Introducing the “analogs for Venus’ geologically recent surfaces” initiative: an opportunity for identifying and analyzing recently active volcano-tectonic areas of Venus trough a comparative study with terrestrial analogs

Several missions to Venus have been recently selected for launch [1–6], opening a new era for the exploration of the planet. One of the key questions that the future missions need to address is whether Venus is presently volcanically active [7–15]. Studying areas of active volcanism and tectonism on Venus is crucial to reveal clues about the geologic past of the planet, as well as provide information about the volatile content of its interior and the formation of its dense atmosphere. The “Analogsfor VENus’ GEologically Recent Surfaces” (AVENGERS) initiative aims to build a comprehensive database of terrestrial analog sites for the comparative study of recent and possibly on- going volcanic activity on Venus. Besides its scientific relevance, the AVENG- ERS initiative also acts as a bridge for international scientific collaboration, including the leadership and/or team members from the currently selected missions to Venus

Groundwater Level Variations in relation to Volcanic and Seismic Events. New Insights on Mt. Etna, Southern Italy

In this preliminary study, the response of Etnean groundwater levels (GWL) to seismic and volcanic events between 2003 and 2007 was investigated. This period was characterised by frequent volcanic and seismic activity. Groundwater timeseries were filtered for the effect of meteoric contribution by employing the Cumulative Rainfall Departure (CRD) approach; these were then examined for correlations with volcanic and/or seismic events. Noteworthy variations in GWLs were observed in the proximity of eruptive episodes. These seemed to be consistent with the variation of other parameters such as ground deformation and SO2 emissions previously investigated by other authors, and with the GWL fluctuations preceding the 2001–2002 seismic-volcanic crisis, detected by the Geochemical Monitoring System (GMS–2). Additionally, the variations observed before the phreatomagmatic explosion of January 12th, 2006, were the most evident among the whole examined period. With regard to this latter event, the GWL of wells to the S/SE sector of the volcano displayed a sudden and quasi-simultaneous lowering. These fluctuations commenced in November 2005 and were coincident with a moderate increase in the amplitude of volcanic tremor and mild inflation of the summit of the volcano, as recorded at permanent GPS stations. Less marked results have been obtained in relation to seismic events and it has not been viable to identify recurrent patterns of variation, mainly due to a low resolution of the available data.This work highlights how GWL variations might suggest, from days to months in advance, alterations to the geodynamic equilibrium of the Etnean region, providing evidence of the importance of groundwater monitoring and providing suggestions for future research. We envisage that this work will encourage the implementation of an efficient quantitative groundwater monitoring network which could reveal crucial information in the search for precursor signals

The first evaluation of the FY-3D/MERSI-2 sensor's thermal infrared capabilities for deriving land surface temperature in volcanic regions: a case study of Mount Etna

In November 2017, the China Meteorological Administration launched a new polar orbiting satellite in its Fengyun (FY) series: FY-3D. With its main purpose being the collection of meteorological data, FY-3D featured a comprehensive payload that is equally exploitable by various Earth Science disciplines. One of its sensors, the MEdium Resolution Spectral Imager-2 (MERSI-2), provides visible and infrared imagery at spatial resolutions of 250 - 1000 m. These characteristics make MERSI-2 suitable for volcanological remote sensing and make it comparable to the National Aeronautics and Space Administration's (NASA's) Moderate Resolution Imaging Spectroradiometer (MODIS) sensors which themselves, have been widely used in volcanological applications. This paper evaluates the first clear and near-coincident MODIS - MERSI-2 images of Mount Etna (Italy) during an active volcanic phase in 2019 and in turn, provides the first assessment of MERSI-2's utility in observing volcanic activity in the Thermal InfraRed (TIR). To ensure the comparability of both scenes, data from each were converted to Land Surface Temperature (LST) and comparisons were encouraging, with an r(2) of 0.92, a mean temperature discrepancy of 0.26 K and a root mean squared error of 0.75 K. Having ascertained comparability, we focussed on the absolute temperatures detected at the eruption site, with the highest being 317.3 K and 328.1 K for MODIS and MERSI-2, respectively. The 20 minute gap between the acquisitions is the most likely the cause of this temperature discrepancy, suggesting variations in lava effusion rates and activity were occurring at Mount Etna over such timescales. This study confirms the applicability of MERSI-2 for observing volcanic activity and emphasises the significance of TIR volcanic monitoring and the importance that additional spaceborne platforms might have in reducing temporal gaps between image acquisitions. Given its unique characteristics, future studies should investigate the applicability of MERSI-2 in more varied volcanic settings

