Heat Flow Distribution in the Chukchi Borderland and Surrounding Regions, Arctic Ocean

• Published in: Geochemistry, geophysics, geosystems : G3 geophysics, geosystems : G3, 2021-12, Vol.22 (12), p.n/a
• Main Authors: Zhang, T., Shen, Z. Y., Zhang, F., Ding, M.
• Format: Article
• Language: English
• Subjects: Arctic Ocean; Cenozoic; Chukchi Borderland; Continental margins; Corers; Cretaceous; Crustal thickness; Environmental changes; extension; Flow measurement; Fluctuations; Gas hydrates; Gravity; Heat conduction; Heat content; Heat flow; Heat flux; Heat flux measurements; Heat transfer; Heterogeneity; Hydrates; Jurassic; Lithosphere; Ocean floor; Oceanic crust; Oceans; Regions; Rifting; Sea ice; Seafloor spreading; Seismic profiles; Temperature; Water temperature
• ISSN: 1525-2027; 1525-2027
• DOI: 10.1029/2021GC010033

Fifty new heat flow measurements from the Chukchi Borderland (CBL) and adjacent regions of the central Arctic Ocean are reported, where heat flow measurements have been very limited. The average heat flow of the CBL (65 mW/m2) is significantly higher than that of the entire Amerasia Basin (53 mW/m2). In the CBL, the heat flow of the Chukchi Plateau (CP), Northwind Basin (NWB), and Northwind Ridge (NWR) are 64 mW/m2, 69 mW/m2, and 60 mW/m2, respectively. With the aid of nearby seismic profiles, the elevated regional heat flow in the CP and NWR was attributed to the enhanced radiogenic heating of the thick crust (25–29 km), while the most prominent heat flow in the relatively thin crust of the NWB is likely due to the residual heat of a major tectonic extension event. Further numerical heat conduction modeling suggests that the initial rifting of the Amerasia Basin during the Jurassic–Early Cretaceous could not induce such high heat flow in the NWB. Together with recent interpretations of seismic profiles, the elevated heat flow in the NWB could be explained by the residual heat of the Late Cretaceous–early Cenozoic extension. This extension event was contemporaneous with the seafloor spreading in the Makarov Basin and had also been associated with the onset of seafloor spreading in the Eurasia Basin. Plain Language Summary Heat flux through the seafloor elucidates the thermal evolution of the oceanic lithosphere, and environmental change factors, such as hydrothermal circulations, bottom‐water temperature perturbations, and gas hydrate stability. Seafloor heat flux is often determined using temperatures measured with a series of sensors mounted on the outside of gravity‐driven corers and thermal conductivities measured on the recovered sediment cores. Partly due to sea ice, heat flux measurement in the Arctic Ocean is quite difficult. Here, we present 50 new heat flow sites in Chukchi Borderland and adjacent regions in the central Arctic Ocean. We show that the heat flux in Chukchi Borderland is significantly higher than the average in the Amerasia Basin. Although the heterogeneity in radiogenic heat content and thickness of the crust could explain part of the high heat flux, the highest regional heat flux in Chukchi Borderland is best explained by a warm lithosphere that experienced tectonic extension during Late Cretaceous‐early Cenozoic. This extension event may share the same driving force of the subsequent opening of the Eurasia Basin. Key Points 50 ne