In Summer 2023, several news come from the international heat flow community.
Background: What is heat flow?
The terrestrial heat-flow density (simply called ‘heat flow’) is a measure of thermal energy flowing from the core towards the Earth’s surface. It varies locally and is given as the rate of heat transferred across an area per unit time. Heat flow provides indispensable insights into the evolution of our planet and is paramount for the analysis of the Earth’s temperature field across spatial scales and time domains.
Terrestrial heat-flow data is an important basis, for example for:
- estimating geothermal resources
- plate tectonic (geodynamic) modelling
- studies of the compositional structure of the lithosphere
- investigation of thermal effects (paleoclimate, recent climate warming)
New heat-flow standards
In the last two years, experts at the international level intensively discussed the standards necessary for collecting and storing heat flow data and its evaluation. The result is a new database structure for capturing this important parameter and its associated metadata, allowing a systematic assessment of the quality of collected heat flow data. This will significantly improve thermal analysis and the modelling of the Earth's temperature field.
Evaluation of heat flow data
Terrestrial heat flow is a derived quantity that is not measurable directly. In order to determine the terrestrial heat flow, temperatures in the subsurface and the effective rock thermal conductivities must be identified. A variety of methods can determine or estimate these two measurable quantities. Therefore, a more detailed examination of its calculation is necessary to interpret the quality and validity of a heat flow value. The new database structure queries the information required for this and now compiles the over 70,000 entries from more than 1,400 publications step by step in an international approach.
Heat Flow Summer School and Workshops at GFZ
Together with the International Heat Flow Commission and the IUGG (International Union of Geodesy and Geophysics), the GFZ held a one-week course in July on the basics of geothermal heat flow determination and its interpretation. Five experts and colleagues from institutions in Germany, Mexico, Italy, and Australia contributed to the course. The 24 participants came from 17 different countries.
The Summer School was supported by the IUGG, the World Heat Flow Database Project, the project Innerspace, and the International Lithosphere Program (TF VIII). The Summer School strengthen the research and cooperation with South and Central America, as well as Africa and was accompanied by subsequent workshops.
New leadership of the "International Heat Flow Commission" IHFC
Sixty years ago, the IHFC was founded as an international heat flow commission within the IUGG. The objectives of this commission are to support investigations and studies on the determination and interpretation of terrestrial heat flow, provide data and methods, and offer a platform for international exchange. In the course of the regular General Assembly at the IUGG in Berlin in July, a new Commission was elected. Raquel Negrete-Aranda (Cicese, Mexico) will lead the commission as the new chair. From GFZ, Sven Fuchs (Head of Working Group 4.8.7: Exploration of Thermal Geosystems), who has been managing the global heat flow database with his team for four years, was elected as the new Vice Chair. Florian Neumann and Ben Norden (also WG 4.8.7) were also admitted to the commission.
For additional information, please visit:
- New IHFC heat flow database structure and evaluation
- Actual IHFC Heat Flow Database (Release 2023)
- Information on the IHFC and the “Global Heat Flow Database Project”