Marine silicate weathering in the anoxic sediment of the Ulleung Basin: Evidence and consequences

Kim, Ji Hoon; Torres, Marta E; Haley, Brian A.; Ryu, Jong-Sik; Park, Myong-Ho; Hong, Wei‐Li; Choi, Jiyoung

doi:10.1002/2016gc006356

Cited by 36 publications

(26 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These depletions also coincide with decreasing total alkalinity and a sudden drop of pH from 8.1 to 7.9. In agreement with results from previous investigations (Michalopoulos and Aller, 1995;Wallmann et al, 2008;Kim et al, 2016), these findings are consistent with secondary clay authigenesis (reverse weathering), a process that releases CO 2 , which leads to removal of major cations/anions in the surrounding IW, thereby explaining the observed drop of pH and IW geochemical patterns, respectively.…”

Section: Principal Resultssupporting

confidence: 81%

Untitled

Rosenthal

Holbourn

Kulhanek³

et al. 2017

International Ocean Discovery Program Scientific Prospectus

View full text Add to dashboard Cite

Section: Principal Resultssupporting

confidence: 81%

Untitled

Rosenthal

Holbourn

Kulhanek³

et al. 2017

International Ocean Discovery Program Scientific Prospectus

View full text Add to dashboard Cite

“…This CO 2 would dissociate to HCO 3 − and H + , causing a pH decrease. This step, in turn, would favor weathering of silicate minerals in marine sediments (Marine Silicate Weathering-MSiW), resulting in alkalinity production and pH buffering (Aloisi et al, 2004;Wallmann et al, 2008;Solomon et al, 2014;Kim et al, 2016;Wehrmann et al, 2016, Eq. 4).…”

Section: Dic Sources At Smtzmentioning

confidence: 99%

Dissolved Inorganic Carbon Pump in Methane-Charged Shallow Marine Sediments: State of the Art and New Model Perspectives

et al. 2020

View full text Add to dashboard Cite

Methane transport from subsurface reservoirs to shallow marine sediment is characterized by unique biogeochemical interactions significant for ocean chemistry. Sulfate-Methane Transition Zone (SMTZ) is an important diagenetic front in the sediment column that quantitatively consumes the diffusive methane fluxes from deep methanogenic sources toward shallow marine sediments via sulfate-driven anaerobic oxidation of methane (AOM). Recent global compilation from diffusion-controlled marine settings suggests methane from below and sulfate from above fluxing into the SMTZ at an estimated rate of 3.8 and 5.3 Tmol year −1 , respectively, and wider estimate for methane flux ranges from 1 to 19 Tmol year −1. AOM converts the methane carbon to dissolved inorganic carbon (DIC) at the SMTZ. Organoclastic sulfate reduction (OSR) and deep-DIC fluxes from methanogenic zones contribute additional DIC to the shallow sediments. Here, we provide a quantification of 8.7 Tmol year −1 DIC entering the methane-charged shallow sediments due to AOM, OSR, and the deep-DIC flux (range 6.4-10.2 Tmol year −1). Of this total DIC pool, an estimated 6.5 Tmol year −1 flows toward the water column (range: 3.2-9.2 Tmol year −1), and 1.7 Tmol year −1 enters the authigenic carbonate phases (range: 0.6-3.6 Tmol year −1). This summary highlights that carbonate authigenesis in settings dominated by diffusive methane fluxes is a significant component of marine carbon burial, comparable to ∼15% of carbonate accumulation on continental shelves and in the abyssal ocean, respectively. Further, the DIC outflux through the SMTZ is comparable to ∼20% of global riverine DIC flux to oceans. This DIC outflux will contribute alkalinity or CO 2 in different proportions to the water column, depending on the rates of authigenic carbonate precipitation and sulfide oxidation and will significantly impact ocean chemistry and potentially atmospheric CO 2. Settings with substantial carbonate precipitation and sulfide oxidation at present are contributing CO 2 and thus to ocean acidification. Our synthesis emphasizes the importance of SMTZ as not only a methane sink but also an important diagenetic front for global DIC cycling. We further underscore the need to incorporate a DIC pump in methane-charged shallow marine sediments to models for coastal and geologic carbon cycling.

show abstract

“…The physical erosion of rocks in terrestrial environments delivers detrital silicate materials (e.g., feldspar, olivine, pyroxene, volcanic ash, and clays) to the marine environment where they can make up a significant portion of marine sediments. Here, recent work provides compelling geochemical evidence for potentially substantial rates of silicate dissolution in marine sediments (e.g., Kim et al, ; Maher et al, ; Maher et al, ; Scholz et al, ; Solomon et al, ; Wallmann et al, ). This is perhaps unsurprising as seawater and porewaters are generally undersaturated with respect to primary silicate minerals, and thus, their dissolution plays a role in buffering pore fluid pH and chemistry.…”

Section: Global Carbon Cycle Budgetmentioning

confidence: 95%

“…Techniques used to fingerprint silicate mineral dissolution within sedimentary systems include the application of isotope tracers (e.g., 87 Sr/ 86 Sr, (Kim et al, ); 234 U/ 238 U (Maher et al, ; Maher et al, )) and the identification of “anomalous” alkalinity or cation (e.g., Mg 2+ and Ca 2+ ) fluxes (Scholz et al, ; Solomon et al, ; Wallmann et al, ) within porewaters. Unexpectedly high alkalinity fluxes can be used as tracers for silicate weathering by first establishing background in situ porewater alkalinity levels through the application of diagenetic reaction transport modeling (e.g., Scholz et al, ; Solomon et al, ; Wallmann et al, ).…”

Section: Global Carbon Cycle Budgetmentioning

confidence: 99%

Evolution of the Global Carbon Cycle and Climate Regulation on Earth

Isson

Planavsky

Coogan

et al. 2020

Global Biogeochemical Cycles

114

View full text Add to dashboard Cite

The existence of stabilizing feedbacks within Earth's climate system is generally thought to be necessary for the persistence of liquid water and life. Over the course of Earth's history, Earth's atmospheric composition appears to have adjusted to the gradual increase in solar luminosity, resulting in persistently habitable surface temperatures. With limited exceptions, the Earth system has been observed to recover rapidly from pulsed climatic perturbations. Carbon dioxide (CO2) regulation via negative feedbacks within the coupled global carbon‐silica cycles are classically viewed as the main processes giving rise to climate stability on Earth. Here we review the long‐term global carbon cycle budget, and how the processes modulating Earth's climate system have evolved over time. Specifically, we focus on the relative roles that shifts in carbon sources and sinks have played in driving long‐term changes in atmospheric pCO2. We make the case that marine processes are an important component of the canonical silicate weathering feedback, and have played a much more important role in pCO2 regulation than traditionally imagined. Notably, geochemical evidence indicate that the weathering of marine sediments and off‐axis basalt alteration act as major carbon sinks. However, this sink was potentially dampened during Earth's early history when oceans had higher levels of dissolved silicon (Si), iron (Fe), and magnesium (Mg), and instead likely fostered more extensive carbon recycling within the ocean‐atmosphere system via reverse weathering—that in turn acted to elevate ocean‐atmosphere CO2 levels.

show abstract

Marine silicate weathering in the anoxic sediment of the Ulleung Basin: Evidence and consequences

Cited by 36 publications

References 56 publications

Untitled

Untitled

Dissolved Inorganic Carbon Pump in Methane-Charged Shallow Marine Sediments: State of the Art and New Model Perspectives

Evolution of the Global Carbon Cycle and Climate Regulation on Earth

Contact Info

Product

Resources

About