories conduct routine thermal surveys to analyze changes in thermal patterns across fumaroles, hydrothermal systems, open vents, and fractures—key inputs for eruption prediction tools.
The primary goal of these surveys is to understand the trigger mechanism of unrest in active volcanic areas that are usually affected by hydrothermal circulation.
Through fixed continuous thermal monitoring, observatories can maintain their observation and data collection around volcanic areas. Because these cameras visualize heat and not light, they face little issue in collecting a clear view of volcanic material and can easily discern hot, warm, and cool surfaces—no matter the lighting conditions. They can sometimes even see through fumes.
Surface temperature information is critical as it can signal to observers which surfaces have been recently active, or inactive.
Kīlauea Summit, looking at the Halemaʻumaʻu crater and lava lake from the western rim.
Getting the Bigger Picture
With the right lens, thermal cameras can sufficiently cover the wide views needed for monitoring large open spaces. A Flir A70 thermal camera fitted with a 95° lens, for example, can provide the wide angle needed to monitor large, outdoor volcanic areas. The camera can also measure temperatures up to 1000°C (1832°F) with an accuracy of ±2%; even at a great distance from potential targets, this camera can provide observers with a “ballpark” range of useful information. Flexible Scene Enhancement (FSX®) increases image contrast, improving visibility through smoke. When configured for Image Streaming, the A70 can stream compressed radiometric images and visual images together over Wi-Fi, with access from a standard web browser.
From the Field
Hawaiʻi Volcanoes National Park is home to Kilauea, one of the world’s most active volcano sites which has been intermittently erupting within the summit since December 2024. The U.S. Geological Survey (USGS) provides live thermal image updates of the Halemaʻumaʻu lava lake there with a Flir A655sc high-resolution science grade camera. This longwave thermal camera is paired with a 45° horizontal field of view lens and housed in a custom enclosure made from a Pelican case for protection. Hourly thermal images from the past 24 hours can be found on their website, showcasing how Flir thermal cameras underpin modern volcano observatory technology for real‑time situational awareness.
Thermal cameras have demonstrated their utility during volcanic events as well, gathering crucial information for researchers. For example, during the 2007 Stromboli eruption, observers used thermal imaging to monitor lava flow branches extending down the Sciara del Fuoco, noting progression and identifying when branches began cooling. The thermal imaging provided valuable inputs for on‑the‑ground eruption monitoring solutions and post‑event assessments.
Cleaning Up Invisible Threats
In addition to hot lava, volcanic incidents have another, more difficult-to-notice danger in the form of invisible gases. After the 2021 Cumbre Vieja volcano eruption in La Palma, the island was left grappling with invisible carbon dioxide (CO₂) emissions. In volcanic areas such as La Palma, CO₂ can collect unnoticed in depressions and poorly ventilated spaces, displacing oxygen and creating life-threatening situations for both local communities and scientists on the ground.
Recognizing the need for a more advanced monitoring solution, the National Geographic Institute (Instituto Geográfico Nacional - IGN) adopted the Flir G343 Optical Gas Imaging (OGI) camera, provided by Apliter Termografía, to strengthen its volcanic surveillance efforts.
The Flir G343 is a specialized thermal imaging camera built for gas detection that provides faster decisions, better protection, and more efficient scientific monitoring. While traditional detection methods require air sampling and lab analysis, the G343 visualizes gas leaks in real time, right in the field.
IGN researchers immediately saw the difference. During field tests, they witnessed firsthand how the Flir G343 could pinpoint dangerous CO₂ hotspots, helping them work safer and more efficiently in post-eruption environments.
Detection of gas in areas of La Palma using an OGI camera. Source: Apliter Termografía
The Deputy Director of IGN and the Commercial Director of Apliter showcasing the Flir G343.
While volcanic events may be rare, their effects can be devastating and long lasting. As shown though, many of the mentioned challenges can be dealt with through continuous thermal monitoring and optical gas imaging. Advanced thermal technology will continue to be crucial in enabling observatories and geological professionals to understand activity, predict future events, and respond to the aftermath left behind.
