Hydrothermal Plumes Research Articles

Hydrothermal Plumes Act as a Regional Boundary Sink of 230Th in the Equatorial Pacific

AbstractAn important role in the cycling of marine trace elements is scavenging, their adsorption and removal from the water column by sinking particles. Boundary scavenging occurs when areas of strong particle flux drive preferential removal of the trace metals at locations of enhanced scavenging. Due to its uniform production and quick burial via scavenging, 230Th is used to assess sedimentary mass fluxes; however, these calculations are potentially biased near regions where net lateral transport of dissolved 230Th violates the assumption that the flux of particulate 230Th to the seabed equals its rate of production in the water column. Here, we present a water column transect of dissolved 230Th along 152° W between Alaska and Tahiti (GEOTRACES GP15), where we examine 230Th profiles across multiple biogeochemical provinces and, novelly, the lateral transport of 230Th to distal East Pacific Rise hydrothermal plumes. We observed a strong relationship between the slope of dissolved 230Th concentration‐depth profiles and suspended particle matter inventory in the upper‐mid water column, reinforcing the view that biogenic particle mass flux sets the background 230Th distribution in open ocean settings. We find that, instead of the region of enhanced particle flux around the equator, hydrothermal plumes act as a regional boundary sink of 230Th. At 152° W, we found that the flux‐to‐production ratio, and thereby error in 230Th‐normalized sediment flux, is between 0.80 and 1.50 for hydrothermal water, but the error is likely larger approaching the East Pacific Rise.

Hydrothermal Methane Venting and Its Microbial Oxidation Along the Eastern Southwest Indian Ridge, 63.5°–68°E

AbstractMethane concentration and its stable carbon isotope ratio studies were carried out in deep waters of ultraslow‐spreading eastern Southwest Indian Ridge (eSWIR), 63.5°–68°E, to identify hydrothermal plumes and associated biogeochemical processes. High methane concentrations (1.0–37.8 nmol/kg) confirm the presence of 11 hydrothermal plumes along the ∼500 km long section of eSWIR. Among these 11 plumes, eight are reporting for the first time. Detailed investigations near 67.67°E; 26.61°S show the presence of three plumes at various depths and their dispersion >100 km along the ridge in east‐west directions. Stable carbon isotope ratios of these plumes show lighter and heavier isotope enrichment (−40‰ to −3‰). Lighter isotope enrichment may indicate that methane could be derived from a combination of abiotic and thermogenic sources and, heavier isotope enrichment is mainly because of microbial methane oxidation. We report strong evidence for the presence of an active hydrothermal field at 67.67°E; 26.61°S in the eSWIR for the first time.

2024 IEEE Scientific Visualization Contest Winner: PlumeViz: Interactive Exploration for Multi-Facet Features of Hydrothermal Plumes in Sonar Images.

Plume visualization is essential for unveiling the dynamics of hydrothermal systems. This paper introduces an interactive exploration tool, PlumeViz, designed to facilitate the extraction and visualization of multifaceted plume characteristics from data collected by a sonar device. The tool addresses the challenges posed by undersampled volume data and intricate plume structures by providing an interactive platform for plume identification, visual representation, and analysis. Key functionalities of PlumeViz encompass comprehensive plume evolution, plume feature extraction, and in-depth exploration of specific regions of interest. We demonstrate the efficacy of PlumeViz in visualizing hydrothermal plumes through a case study and a range of illustrative results.

Dominance of Sulfur-Oxidizing Bacteria, Thiomicrorhabdus, in the Waters Affected by a Shallow-Sea Hydrothermal Plume.

