Fuhr Michael m.drove@gmail.com 0000-0002-5169-6744 GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Wallmann Klaus kwallmann@geomar.de 0000-0002-1795-376X GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Dale Andy W adale@geomar.de GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Diercks Isabel idiercks@geomar.de 0009-0001-6814-8365 GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Kalapurakkal Habeeb Thanveer hkalapurakkal@geomar.de GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Schmidt Mark mschmidt@geomar.de 0000-0002-4298-9617 GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Sommer Stefan ssommer@geomar.de GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Böhnke-Brandt Stefanie sboehnke-brandt@geomar.de 0000-0002-3431-5452 GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Perner Mirjam mperner@geomar.de 0000-0003-1223-9310 GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Utrecht University UU https://www.uu.nl/ https://ror.org/04pp8hn57 2025 Total alkalinity during laboratory incubation experiments on enhanced benthic weathering in organic rich Baltic Sea sediments dataset https://doi.org/10.1594/PANGAEA.974079 2025-02-11T09:07:54 https://doi.org/10.1594/PANGAEA.974076 Enhanced mineral dissolution in the benthic environment is currently discussed as a potential technique for ocean alkalinity enhancement (OAE) to reduce atmospheric carbon dioxide (CO2) levels. This study explores how biogeochemical processes affect the dissolution of alkaline minerals in surface sediments during laboratory incubation experiments (January - May 2022). These involved introducing dunite and calcite to organic-rich sediments from the Baltic Sea under controlled conditions in an oxic environment. The sediment cores were incubated with Baltic Sea bottom water. Eight sediment cores were placed in a rack in an upright position. The bottom water was carefully removed via suction and replaced with a known volume (1.5 l – 2.0 l) of filtered (0.2 µm) Baltic Sea bottom water in order to remove pelagic auto- and heterotrophs and suspended particles. The volume of water added depended on the height of sediment in each core which varied slightly due to the recovery method. After this procedure, a gaseous headspace of ca. 10 cm was left in each core. Furthermore, the cores were equipped with adjustable stirring heads that contained ports for inserting optodes to continuously record pH and oxygen (O2) concentrations in the overlying water. In order to prevent anoxic conditions developing, ambient air was bubbled into the water column. The water column in each core was slowly and continuously flushed with a constant throughflow of 40 µl min-1 from a single reservoir of bottom water. The residence time of the water inside the cores was thus about 4 to 5 weeks. Bottom water samples were taken from the outflow of each core over a time period of several hours. Thus, samples represent the average outflow over the respective time period. Sampling intervals increased from daily during the first two weeks to every three to four days and weekly towards the end of the experiment. All samples were filtered through a 0.2 µm cellulose membrane filter and refrigerated in 25 ml ZinsserTM scintillation vials. Samples for total alkalinity (TA) were analyzed directly after sampling by titration of 1 ml of bottom/pore water with 0.02N HCl. Titration was ended when a stable purple color appeared. During titration, the sample was degassed by continuous bubbling with nitrogen to remove any generated CO2 and H2S. The acid was standardized using an IAPSO seawater standard. Fuhr Michael m.drove@gmail.com 0000-0002-5169-6744 Wallmann Klaus kwallmann@geomar.de 0000-0002-1795-376X Dale Andrew W Diercks Isabel idiercks@geomar.de 0009-0001-6814-8365 Kalapurakkal Habeeb Thanveer hkalapurakkal@geomar.de Schmidt Mark mschmidt@geomar.de 0000-0002-4298-9617 Sommer Stefan ssommer@geomar.de Böhnke Stefanie sboehnke-brandt@geomar.de 0000-0002-3431-5452 Perner Mirjam mperner@geomar.de 0000-0003-1223-9310 Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 2023 Disentangling artificial and natural benthic weathering in organic rich Baltic Sea sediments journal article Frontiers in Climate 5 https://doi.org/10.3389/fclim.2023.1245580 1245580 10.04167 10.04167 54.51667 54.51667 10.04167 54.51667 2022-01-13T11:30:00 2022-01-13T11:30:00 -27.0 -27.0 uncoded table RETAKE DAM CDRmare - RETAKE: CO2 removal by alkalinity enhancement: potential, benefits and risks https://retake.cdrmare.de/en/ GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 CDRmare Research Mission of the German Marine Research Alliance (DAM): Marine carbon sinks in decarbonisation pathways https://cdrmare.de/en/ GEOMAR - Helmholtz Centre for Ocean Research Kiel GEOMAR http://www.geomar.de https://ror.org/02h2x0161 Federal Ministry of Education and Research BMBF https://www.bmbf.de/ https://doi.org/10.13039/501100002347 03F0895A DAM CDRmare - RETAKE, GEOMAR https://foerderportal.bund.de/foekat/jsp/SucheAction.do?actionMode=view&fkz=03F0895A L22_core 54.51667 10.04167 -27.0 2022-01-13T11:30:00 Boknis Eck L22_daytrip Fuhr, Michael Geilert, Sonja 2022-01-13 2022-01-13 Littorina https://www2.bsh.de/aktdat/dod/fahrtplanung/Littorina.htm DLMG 7360942 MultiCorer, mini MCM Original sampling location of tested surface sediments; salinity: 21; water temperature: 4.2 °C 2184 CC-BY-4.0 Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ Additional information regarding the experimental set-up: * Laboratory: GEOMAR cool-lab (12.5 °C) * Treatments, added to sediment core of 10 cm diameter: Dunite (4.4781 g, manufacturer Sibelco), Calcite (7.8618 g, manufacturer unknown). * Baltic sea water sampled in Boknis Eck (Salinity: 21, Temperature: 4.2 °C) * Start of the experiments: 2022-01-14 (morning) * End of the experiments: 2022-05-07 (afternoon) Type of study Study type type Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Study type Sample type Samp type Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Samp type Sample ID Sample ID Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Sample ID Treatment Treat treatment Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Cal (1-3) = calcite addition, Dun (1-3) = dunite addition, C (1-2) = control experiment Treat Sampling date/time, experiment Date/time sampling exp Time T http://dbpedia.org/resource/Time Smartphone application, Apple, Clock [iPhone SE 2016] Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Date/time sampling exp Time in days Time d days Time T http://dbpedia.org/resource/Time Smartphone application, Apple, Clock [iPhone SE 2016] Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 Time d [days] Alkalinity, total AT mmol(eq)/l total https://www.oxforddictionaries.com/definition/american_english/total Molar Concentration Titration device, Metrohm, 775 Dosimat Geilert Sonja s.geilert@uu.nl 0000-0002-8971-5867 AT [mmol(eq)/l] CurationLevelC Enhanced curation https://wiki.pangaea.de/wiki/Curation_levels citable calcite dissolution dunite dissolution enhanced weathering incubation experiment Laboratory experiment geomar author108219 author29806 author29925 author41130 author551 author58703 author69819 author73523 author73528 author79234 author81765 author98493 award2769 basis27 campaign51250 curlevel30 event3203637 funder20473 geocode1599 geocode1600 geocode1601 geocode8128 inst20147 inst2519 journal17053 license21 method11341 method17309 method17332 param16065 param185520 param516121 param7059 param762 param87725 param96278 pi58703 project4757 project4784 ref131002 term242 term26955 term38253 term38841 term41013 term43975 term44030 term49506 term60791 term72655 term75168 term75177 topotype11