Options
2-D tomography of volcanic CO<sub>2</sub> from scanning hard-target differential absorption lidar: the case of Solfatara, Campi Flegrei (Italy)
Language
English
Obiettivo Specifico
4V. Dinamica dei processi pre-eruttivi
Status
Published
JCR Journal
JCR Journal
Title of the book
Issue/vol(year)
/9 (2016)
Pages (printed)
5721–5734
Issued date
2016
Abstract
Solfatara is part of the active volcanic zone of
Campi Flegrei (Italy), a densely populated urban area where
ground uplift and increasing ground temperature are observed,
connected with rising rates of CO2 emission. A major
pathway of CO2 release at Campi Flegrei is diffuse soil
degassing, and therefore quantifying diffuse CO2 emission
rates is of vital interest. Conventional in situ probing of soil
gas emissions with accumulation chambers is accurate over
a small footprint but requires significant time and effort to
cover large areas. An alternative approach is differential absorption
lidar, which allows for a fast and spatially integrated
measurement. Here, a portable hard-target differential absorption
lidar has been used to acquire horizontal 1-D profiles
of column-integrated CO2 concentration at the Solfatara
crater. To capture heterogenic features in the CO2 distribution,
a 2-D tomographic map of the CO2 distribution
has been inverted from the 1-D profiles. The scan was performed
one-sided, which is unfavorable for the inverse problem.
Nonetheless, the result is in agreement with independent
measurements and furthermore confirms an area of anomalous
CO2 degassing along the eastern edge as well as the
center of the Solfatara crater. The method may have important
implications for measurements of degassing features that
can only be accessed from limited angles, such as airborne
sensing of volcanic plumes. CO2 fluxes retrieved from the
2-D map are comparable, but modestly higher than emission
rates from previous studies, perhaps reflecting an increase in
CO2 flux or a more integrated measurement or both.
Campi Flegrei (Italy), a densely populated urban area where
ground uplift and increasing ground temperature are observed,
connected with rising rates of CO2 emission. A major
pathway of CO2 release at Campi Flegrei is diffuse soil
degassing, and therefore quantifying diffuse CO2 emission
rates is of vital interest. Conventional in situ probing of soil
gas emissions with accumulation chambers is accurate over
a small footprint but requires significant time and effort to
cover large areas. An alternative approach is differential absorption
lidar, which allows for a fast and spatially integrated
measurement. Here, a portable hard-target differential absorption
lidar has been used to acquire horizontal 1-D profiles
of column-integrated CO2 concentration at the Solfatara
crater. To capture heterogenic features in the CO2 distribution,
a 2-D tomographic map of the CO2 distribution
has been inverted from the 1-D profiles. The scan was performed
one-sided, which is unfavorable for the inverse problem.
Nonetheless, the result is in agreement with independent
measurements and furthermore confirms an area of anomalous
CO2 degassing along the eastern edge as well as the
center of the Solfatara crater. The method may have important
implications for measurements of degassing features that
can only be accessed from limited angles, such as airborne
sensing of volcanic plumes. CO2 fluxes retrieved from the
2-D map are comparable, but modestly higher than emission
rates from previous studies, perhaps reflecting an increase in
CO2 flux or a more integrated measurement or both.
Type
article
File(s)
Loading...
Name
2016_Solfatara_AMT.pdf
Size
5.92 MB
Format
Adobe PDF
Checksum (MD5)
4b243350b8ede1bf0c64ed966a6396a4