Drone approaching the Otmanbozdagh mud volcano three days after the eruption. The new eruption site from 11 October 2025 is visible as a dark area in the center of the image.
As part of the International Methane Emissions Observatory (IMEO), an initiative of the United Nations Environment Programme (UNEP), a team from the DLR Institute of Atmospheric Physics (DLR-IPA), together with local and international partners, has carried out drone-based measurements of methane emissions from mud volcanoes in Azerbaijan. The aim of the project is to better quantify these still poorly understood geological methane sources and to compare their emissions with those from other, mainly anthropogenic, sources. Azerbaijan hosts around 300 of the approximately 1000 known mud volcanoes worldwide. These natural features vary significantly in their activity: some emit gas continuously, while others remain dormant for long periods before erupting explosively for short durations.
In preparation for the measurements, a fixed-wing drone operated by the local partner Olimp UAV LLCwas equipped with scientific instrumentation, including high-precision in-situ methane and wind sensors. Olimp UAV LLC, who have extensive experience in operating unmanned aerial vehicles (UAVs) in Azerbaijan, carry out the scientific flight operations within the project. The DLR-IPA team developed and optimized a measurement strategy adjusted to the specific conditions of Azerbaijan’s mud volcanoes, enabling reliable airborne quantification of methane emissions. The first successful measurement flights took place in spring 2025 in the presence of the DLR-IPA team. Based on these initial missions, a standardized measurement protocol was established, allowing the partners to independently continue the flights in close scientific coordination with DLR. The measurement concept is based on Gauss’s divergence theorem: the drone flies on concentric circles at different altitudes around the mud volcano. Methane fluxes are derived from upwind and downwind measurements, enabling the quantification of the total emission enclosed by the cylindrical flight pattern. In October, DLR scientists returned to Azerbaijan to carry out an experiment validating the flight strategy by releasing and measuring methane under controlled conditions.
This project is supported by partners from the Institute of Geology and Geophysics of the Ministry of Science and Education of Azerbaijan, as well as from the Italian National Institute of Geophysics and Volcanology, who contribute their expertise in geodynamic and volcanic processes.
On 11 October 2025 at 08:27 local time, the Otmanbozdagh mud volcano erupted explosively. It is one of the largest mud volcanoes in the world and is located about 40 kilometres south of Baku. The sudden natural release of methane resulted in a towering flame above the crater. The team quickly obtained the necessary permits and was able to conduct ground-based measurements at the crater on 13 October, followed by drone flights over the eruption site on 14 and 19 October. Preliminary analyses show that increased methane concentrations were still detected several days after the eruption, up to 200 metres above ground and more than one kilometre from the crater.
The collected data provide the first high-resolution in-situ methane measurements following a mud volcano eruption. Together with ongoing observations at active and continuously emitting mud volcanoes, these results will contribute to a more accurate quantification and assessment of the role of geological methane sources in the global climate system.
Contact
Dr. Anke Roiger
Abteilungsleiterin
Institut für Physik der Atmosphäre
Atmosphärische Spurenstoffe
Münchener Straße 20, 82234 Oberpfaffenhofen-Wessling
Dr Manuel Moser
German Aerospace Center (DLR)
Institute of Atmospheric Physics
Atmospheric Trace Species
Münchner Straße 20, 82234 Oberpfaffenhofen-Wessling
