Measurement of fugitive methane emissions from an abandoned coal exploration hole in Queensland, Australia using a Quantum Gas LiDAR
Year: 2025
Type: article
Abstract: e. The surveyed borehole, classified as a "super-emitter" (>25 kg/h), exhibited substantial temporal variability in methane flux with the 5th and 95th percentile of 22.8 t/a and 438 t/a, respectively. The survey used a trailer mounted Quantum Gas LiDAR system to enable continuous monitoring over seven days and six nights in variable weather conditions. Exploratory data analysis identified a negative correlation with atmospheric pressure as a likely meteorological driver of emission rate variability, although other factors such as subsurface (groundwater) pressure changes may also influence emission rates. The study highlights that legacy coal exploration infrastructure, if improperly sealed, can act as anthropogenic pathways for uncontrolled methane release. These findings indicate the need for surveys of a larger sample of coal exploration holes across Queensland's coal basins to understand the frequency and rates of emissions, to investigate emissions from other holes, such as water bores, and further investigation of emission dynamics considering geological characteristics and nearby activities. This research indicates the possible significance of legacy coal exploration bores as an under-reported and unaccounted source of methane emissions, with potential implications for coal basins globally.
Authors: Sebastian Hoerning, Philip Hayes
Institution: The University of Queensland
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid: $4,250
Funders: University of Queensland, Arrow Energy
OpenAlex ID: W4411927954