The 2012 Pollino (Calabria, Italy) seismic sequence, culminating in the Mw 5.2 earthquake of 25 October 2012, is investigated, exploiting data collected during a long-term continuous radon monitoring experiment performed in the epicentral area from late 2011 to the end of 2014. We analyse data collected both using a phenomenological approach based on quantitative evidence and a purely numerical analysis including the following: (i) correlation and cross-correlation investigations; (ii) an original approach aimed at limiting the impact of meteorological parameters variations on the interpretation of measured radon levels; (iii) a change point analysis; (iv) the implementation of an original detection algorithm aimed at highlighting the connections between radon emission variations and major seismic events occurrence. Results from both approaches suggest that radon monitoring stations can be subject to massive site effects, especially regarding rainfall, making data interpretation harder. The availability of long-term continuous measurements is crucial to precisely assess those effects. Nevertheless, statistical analysis shows a viable approach for quantitatively relating radon emanation variations to seismic energy release. Although much work is still needed to make radon time series analysis a robust complement to traditional seismological tools, this work has identified a characteristic variation in radon exhalation during the preparation process of large earthquakes.

We share long term, continuous measurements of soil radon emanations in Italy acquired from 2009 to 2021 by the Italian Radon mOnitoring Network (IRON). The radon concentrations were measured at 62 stations and consist of 621 720 single measurements. Employed detectors are both in-house prototypes (LUCAS) and commercial devices (AER by Algade©), suitably calibrated at INGV radionuclide laboratory. In addiction to radon concentration, most stations acquire internal temperature, while a subset of them also record relative humidity. When available, all these data series are provided along with radon time series and consist of 1 320 710 local temperature and humidity data. The presented dataset allows monitoring variations in radon emissions on multiple time scales, using different analysis techniques. Potential investigations include the effect of environmental parameters/conditions on radon emissions, the study of the impact on such emissions of transient signals like those associated with seismic and volcanic preparation processes and fluid migration dynamics as well as analyses of risk for human health, related to prolonged exposure to radon gas accumulated in confined spaces.

We present an overview of the potential of active monitoring techniques to investigate the many factors affecting the concentration of radon in houses. We conducted two experiments measuring radon concentration in 25 apartments in Rome and suburban areas for two weeks and in three apartments in the historic center for several months. The reference levels of 300 and 100 Bq/m³ are overcome in 17% and 60% of the cases, respectively, and these percentages rise to 20% and 76% for average overnight radon (more relevant for residents’ exposure). Active detectors allowed us to identify seasonal radon fluctuations, dependent on indoor-to-outdoor temperature, and how radon travels from the ground to upper floors. High levels of radon are not limited to the lowest floors when the use of heating and ventilation produces massive convection of air. Lifestyle habits also reflect in the different values of gas concentration measured on different floors of the same building or in distinct rooms of the same apartment, which cannot be ascribed to the characteristics of the premises. However, the finding that high residential radon levels tend to concentrate in the historic center proves the influence of factors such as building age, construction materials, and geogenic radon.

Today, we have satellite images of Mars with a resolution of up to 24 cm per pixel. The planet has a thin atmosphere compared to Earth’s, but its surface is revealing itself to be active and complex. The use of images is an increasingly precise means of investigation for the study of transient phenomena that occur on the surface of the planet. We have developed a dating code that could be useful in the study of such phenomena. Thanks to this dating code, it is possible to immediately understand what season is in progress in the observed area starting from the terrestrial reference date of the photos taken by the orbiters. Some intermediate parameters of this calculation, such as the Martian year and the day of the year, can be equally useful for similar investigations. Satellite study of transient phenomena observable on the surface of Mars can range from geology (wind erosion and sedimentation) to meteorology (wind and phase transitions) to indigenous or non-indigenous biology.