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The pandemic of Covid-19 detected for the first time in early March in Indonesia has been making people stay at home. It affects almost every sector, including higher education. Lecturer, staff, and students have been pushed to work and study from home. There are many approaches from the government, and the ultimate method is a full and partial lockdown. During March to May, with these techniques, it is not only can be temporary slow-down the case but also improved the quality of air. We have two fixed stations at Telkom University (-6.970, 107.629), with an altitude of around 650 and 670 m above sea level, respectively. Those locations were influenced by residential and industrial pollution under not so much open green spaces. Low-cost PM2.5 and CO2 sensors were deployed as well as monitoring meteorological parameters through cheap detectors. The system was equipped by an Internet of Things (IoT)-based modem for data transferring via the internet every 2-min. Results showed that PM2.5 mass concentrations were lower than usual cased in that location. Meanwhile, no significant evidence that the level concentration of CO2 is decreased. The decreasing mobility of people working and studying from home have been making less dirty air. It means that fewer aerosols can be identified in the air. The complex behavior between those polluted air and meteorological conditions have been tried to analyze, but no direct evidence that better air quality makes the outbreak is slowing down. [ABSTRACT FROM AUTHOR]

Tangkuban Parahu is located in the north of Bandung, the capital province of West Java. Several hydrothermal manifestations, such as hot and warm springs with a temperature of 29°C-80°C, indicate that the Tangkuban Parahu has potential as a geothermal prospect. In such a case, understanding the surface and subsurface geological structures in the prospect area is needed as the first step in geothermal exploration. This study identifies geological structures based on remote sensing and gravity datasets. Structural lineaments were extracted manually using GIS software to produce fault, and fracture density (FFD) maps from the DEMNAS dataset along with IFSAR and ALOS PALSAR images. Lineament extraction was performed at eight different sun azimuth angles (hillshade) to reduce non-meaningful lines that may appear. The FFD maps show that most of the surface manifestation correlates with the high FFD zones. Gravity method is one of the first steps in geothermal exploration to provide an overview of the distribution of rocks and subsurface geological structures. Gravity data were analyzed using the parasnis method to reflect the average of rock density. The derivative technique for gravity method is common to be applied in order to delineate subsurface geological structures [1]. In this research, we used First Horizontal Derivative (FHD) and Second Vertical Derivative (SVD) to determine the presence and the type of major fault. The results of this research indicate that most of the high FFD zones are located in the peak maximum of FHD, which has SVD=0. Nevertheless, there are 3 locations of the high FFD zone that have no peak maximum FFD. Integration of this analysis mostly shows that the existence of geological structures is related to surface hydrothermal manifestations. [ABSTRACT FROM AUTHOR]