In our understanding of global geothermal heat flow, Greenland and the surrounding ocean floor has effectively been a blind spot. Now, scientist have dug up all available and somewhat unavailable heat flow data, creating ...
As it turns out, that the ground beneath Greenland is even colder than previously thought. This is one of the conclusions of a paper just published in Earth System Science Data by an international team of scientists lead by the Geological Survey of Denmark and Greenland (GEUS).
The researchers have compiled a new database and heat flow model consisting of all available geothermal heat flow data for the region. This involved a large amount of digging through "gray literature," or observations not previously included in data scarce Arctic heat flow models. The researchers used this observation database to make a new spatial map of heat flow in and around Greenland.
The new heat flow model, created with machine learning, shows that the mean heat flow on land is 44 mW/ m2 (milli Watt, meaning a thousandth of a Watt, per square meter). Which is substantially lower than what previous models have estimated. These models are based on significantly less data than the newly published one, in which 129 new measurements are included for a total of 419 measurements. For some of the previous heat flow models, the mean geothermal heat flow per unit was several times that of the newly published estimate.
Hotpots for geothermal energy
Spatial map depicting mean geothermal heat flow in and around Greenland derived from machine learning results. Heat anomalies appear off the coast of the capital area in the southwest, which might be interesting in relation to harvesting geothermal energy. In general, though, the heat flow from beneath Greenland is lower than previously estimated. Credit: Colgan and Wansing, 2022
Overview of site locations and types in the heat flow measurement database. Yellow dots denote sites where we reassess heat flow values presented in International Heat Flow Commission 2018 or other studies. Dashed line denotes our study boundary, 500 km from Greenland’s coasts. The Meighen and Barnes Ice Caps lie outside this boundary, but we still report these subglacial measurements here. Credit: . Credit: Colgan and Wansing, 2022
Example of a borehole supplying heat flow data in Greenland drilled just off the ice sheet close to Point 660 with the Isunnguata Sermia outlet glacier as backdrop. Credit: Lillemor Claesson Liljedahl