Gases and Emanations at the Geosphere-Atmosphere Interface and Their Relevance for Geothermal System Analysis

Abstract

The composition of soil gas and degassing rates at Earth’s surface provide insights into the characteristics of volcanic-geothermal systems and represent an image of processes at depth and on its way to the surface. The different techniques of soil gas measurements are useful both for fundamental and applied research, such as fault zone analysis, geothermal exploration, hazard assessment and monitoring. Based on area-wide field surveys in different geothermal settings we aim to develop a geothermal gas fingerprint with focus on overall soil gas composition and spatial variability. This requires the compilation of a substantial and representative database. We will to introduce our concept for a comprehensive, area-wide and systematic understanding of gases and emanations at the geosphere-atmosphere interface taking the entire geothermal system into consideration. Only a systematic approach will pave the way for a holistic system characterization, allowing the transferability of results to a spatial dimension for further correlation with data from other scientific disciplines (e.g., geophysics, structural geology, remote sensing). Therefore, key parameters, sampling techniques, data processing and interpretation, and the necessity of interdisciplinary approaches will be described.