The shallow-sea hydrothermal vent at Guishan Islet, located off the coast of Taiwan, serves as a remarkable natural site for studying microbial ecology in extreme environments. In April 2019, we investigated the composition of prokaryotic picoplankton communities, their gene expression profiles, and the dissolved inorganic carbon uptake efficiency. Our results revealed that the chemolithotrophs Thiomicrorhabdus spp. contributed to the majority of primary production in the waters affected by the hydrothermal vent plume. The metatranscriptomic analysis aligned with the primary productivity measurements, indicating the significant gene upregulations associated with carboxysome-mediated carbon fixation in Thiomicrorhabdus. Synechococcus and Prochlorococcus served as the prokaryotic photoautotrophs for primary productivity in the waters with lower influence from hydrothermal vent emissions. Thiomicrorhabdus and picocyanobacteria jointly provided organic carbon for sustaining the shallow-sea hydrothermal vent ecosystem. In addition to the carbon fixation, the upregulation of genes involved in the SOX (sulfur-oxidizing) pathway, and the dissimilatory sulfate reduction indicated that energy generation and detoxification co-occurred in Thiomicrorhabdus. This study improved our understanding of the impacts of shallow-sea hydrothermal vents on the operation of marine ecosystems and biogeochemical cycles.

Distribution and behaviour of reduced sulfur substances in the oligotrophic and hydrothermal waters of the Western Tropical South Pacific

Reduced sulfur species (RSS) are involved in essential biological and chemical processes, including metal complexation, yet little is known about their occurrence and behaviour in marine systems. Here, we present a quantitative and qualitative data set of species-specific RSS in open ocean samples collected during the GEOTRACES Tonga GPpr14 cruise. The cruise traversed differing biogeochemical provinces, from the mesotrophic Melanesian waters and the North Fiji Basin, through the hydrothermally active Lau Basin, eastward to the oligotrophic South Pacific Gyre. Using cathodic stripping voltammetry in acidified samples (pH 2), we measured the concentration of two RSS, with peak potentials of -0.18 and -0.09 V in equivalents of thioacetamide (TA) and glutathione (GSH) respectively. GSH-like compounds were only present in the upper 200 m at concentrations up to 6.2 nM eq. GSH, consistent with other cathodic stripping voltammetry as well as chromatography-based studies. In contrast, RSS−0.18 V2 compounds were detected at all depths at concentrations ranging from 48 nM to 980 nM eq. TA. Both RSS−0.18 V2 and GSH-like compounds were present at higher levels in the hydrothermally-impacted region of the Lau Basin relative to other stations. The highest levels, along with high sulfide concentrations, were detected in a hydrothermal plume sample, indicating that hydrothermal vents are a direct or indirect source of these compounds. Elevated levels of RSS−0.18 V2 compounds were detected throughout almost the entire water column at a station located in the North Fiji Basin. We also employed the qualitative technique of cathodic pseudopolarography on unbuffered samples (pH ~ 8.5). Pseudopolarograms of marine RSS were compared to sulfide, GSH and TA standards. Pseudopolarography supports the presence of GSH in marine samples. However, while a compound that is electrochemically similar to TA is often detected in marine samples, TA itself is not thought to be naturally present. This is supported by our pseudopolarograms of RSS−0.52 V8.5 which often lacked the characteristic TA reduction wave but suggested the presence of other unidentified RSS compounds.

Tracking hydrothermal particles from the ridge axis to the sediment column along the Endeavour segment of the Juan de Fuca Ridge

Tracking hydrothermal particles from the ridge axis to the sediment column along the Endeavour segment of the Juan de Fuca Ridge

Impact of submarine volcanic versus hydrothermal activity onto the strontium and lithium isotopic signatures of the water column (TONGA)

