# An Internet of Things (IoT) Application on Volcano Monitoring  
[PERSON]  
1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; [EMAIL_ADDRESS] (D.M. ); [EMAIL_ADDRESS] (P.T.-G.)1 Centre Geofisico de Canarias, Instituto Geografico Nacional, C/La Marina 20, 38001 S/C Tenerife, Spain; admoure@fomento. activity [13], variations in their emission rates, composition, and temperature may indicate a change in the volcanic system. Temperature monitoring of fumaroles and thermal anomalies can be made in situ and/or remotely. In situ measurements are carried out by direct contact sensors. The instrumentation employed depends on the range of the expected temperature values and the thermal area features. Usually, thermocouples and thermistors are the main direct contact sensors employed when measuring temperature at volcanic areas. These sensors have to be adequately protected against the corrosion of acid gases present at these sites. Although direct measurements are very precise, they are limited to cover a specific area or measuring individual points. Temperature monitoring can also be made remotely by measuring the thermal infrared radiation (TIR) emitted by a heated surface. Nevertheless, TIR can be partially or completely obscured by thick clouds, dust, water vapor, and/or ash plumes, so these types of measurements should preferably be made during favorable atmospheric conditions. A common instrument is the infrared camera, whether fixed or portable [14]. This device estimates the surface temperature by means of the infrared radiation measurement in each pixel over a specific wavelength range. Then, all measures are merged, forming an image using a false color palette in order to identify possible thermal anomalies. This is a useful tool in volcano monitoring, since it allows measuring temperature from a safe distance. However, due to the usually large areas that are recorded, the spatial resolution of images is low. The mentioned procedures imply either to make the measurement in situ or to use non-portable and costly systems. Considering this, the possibility for instrumental development that offers alternatives to the presented drawbacks remains open. Although in recent years different works framed in this context have been published [15; 16], there is still a very broad field in which to investigate. It is important to note that volcanic areas are usually remote and inaccessible with extreme environments, offering difficulties for communications, power supply, and maintenance. Thus, a compromise between the quality and consistency of retrieved data and the quantity of data delivered by the network, together with the cost and energetic requirement of the instrumentation must be reached. It would be desirable to develop portable, inexpensive (offering easy replacement), and low power consumption (since batteries or solar panels are often used as power supplies) instrumentation for monitoring the geochemical activity in real-time.