Persistent CO<sub>2</sub> emissions and hydrothermal unrest following the 2015 earthquake in Nepal.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30054459.
- Also identified by DOI 10.1038/s41467-018-05138-z and PMC identifier 6063904.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Fluid-earthquake interplay, as evidenced by aftershock distributions or earthquake-induced effects on near-surface aquifers, has suggested that earthquakes dynamically affect permeability of the Earth's crust. The connection between the mid-crust and the surface was further supported by instances of carbon dioxide (CO<sub>2</sub>) emissions associated with seismic activity, so far only observed in magmatic context. Here we report spectacular non-volcanic CO<sub>2</sub> emissions and hydrothermal disturbances at the front of the Nepal Himalayas following the deadly 25 April 2015 Gorkha earthquake (moment magnitude M<sub>w</sub> = 7.8). The data show unambiguously the appearance, after the earthquake, sometimes with a delay of several months, of CO<sub>2</sub> emissions at several sites separated by > 10 kilometres, associated with persistent changes in hydrothermal discharges, including a complete cessation. These observations reveal that Himalayan hydrothermal systems are sensitive to co- and post- seismic deformation, leading to non-stationary release of metamorphic CO<sub>2</sub> from active orogens. Possible pre-seismic effects need further confirmation.