During the TONGA cruise (2019), seawater samples were collected to assess the effect of volcanic eruption versus submarine hydrothermal system on the water column. For this purpose, two locations were investigated, the first one located directly under the influence of the New Late’iki island (eruption in October 2019), and the second one showing ongoing submarine hydrothermal activity. At both locations, the total strontium (TSr) and lithium (TLi) concentrations vary between 94.4 and 152.3 µmol/L and 13.2 and 203.5 µmol/L, respectively. When combined, TSr and TLi concentrations of all samples in the water column are higher than those of the oligotrophic water. Both volcanic eruption and submarine hydrothermal activity (e.g. volcanic ashes, particles, gas condensate) can deliver substantial amount of TSr and TLi to the water column. The distribution of TSr versus TLi evidences linear trends either with a negative or positive slope. The negative correlation is observed in the water column at both sites, directly under the influence of the eruption and in the vicinity of the volcano with hydrothermal activity. The positive TSr versus TLi correlation is observed at site under submarine hydrothermal influence and is in line with black smokers related hydrothermal plumes. The 87Sr/86Sr ratios vary between 0.709147 and 0.709210 and δ7Li values vary between +10.1 and +37.6 ‰. While 92% of the measured 87Sr/86Sr ratios are in line with the mean value of oligotrophic waters, once combined with the δ7Li values, only 20% of them remains within this field. The wide range of δ7Li values decreases from sea-surface down to ~140 mbsl, before increasing at greater depth, while defining different linear trend according to the dissolved inorganic carbon concentrations. The variability of δ7Li values reflect hydrothermal contribution, mineral–seawater interaction and potentially biology–environment interaction. In the particular geological setting of the study, where both hydrothermal and volcanic activities were at play, disentangling both contributions on water column implies a combined use of elemental and isotopic signatures of Sr and Li tracers.

Transfer of rare earth elements from clay-sized fraction to phosphate in East South Pacific Ocean: Implication for REY-rich sediment related to hydrothermal influence

Transfer of rare earth elements from clay-sized fraction to phosphate in East South Pacific Ocean: Implication for REY-rich sediment related to hydrothermal influence

Hydrothermal vents supporting persistent plumes and microbial chemoautotrophy at Gakkel Ridge (Arctic Ocean).

Hydrothermal vents emit hot fluids enriched in energy sources for microbial life. Here, we compare the ecological and biogeochemical effects of hydrothermal venting of two recently discovered volcanic seamounts, Polaris and Aurora of the Gakkel Ridge, in the ice-covered Central Arctic Ocean. At both sites, persistent hydrothermal plumes increased up to 800 m into the deep Arctic Ocean. In the two non-buoyant plumes, rates of microbial carbon fixation were strongly elevated compared to background values of 0.5-1 μmol m-3 day-1 in the Arctic deep water, which suggests increased chemoautotrophy on vent-derived energy sources. In the Polaris plume, free sulfide and up to 360 nM hydrogen enabled microorganisms to fix up to 46 μmol inorganic carbon (IC) m-3 day-1. This energy pulse resulted in a strong increase in the relative abundance of SUP05 by 25% and Candidatus Sulfurimonas pluma by 7% of all bacteria. At Aurora, microorganisms fixed up to 35 μmol IC m-3 day-1. Here, metal sulfides limited the bioavailability of reduced sulfur species, and the putative hydrogen oxidizer Ca. S. pluma constituted 35% and SUP05 10% of all bacteria. In accordance with this data, transcriptomic analysis showed a high enrichment of hydrogenase-coding transcripts in Aurora and an enrichment of transcripts coding for sulfur oxidation in Polaris. There was neither evidence for methane consumption nor a substantial increase in the abundance of putative methanotrophs or their transcripts in either plume. Together, our results demonstrate the dominance of hydrogen and sulfide as energy sources in Arctic hydrothermal vent plumes.

