Surface heat flow measurements from the East Siberian continental slope and southern Lomonosov Ridge, Arctic Ocean

Abstract

Surface heat flow data in the Arctic Ocean are needed to assess hydrocarbon and methane hydrate distributions, and provide constraints into the tectonic origins and nature of underlying crust. However, across broad areas of the Arctic, few published measurements exist. This is true for the outer continental shelf and slope of the East Siberian Sea, and the adjoining deep water ridges and basins. Here we present 21 new surface heat flow measurements from this region of the Arctic Ocean. On the Southern Lomonosov Ridge, the average measured heat flow, uncorrected for effects of sedimentation and topography, is 57 6 4 mW/m 2 (n 5 4). On the outer continental shelf and slope of the East Siberian Sea (ESS), the average is 57 6 10 mW/m 2 (n 5 16). An anomalously high heat flow of 203 6 28 mW/m 2 was measured at a single station in the Herald Canyon. With the exception of this high heat flow, the new data from the ESS are consistent with predictions for thermally equilibrated lithosphere of continental origin that was last affected by thermotectonic processes in the Cretaceous to early Cenozoic. Variability within the data likely arises from differences in radiogenic heat production within the continental crust and overlying sediments. This can be further explored by comparing the data with geophysical constraints on sediment and crustal thicknesses.

Heat Flow in the Western Arctic Ocean (Amerasian Basin)

“…This implies that at least part of the explanation for the difference in heat flow (section ) among these physiographic provinces may be related to lower thermal gradients on AMR. The range of thermal conductivities measured on T‐3 cores from Mendeleev Ridge and Nautilus Basin is wider (Figure b) than that determined for sediments on the East Siberian continental slope and shelf (0.967 ± 0.026 to 1.099 ± 0.107 W m −1 K −1 , excluding the shallowest site at 120 m below sea level; O'Regan et al, ) using modern methods. The T‐3 heat flow measurements likely encountered a wider range of sediment types than the O'Regan et al () study.…”

“…The range of thermal conductivities measured on T‐3 cores from Mendeleev Ridge and Nautilus Basin is wider (Figure b) than that determined for sediments on the East Siberian continental slope and shelf (0.967 ± 0.026 to 1.099 ± 0.107 W m −1 K −1 , excluding the shallowest site at 120 m below sea level; O'Regan et al, ) using modern methods. The T‐3 heat flow measurements likely encountered a wider range of sediment types than the O'Regan et al () study. The Canada Basin thermal conductivity distribution is different from that in the other physiographic provinces, with measured values for T‐3 cores evenly distributed in the bins between 0.9 and 1.2 W m −1 K −1 (Figure b).…”

“…Compiled heat flow measurements for the Amerasian Basin and part of the Eurasian basin, color coded by measured heat flow, with the outline of the HAMH shown by the dashed white curve. T‐3 measurements are depicted as circles, CESAR ice island heat flow (Taylor et al, ) as diamonds, data collected roughly along 81°N (Jokat, ) as triangles, East Siberian margin data (O'Regan et al, ) as asterisks, recent Oden heat flow data and some additional previously unpublished data (Shephard et al, ) as crosses, and other historic heat flow measurements documented in the Global Heat Flow database (IHFC, ) as stars. Not shown is a recent survey of the Lomonosov Ridge by Xiao et al () nor Eurasian basin data from Urlaub et al ().…”

Thermal history and organic matter maturation modeling of the East Siberian Sea sedimentary basins

“…Замеры величины поверхностного теплового потока на территории Восточно-Сибирского моря есть для области его континентального склона [O'Regan et al, 2016], она составляет 50-52 мВт/м 2 наиболее близко к шельфовой части, а также в районе о. Большой Ляховский [Fujita et al, 1990] -50 мВт/м 2 . Температура на поверхности, по данным работы [Moran et al, 2006], в палеогеновое время достигала +24 °С, к середине эоцена снизились до +10 °С, к позднему миоцену в пределах Восточно-Сибирского моря уже присутствовал сезонный ледовый покров, в настоящее время среднегодовая поверхностная температура составляет в среднем -1 °С.…”

Heat Flow on the U.S. Beaufort Margin, Arctic Ocean: Implications for Ocean Warming, Methane Hydrate Stability, and Regional Tectonics

“…Reanalysis of these data confirms background heat flow averaging ~55 mW/m 2 in the Central and Western Canada Basin (Ruppel et al, 2019). Since the Lachenbruch and Mashall studies of the 1960s, only a handful of additional heat flow studies have been conducted in the Canada Basin, with most in shallow water along the Canadian continental margin or Russian waters (e.g., Jones et al, 1989; Riedel et al, 2015; O'Regan et al, 2016). Phrampus et al (2014) derived heat flow across the U.S. Beaufort Margin using bottom simulating reflections.…”