Opin vísindi

Hydrothermal and Cold Spring Water and Primary Productivity Effects on Magnesium Isotopes: Lake Myvatn, Iceland

Hydrothermal and Cold Spring Water and Primary Productivity Effects on Magnesium Isotopes: Lake Myvatn, Iceland


Title: Hydrothermal and Cold Spring Water and Primary Productivity Effects on Magnesium Isotopes: Lake Myvatn, Iceland
Author: Pogge von Strandmann, Philip A. E.
Burton, Kevin W.
Opfergelt, Sophie
Eiríksdóttir, Eydís Salóme
Murphy, Melissa J.
Einarsson, Árni
Gíslason, Sigurður R.
Date: 2020-04-30
Language: English
Scope: 109
University/Institute: Háskóli Íslands
University of Iceland
School: Verkfræði- og náttúruvísindasvið (HÍ)
School of Engineering and Natural Sciences (UI)
Department: Jarðvísindastofnun (HÍ)
Institute of Earth Sciences (UI)
Líf- og umhverfisvísindastofnun (HÍ)
Institute of Life and Environmental Sciences (UI)
Náttúrurannsóknastöðin við Mývatn (HÍ)
Mývatn Research Station (UI)
Series: Frontiers in Earth Science;8
ISSN: 2296-6463
DOI: 10.3389/feart.2020.00109
Subject: Carbonate chemistry; Groundwater; Hydrothermal spring; Isotope geochemistry; Phytoplankton; Weathering; Jarðhitasvæði; Ferskvatn; Jarðeðlisfræði; Veðrun
URI: https://hdl.handle.net/20.500.11815/2370

Show full item record

Citation:

Pogge von Strandmann PAE, Burton KW, Opfergelt S, Eiríksdóttir ES, Murphy MJ, Einarsson A and Gislason SR (2020) Hydrothermal and Cold Spring Water and Primary Productivity Effects on Magnesium Isotopes: Lake Myvatn, Iceland. Frontiers in Earth Science 8:109. doi: 10.3389/feart.2020.00109

Abstract:

Lake Myvatn, Iceland, is one of the most biologically productive lakes in the northern hemisphere, despite seasonal ice cover. Hydrothermal and groundwater springs make up the dominant source to this lake, and we investigate their Mg isotope ratio to assess the effect of mid-ocean ridge hydrothermal springs, which are the primary modern sink of seawater magnesium. We also examine a time series in the only outflow from this lake, the Laxa River, to assess the effects of seasonal primary productivity on Mg isotopes. In the hydrothermal waters, there is a clear distinction between cold waters (largely unfractionated from primary basalt) and relatively hot waters, which exhibit over 1‰ fractionation, with consequences for the oceanic mass balance if the hydrothermal removal of Mg is not fully quantitative. The outflow Mg isotopes are similar to basalts (δ26Mg = −0.2 to −0.3) during winter but reach a peak of ∼0‰ in August. This fractionation corresponds to calcite precipitation during summer in Lake Myvatn, preferentially taking up light Mg isotopes and driving the residual waters isotopically heavy as observed, meaning that overall the lake is a CO2 sink.

Description:

Publisher's version (útgefin grein)

Rights:

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Files in this item

This item appears in the following Collection(s)