Iron Isotopes reveal volcanogenic input during Oceanic Anoxic Event 2 (OAE 2 ∼ 94 Ma)

Iron Isotopes reveal volcanogenic input during Oceanic Anoxic Event 2 (OAE 2 ∼ 94 Ma)

Particle Concentrations and Sizes for the Onset of Settling‐Driven Gravitational Instabilities: Experimental Validation and Application to Volcanic Ash Clouds

AbstractSettling‐driven gravitational instabilities (SDGIs) can form at the base of buoyant particle‐laden suspensions, modulating particle sedimentation in various settings such as meteorological and volcanic clouds, fluvial plumes, magma chambers, submarine hydrothermal plumes, or industrial emissions. These instabilities result in the formation of rapidly descending currents called ‘fingers’ within which fine particles settle faster collectively than individually. This study investigates SDGI triggering conditions underneath volcanic ash clouds through analogue experiments considering sedimentation from aqueous particle suspensions. We confirm that the conditions for which SDGIs develop are controlled by two dimensionless numbers: Bf (ratio of the characteristic finger velocity to the individual particle settling velocity); and Bi (ratio of timescale for individual particle settling to that for collective settling controlled by inertial drag). SDGIs are triggered for values of Bf and Bi > 1 for which particles are fully coupled with the flow within fingers. Using these parameters, we produce a regime diagram for the 2010 eruption of Eyjafjallajökull (Iceland) that describes particle settling as a function of particle concentration and size. More studies are needed to produce a general regime diagram accounting for the evolution of SDGIs properties with eruption and atmospheric parameters. Nonetheless, our study confirms that fingers affect sedimentation from volcanic clouds with high ash volume fractions above 10−6 vol.%. Our validation of criteria predicting the onset of fingers due to SDGIs constitutes a step forward toward the incorporation of these collective settling processes in volcanic ash transport and dispersion models.

Symmetry breaking of rotating convection due to non-Oberbeck–Boussinesq effects

The non-Oberbeck–Boussinesq (NOB) effects arising from variations in thermal expansivity are theoretically and numerically studied in the context of rotating Rayleigh–Bénard convection in forms of two-dimensional rolls. The thermal expansivity increases with pressure (depth), and its variation is measured by a dimensionless factor ε. Utilizing an asymptotic expansion with weak nonlinearity, we derive an amplitude equation, revealing that NOB effects amplify the magnitude of convection. An ε2-order NOB correction leads to a symmetry breaking about the horizontal mid-plane, manifested in the strengthening of convection near the bottom and its weakening near the top, forming bottom-heavy profiles. At ε3-order, the conjunction of NOB effects and nonlinear advection leads to a horizontal symmetry breaking. The values of Taylor number and Prandtl number determine whether upward or downward plumes are stronger. Numerical calculations validate the theoretical analyses in weakly nonlinear regime. This work advances our understanding of hydrothermal plumes in some winter lakes on Earth and in the subglacial oceans on icy moons as well as tracer transport from the seafloor to the ice shell.

Dissolved Cu isotope compositions in hydrothermal plumes over back-arc volcanoes in the Northeast Lau Basin, Southwest Pacific Ocean

Dissolved Cu isotope compositions in hydrothermal plumes over back-arc volcanoes in the Northeast Lau Basin, Southwest Pacific Ocean

A hydrothermal plume on the Southwest Indian Ridge revealed by a multi-proxy approach: Impact on iron and manganese distributions (GEOTRACES GS02)

A hydrothermal plume on the Southwest Indian Ridge revealed by a multi-proxy approach: Impact on iron and manganese distributions (GEOTRACES GS02)

Suspended particulate matter influence on dissolved Nd concentration and isotopic composition along GEOTRACES section GP16

Suspended particulate matter influence on dissolved Nd concentration and isotopic composition along GEOTRACES section GP16

High-quality draft genome of Gammaproteobacterial SUP05 cluster from non-buoyant hydrothermal plumes of ultraslow spreading Gakkel Ridge (Central Arctic Ocean).

Hydrothermal plumes are an important yet understudied component of deep-sea microbial ecosystems. We report metagenome-assembled genomes (MAGs) of three Bacteria belonging to the Gammaproteobacterial SUP05 cluster (family Thioglobaceae), assembled from the metagenomes of two non-buoyant hydrothermal plumes in the ultraslow spreading Gakkel Ridge.

