Discharge of Meteoric Water in the Eastern Norwegian Sea since the Last Glacial Period

Abstract

Submarine groundwater discharge could impact the transport of critical solutes to the ocean. However, its driver(s), significance over geological time scales, and geographical coverage are poorly understood. We characterize a submarine groundwater seep from the continental slope off northern Norway where substantial amount of meteoric water was detected. We reconstruct the seepage history from textural relationships and U‐Th geochronology of authigenic minerals. We demonstrate how glacial‐interglacial dynamics have promoted submarine groundwater circulation more than 100 km offshore and result in high fluxes of critical solutes to the ocean. Such cryosphere‐hydrosphere coupling is likely common in the circum‐Arctic implying that future decay of glaciers and permafrost in a warming Arctic is expected to attenuate such a coupled process and thus decreases the export of critical solutes.

Northeast Atlantic breakup volcanism and consequences for Paleogene climate change – MagellanPlus Workshop report

“…500 km from the shelf edge, where the maximum extent of glacier ice was during the Last Glacial Maximum (Patton et al, 2016). Similar signs of meteoric water were also observed along the continental shelf of the Norwegian margin (Egeberg and Aagaard, 1989) and more recently documented by Hong et al (2019) from the Lofoten-Vesterålen continental slope (∼ 800 m water depth and ca. 100 km from the Lofoten Archipelago).…”

Atmospheric Precipitation and Anomalous Upper Mantle in Relation to Intraplate Seismicity in Norway

“…Besides, the presence of zones of decreased salinity and increased temperature of seawater, including the fresh‐water Nordbreigrunnen spring 7 km off the Meløy area (Storrø, 2013) (Figure 1b), strongly supports our hypothesis that precipitation‐induced groundwater flow is present in the region. In addition, discharge of freshwater was recently detected at the continental slope off northern Norway (Hong et al, 2019), possibly indicating modern long‐distance groundwater flow. On the other hand, this discharge of meteoric water at the continental slope can be related to past groundwater circulation as a consequence of glacial‐interglacial dynamics (Hong et al, 2019).…”

“…In addition, discharge of freshwater was recently detected at the continental slope off northern Norway (Hong et al, 2019), possibly indicating modern long‐distance groundwater flow. On the other hand, this discharge of meteoric water at the continental slope can be related to past groundwater circulation as a consequence of glacial‐interglacial dynamics (Hong et al, 2019). Unfortunately, there is yet no direct data on underwater fresh‐water springs in the open sea off Western Norway.…”

Cold Seeps in a Warming Arctic: Insights for Benthic Ecology

“…No free gas (bubbling of gas from the seafloor) has been observed at this location; however, sediment porewater fluids are enriched in dissolved gases of reduced compounds. Isotope analyses of porewater fluids indicate that dissolved methane is of biogenic origin, although the actual sources are still being investigated (Hong et al, 2019). In addition to methane seepage at the canyons, there is a freshwater discharge from submarine groundwater reservoirs, which is suggested to considerably influence the local circulation and ocean chemistry in the area (Hong et al, 2019).…”

“…Dating of vesicomyid shells suggest that these chemosymbiotic bivalves disappeared from Arctic seeps approximately 15,000 years ago (Ambrose et al, 2015;Hansen et al, 2017Hansen et al, , 2020. Since carbonates with preserved remains of frenulate tubes from Arctic seep sites have been dated to a minimum of 20,000 years old (Hong et al, 2019), the chemosymbiotic megafaunal communities of Arctic seeps in the past likely consisted of large bivalves along with siboglinids.…”