# An Internet of Things (IoT) Application on Volcano Monitoring
In the last decade, many works have reported deployments of monitoring systems using wireless sensor networks (hereinafter WSN), a non-traditional monitoring system, as a new alternative to be considered [17; 18]. WSNs are a group of specialized autonomous sensors and actuators with a wireless communications infrastructure, intended to monitor and control physical or environmental conditions at diverse locations, and to cooperatively pass their data to a main location through the network. As they can form networks independently, they can provide environmental information at low operational cost and without periodic maintenance. WSN solutions already cover a very broad range of application areas such as medical [19; 20; 21], environmental [22; 23], military [24; 25], precision agriculture [26; 27; 28], animal tracking [29; 30], smart spaces [31; 32], or surveillance [33; 34; 35], and research and technology advances continuously expand their application field. With their low power consumption and ease of deployment, WSN are a promising technology when considering volcano monitoring [36; 35]. For these reasons, Internet of Things (hereinafter IoT) has acquired great importance in this field. WSN is often a technology used within an IoT system [37]. The IoT enables any item or device with embedded electronics, sensors, actuators, and/or software to connect and exchange data over a network [38]. In the past years, there have been plenty of contributions of the IoT to different application areas such as environmental monitoring [39; 40; 41; 42], smart cities [43; 44], smart homes/smart building management [45; 46; 47], industries [48], healthcare [49], and surveillance [50; 51]. Regarding systems based on WSN for volcanic surveillance, most of the research done so far is only focused on the monitoring of seismic or deformation signs, while monitoring the temperature and gas intensity is rarely exposed, although they are important parameters related to volcanic activity [52; 53; 54; 55; 56]. This paper's contributions for researchers in the IoT applications to the volcanic monitoring field, can be summarized as:  
1. The first IoT implementation to measure soil temperature in volcanic areas, usually influenced by extreme weather conditions, high temperatures, and the presence of acid gases. 2. Detailed specifications, design considerations, and experimental results for a temperature wireless network. The network suits required and desirable features for volcanic monitoring such as real-time data acquisition, long-range communications, scalability and easy deployment, and also IoT requirements including low cost, low power, long-term service, and high reliability. 3. An extraordinarily energy efficient integration with a specifically design communication protocol. 4. A configuration-free, scalable, compact solution for a fast and effective deployment even in the case of volcanic unrest. The paper is further organized as follows. An introduction to IoT for volcano monitoring is done in Section 2. A detailed description of the network is documented in Section 3, followed by the measurement results and discussion in Section 4. Conclusions are shown in Section 5.