Coupled carbon‑iron‑phosphorus cycling in the Rainbow hydrothermal vent field

Coupled carbon‑iron‑phosphorus cycling in the Rainbow hydrothermal vent field

Hydrothermal Plume Fallout, Mass Wasting, and Volcanic Eruptions Contribute to Sediments at Loki's Castle Vent Field, Mohns Ridge

AbstractSediments surrounding hydrothermal vents are important transition spaces between hydrothermal and pelagic environments. These sediments accumulate through diverse processes that include water column plume fallout, volcanic ash deposition, and mass wasting of hydrothermal chimneys and mounds superimposed upon background sedimentation which may originate from pelagic, terrestrial, and volcanic sources. In addition to being a sink for elements discharged from hydrothermal vents, elements may also be scavenged from seawater onto oxidized hydrothermal material. Preservation of these hydrothermal sediments may occur depending on the extent of oxidative and/or reductive dissolution processes after burial. Sediments remaining adjacent to active venting may also be hydrothermally altered after emplacement. To better understand these processes, here we evaluate sediment push cores collected from the Loki's Castle vent field at the intersection of the slow‐ultraslow spreading Mohns and Knipovich mid‐ocean ridges. All samples were collected within ∼225 m of current high‐temperature (299–316°C) “black smoker” fluid discharge. These sediment cores are highly heterogeneous and lack stratigraphic correlation, even for samples taken within meters of each other. Most sediment cores are dominated by either pelagic sediments or mass wasted hydrothermal material, with hydrothermal plume fallout contributing a low proportion of material, and only a single volcanic ash layer occurring in one of the 13 cores. Dominant hydrothermal minerals found include talc, goethite, pyrite, pyrrhotite, and sphalerite. We find that even after several thousand years, most mass wasted hydrothermal material remains minimally altered, with sedimentation rates indistinguishable from background rates within several hundred meters of the hydrothermal vent source.

Geochemistry of iron and trace metals in seep carbonates of the middle Okinawa Trough impacted by hydrothermal plumes

Geochemistry of iron and trace metals in seep carbonates of the middle Okinawa Trough impacted by hydrothermal plumes

Geochemical Characteristics of Seabed Sediments in the Xunmei Hydrothermal Field (26°S), Mid-Atlantic Ridge: Implications for Hydrothermal Activity

The compositions of metalliferous sediments associated with hydrothermal vents can provide key geochemical data for locating seafloor sulfides. In this study, we present the geochemistry of seabed sediments from the Xunmei hydrothermal field (HF) in the South Mid-Atlantic Ridge (SMAR). The results indicate that the sediments are mainly composed of pelagic material (biogenic calcium components), basaltic debris, iron-manganese oxides, and hydrothermal components. The sediments are significantly enriched in Cu, Zn, Fe, and Co deriving from hydrothermal fluids, as well as Mn, V, Mo, U, and P, which are primarily scavenged from seawater. The northeastern Xunmei has the highest concentrations of Cu and Zn, while the northeastern, northern, and southern regions are characterized by great inputs of Fe. Manganese and Mo are mainly enriched in the western and southern parts and show a strong positive correlation, indicating that Mo is mainly scavenged by Mn oxides. Uranium, P, and Fe exhibit strong positive correlations, suggesting that they coprecipitate with Fe from hydrothermal plumes. Vanadium and Co are introduced into sediments in different ways: V is scavenged and coprecipitated by hydrothermal plumes, and Co is derived from sulfide debris. Based on the contents of Cu and Zn and Cu/Fe (0.159), Zn/Fe (0.158), and Fe/Mn (1440) ratios, it can be inferred that a high-temperature hydrothermal vent existed in northeastern Xunmei. In combination with the distribution patterns of the above elements, the hydrothermal vents in the southern part ceased erupting after a short period of activity. In addition, the high Mn anomaly and the high U/Fe ratios at the boundaries of the investigated area indicate the presence of a relatively oxidized environment in southwestern Xunmei.