Future orbiting and in-situ exploration of Venus: Mount Etna as terrestrial analogue

The exploration of Venus will soon experience a new golden era thanks to the recently selected NASA Deep Atmosphere of Venus Investigation of Noble gases, Chemistry and Imaging (DAVINCI) mission, NASA Venus Emissivity, Radio Science, InSAR, Topogra-phy & Spectroscopy (VERITAS) mission, and ESA EnVision mission. The DAVINCI mission will focus on the analysis of the the atmospheric vertical structure and composition of Earth’s twin planet and on the geologic structure of a tesserae terrain. The VERITAS mission will investigate the geologic fea-tures of its surface as well as geodynamic characteris-tics of the subsurface, providing high-resolution emis-sivity data, a global radar map at an approximate reso-lution of 30 meters/pixel, and estimation of the gravity anomaly of the shallow crust of the planet. The ESA EnVision mission will be complementary to the two NASA missions, providing high resolution 0.8-2.5 micron emissivity data, Synthetic Aperture Radar (SAR) data, and Subsurface Radar Sounder (SRS) data. Beyond those, the proposed Roscosmos-NASA Venera-D mission will also be equipped with an orbit-er that will investigate the atmospheric composition and circulation, as well as a lander that will analize the in-situ chemical composition and the surface-atmosphere interactions. While preparing for the new missions being selected and proposed on Venus, it is crucially important to select analogue areas on Earth that may be suitable for a direct comparison with orbiting and in-situ surface data to be retrieved in the near future from the future missions to Venus. We recently proposed active vol-canic areas of Venus, in particular Imdr Regio with its major volcanic structure Idunn Mons, as the likely most suitable target area for future orbiting and in-situ investigations on Venus. In this regard, we started the analysis and classification of the spectral features as well as chemical chararacteristics of the lava flow samples from potentially comparable terrestrial analogue locations, such as the Mount Etna composite volcano

Future orbiting and in-situ exploration of Venus: Mount Etna as terrestrial analogue.

The exploration of Venus will soon experience a new golden era thanks to the recently selected NASA Deep Atmosphere of Venus Investigation of Noble gases, Chemistry and Imaging (DAVINCI) mission, NASA Venus Emissivity, Radio Science, InSAR, Topogra-phy & Spectroscopy (VERITAS) mission, and ESA EnVision mission. The DAVINCI mission will focus on the analysis of the the atmospheric vertical structure and composition of Earth’s twin planet and on the geologic structure of a tesserae terrain. The VERITAS mission will investigate the geologic fea-tures of its surface as well as geodynamic characteris-tics of the subsurface, providing high-resolution emis-sivity data, a global radar map at an approximate reso-lution of 30 meters/pixel, and estimation of the gravity anomaly of the shallow crust of the planet. The ESA EnVision mission will be complementary to the two NASA missions, providing high resolution 0.8-2.5 micron emissivity data, Synthetic Aperture Radar (SAR) data, and Subsurface Radar Sounder (SRS) data. Beyond those, the proposed Roscosmos-NASA Venera-D mission will also be equipped with an orbit-er that will investigate the atmospheric composition and circulation, as well as a lander that will analize the in-situ chemical composition and the surface-atmosphere interactions. While preparing for the new missions being selected and proposed on Venus, it is crucially important to select analogue areas on Earth that may be suitable for a direct comparison with orbiting and in-situ surface data to be retrieved in the near future from the future missions to Venus. We recently proposed active vol-canic areas of Venus, in particular Imdr Regio with its major volcanic structure Idunn Mons, as the likely most suitable target area for future orbiting and in-situ investigations on Venus. In this regard, we started the analysis and classification of the spectral features as well as chemical chararacteristics of the lava flow samples from potentially comparable terrestrial analogue locations, such as the Mount Etna composite volcano

Idunn Mons as the landing site of the Venera-D mission:scientific relevance and possible operational tests on Mount Etna.

Along with the recently selected NASA DAVINCI [1] and VERITAS [2] missions, and with the ESA EnVision mission [3], the Roscosmos Venera-D mission [4, 5] opens the new decade of Venus exploration. Among these missions, the Venera-D is the only one to be equipped with a lander which could drill the surface of Venus and analyze its chemical composition. For this reason, it is crucial to select a future landing site based on its scientific relevance, as well as on safety constraints. We propose here Idunn Mons (Fig. 1a), a major large volcano of Imdr Regio, as the landing site for the Venera-D mission. We also indicate Mount Etna in Italy (Fig. 1b) as a suitable test site on Earth for drilling tests and in-situ elemental and mineralogical analyses [6, 7]