When magma rises towards the surface in volcanic systems, volatile species exsolve from the melt and are degassed to the atmosphere. The composition and emission rate of the emitted gases are diagnostic of the conditions from which the volatiles originate. In particular, the primitive melt composition, the pressure and depth at which degassing occurs, and the volume of ascending magma all determine the characteristics of the gas emissions at the surface. Interpreted in a petrological framework, gas measurements thus provide information on these fundamental parameters of volcanic systems.
Volcanic gases have traditionally been sampled in the field and later analyzed with standard laboratory methods, but remote sensing measurements have also played a central role in characterizing emissions. Instrumentation developed primarily for investigating atmospheric chemistry and air pollution were found to be valuable tools applicable to volcanoes. Starting in the 1970’s, instruments such as the Correlation Spectrometer (COSPEC) allowed the first direct measurements of the rate at which gases streamed out of a volcanic vent. At around the same time, the Total Ozone Mapping Spectrometer (TOMS) provided the first space-based SO2 detection and tracking capabilities on a global scale.
Since that time, remote sensing technology continues to play an important role in volcano observation. Ground-based instruments such as Differential Optical Absorption Spectrometers (DOAS) and Fourier Transform Infrared Spectrometers (FTIR) allow quantitative detection of a variety of volcanic gas species without the need for in situ sampling. Even more recently, SO2 cameras, Fabry Perot interferometers, and Imaging DOAS systems provide 2D imagery of volcanic plumes at high time resolution. And ever-improving satellite sensor technology has led to space-based imaging at unprecedented sensitivity, with instruments such as TROPOMI, IASI, and OCO-2 probing volcanic gases at wavelengths ranging from the ultraviolet to the infrared at much higher spatial resolution than ever possible before.
In this Research Topic, we take a snapshot of the state-of-the-art in volcanic gas remote sensing. We examine the advantages and drawbacks of the various technologies and retrieval methods and look for synergies between them. We welcome contributions that focus on the techniques themselves, but also explicitly encourage studies that apply remote sensing methods to gain insights into otherwise inaccessible volcanic processes. Clearly, gas remote sensing already plays an important role in volcano monitoring and research. But it is our belief that, through a combination of technological advances, innovative applications, and multi-disciplinary interpretations, remote sensing of volcanic gases can help answer additional fundamental questions about volcanism and the flux of volatiles to the atmosphere, as well as provide diagnostic information for use by observatories in eruption forecasts.
When magma rises towards the surface in volcanic systems, volatile species exsolve from the melt and are degassed to the atmosphere. The composition and emission rate of the emitted gases are diagnostic of the conditions from which the volatiles originate. In particular, the primitive melt composition, the pressure and depth at which degassing occurs, and the volume of ascending magma all determine the characteristics of the gas emissions at the surface. Interpreted in a petrological framework, gas measurements thus provide information on these fundamental parameters of volcanic systems.
Volcanic gases have traditionally been sampled in the field and later analyzed with standard laboratory methods, but remote sensing measurements have also played a central role in characterizing emissions. Instrumentation developed primarily for investigating atmospheric chemistry and air pollution were found to be valuable tools applicable to volcanoes. Starting in the 1970’s, instruments such as the Correlation Spectrometer (COSPEC) allowed the first direct measurements of the rate at which gases streamed out of a volcanic vent. At around the same time, the Total Ozone Mapping Spectrometer (TOMS) provided the first space-based SO2 detection and tracking capabilities on a global scale.
Since that time, remote sensing technology continues to play an important role in volcano observation. Ground-based instruments such as Differential Optical Absorption Spectrometers (DOAS) and Fourier Transform Infrared Spectrometers (FTIR) allow quantitative detection of a variety of volcanic gas species without the need for in situ sampling. Even more recently, SO2 cameras, Fabry Perot interferometers, and Imaging DOAS systems provide 2D imagery of volcanic plumes at high time resolution. And ever-improving satellite sensor technology has led to space-based imaging at unprecedented sensitivity, with instruments such as TROPOMI, IASI, and OCO-2 probing volcanic gases at wavelengths ranging from the ultraviolet to the infrared at much higher spatial resolution than ever possible before.
In this Research Topic, we take a snapshot of the state-of-the-art in volcanic gas remote sensing. We examine the advantages and drawbacks of the various technologies and retrieval methods and look for synergies between them. We welcome contributions that focus on the techniques themselves, but also explicitly encourage studies that apply remote sensing methods to gain insights into otherwise inaccessible volcanic processes. Clearly, gas remote sensing already plays an important role in volcano monitoring and research. But it is our belief that, through a combination of technological advances, innovative applications, and multi-disciplinary interpretations, remote sensing of volcanic gases can help answer additional fundamental questions about volcanism and the flux of volatiles to the atmosphere, as well as provide diagnostic information for use by observatories in eruption forecasts.
