ALBERT

Description: Heat-flow density is a basic parameter required for studying thermal processes of the Earth. Heat-flow data contribute to our understanding of large-scale geodynamic processes such as plate tectonics, the fundamental planetary energy balance, local and regional processes such as neotectonic activity, fluid flow or mineralization, the selection and location of geothermal energy projects, and the geological record of past land surface temperature changes. Since 1963, the International Heat Flow Commission (IHFC) has been fostering the compilation of the Global Heat Flow Database to provide reliable heat-flow data. However, the data stored prevously were often incomplete and did not follow modern database standards. In 2020, the IHFC initiated an international collaboration to review the Global Heat Flow Database (GHFD) and to benefit from new developments in information technology. Therefore, a reorganization of the database structure and a re-assessment of the stored data was started. In the last two years, the standards necessary for collecting, storing, and evaluation of heat flow data were intensively discussed. The result is a new database structure for capturing this important parameter and associated metadata and a systematic quality assessment scheme. The quality scheme, for the first time, combines three independent quality criteria in one combined score, comprising the quantified uncertainty, the methodological quality, and the status of overruling (site) effects. It allows a quick comparison of heat-flow data and reveals missing data or insufficient documentation at one glance. With the new quality scheme, users can select appropriate heat-flow values for their specific scientific purpose. The most recent intermediate update of the GHFDB – the data release 2023 – is the first release that partly considers the new structure. It contains data generated between 1939 and 2022 and comprises 73,033 heat-flow data from 1,414 publications. Because the process to screen and update incomplete, wrong or empty database entries requires to look-up primary publications, this process is ongoing and will last for a couple of years. Finally, the new GHFDB will significantly improve thermal analysis and the modelling of the Earth's temperature field.