Satellite‐derived surface temperature and in situ measurement at Solfatara of Pozzuoli (Naples, Italy)

Abstract

Ground thermal anomalies in volcanic‐hydrothermal systems, where the outflow of hot fluids gives rise to fumarolic fields, soil degassing, and hot soils, have, up to now, rarely been investigated by using satellite. Here we report a comparison between surface temperature derived by satellite data and a large data set of measured soil temperatures and CO2 fluxes for a volcanic‐hydrothermal system, the Solfatara of Pozzuoli (Campi Flegrei, Italy). Surface temperatures derived from ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) data are compared with soil temperatures and CO2 fluxes from four surveys performed in 2003, 2010, and in 2014. The good match between the spatial distributions of computed and measured temperatures suggests the adequacy of satellite data to describe the Solfatara thermal anomaly, while the correspondence between temperatures and CO2 fluxes, evidences the link between degassing and heating processes. The ASTER derived surface temperatures (14–37°C) are coherent with those measured in the soil (10–97°C at 10 cm depth), considering the effect of the thermal gradients which characterize the degassing area of Solfatara. This study shows that satellite data can be a very powerful tool with which to study surface thermal anomalies, and can provide a supplementary tool to monitor thermal evolution of restless volcanoes.

Surface Temperature Multiscale Monitoring by Thermal Infrared Satellite and Ground Images at Campi Flegrei Volcanic Area (Italy)

“…Etna [5][6][7][8][9] and in the USA, Hawaiian volcanoes) and the information obtained by this monitoring tool is useful for defining the local hazard level. Moreover, the use of Thermal InfraRed (TIR) satellite sensors is also a consolidated technique [10][11][12][13][14][15][16] for monitoring the volcanic activity at different spatial resolutions: low (e.g., Meteosat Second Generation, MSG, or the Geostationary Environmental Satellite, GOES), moderate (e.g., MODIS, AVHRR, Sentinel 3) and high (e.g., Advanced Spaceborne Thermal Emission and Reflection Radiometer, ASTER, and Landsat 8) [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The development of remote sensing techniques aimed at the estimation of surface temperatures of lava flows, lava lakes, and domes, as well as fumaroles of active volcanic areas, has allowed significant improvements in volcano monitoring activity [6,[31][32][33][34].…”

The Spatial and Spectral Resolution of ASTER Infrared Image Data: A Paradigm Shift in Volcanological Remote Sensing

“…Hellman & Ramsey, 2004;Viramonte et al, 2005;Vaughan et al, 2012a;Vaughan et al, 2012b;Silvestri et al, 2016;Braddock et al, 2017;Caudron et al, 2018;Mia et al, 2018a;Mia et al, 2018b. Wright et al, 2010;Favalli et al, 2012;Wadge et al, 2012;Head et al, 2013.…”

Detection of Geothermal Anomalies in Hydrothermal Systems Using ASTER Data: The Caldeiras da Ribeira Grande Case Study (Azores, Portugal)

“…Several studies have applied RS techniques to study high temperature (>100 °C) fumarolic fields (e.g., [ 16 , 17 , 18 ]); however, the identification of hydrothermal (<100 °C) fumaroles has been challenging [ 19 ]. Nevertheless, a few studies have already shown the use of satellite data to recognize anomalous thermal zones in hydrothermal systems, such as the studies carried out at the Nisyros (Greece) [ 20 ] and Solfatara (Italy) [ 21 ] volcanoes. Changes in the hydrothermal system of the Yellowstone Volcano (USA) were detected through thermal images in 2007; however, visible spectrum images allowed for the first signs of change in vegetation to be identified in 2001 [ 22 ] using high-resolution images.…”