Marta Torres

Marta Torres
Oregon State University | OSU · College of Earth, Ocean and Atmospheric Sciences

About

264
Publications
11,852
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2,452
Citations
Citations since 2017
21 Research Items
1461 Citations
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2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250

Publications

Publications (264)
Article
Full-text available
Archaea mediating anaerobic methane oxidation are key in preventing methane produced in marine sediments from reaching the hydrosphere; however, a complete understanding of how microbial communities in natural settings respond to changes in the flux of methane remains largely uncharacterized. We investigate microbial communities in gas hydrate-bear...
Article
Full-text available
Volume-dependent magnetic susceptibility (κ) is commonly used for paleoenvironmental reconstructions in both terrestrial and marine sedimentary environments where it reflects a mixed signal between primary deposition and secondary diagenesis. In the marine environment, κ is strongly influenced by the abundance of ferrimagnetic minerals regulated by...
Article
The response of Arctic Ocean biogeochemistry to subsurface flow driven by permafrost thaw is poorly understood. We present dissolved chloride and water isotopic data from the Chukchi Sea Shelf sediments that reveal the presence of a meteoric subsurface flow enriched in cations with a radiogenic Sr fingerprint. This subsurface fluid is also enriched...
Article
Anaerobic methanotrophic archaea consume methane in marine sediments, limiting its release to the water column, but their responses to changes in methane and sulfate supplies remain poorly constrained. To address how methane exposure may affect microbial communities and methane‐ and sulfur‐cycling gene abundances in Arctic marine sediments, we coll...
Article
We emphasize the importance of marine silicate weathering (MSiW) reactions in anoxic sediment as fundamental in generating alkalinity and cations needed for carbonate precipitation and preservation along continental margins. We use a model that couples thermodynamics with aqueous geochemistry to show that the CO 2 released during methanogenesis res...
Article
Full-text available
Submarine mud volcanoes (MVs) along continental margins emit mud breccia and globally significant amounts of hydrocarbon-rich fluids from the subsurface, and host distinct chemosynthetic communities of microbes and macrofauna. Venere MV lies at 1,600 m water depth in the Ionian Sea offshore Italy and is located in a forearc basin of the Calabrian a...
Article
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We report a rare observation of a mini-fracture in near-surface sediments (30 cm below the seafloor) visualized using a rotational scanning X-ray of a core recovered from the Lomvi pockmark, Vestnesa Ridge, west of Svalbard (1200 m water depth). Porewater geochemistry and lipid biomarker signatures revealed clear differences in the geochemical and...
Article
Full-text available
We report on a rare observation of a mini-fracture in near-surface sediments (30cm below the seafloor) visualized using rotational scanning X-ray of a core recovered from the Lomvi pockmark, Vestnesa Ridge west of Svalbard (1200m water depth). Porewater geochemistry and lipid biomarker signatures revealed clear differences in the geochemical and bi...
Article
Full-text available
Submarine mud volcanoes release sediments and gas-rich fluids at the seafloor via deeply-rooted plumbing systems that remain poorly understood. Here the functioning of Venere mud volcano, on the Calabrian accretionary prism in ~1,600 m water depth is investigated, based on multi-parameter hydroacoustic and visual seafloor data obtained using ship-b...
Data
Supplementary Figures, Supplementary Tables and Supplementary References
Article
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Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discha...
Article
Information about diagenetic processes and temperatures during burial of sediments entering the subduction zone is important for understanding changes in physical properties and seismic behavior during deformation. The geochemistry of authigenic carbonates from accretionary prisms can serve as proxies for conditions during carbonate cementation and...
Article
Full-text available
In this paper, we present a reduced model of methane hydrate formation in variable salinity conditions, with details on the equilibrium phase behavior adapted to a case study from Ulleung Basin. The model simplifies the comprehensive model considered by Liu and Flemings using common assumptions on hydrostatic pressure, geothermal gradient, and phas...
Article
Marine silicate weathering (MSiW) in anoxic sediments has been recently shown to be a significant sink for CO2 generated by methanogenesis. Independently, the roles of clay dehydration (illitization) in producing water and driving upward fluid advection have been well established in deep marine sediments, but to date the K+ source required for the...
Article
Full-text available
Methane cold seep systems typically exhibit extensive buildups of authigenic carbonate minerals, resulting from local increases in alkalinity driven by methane oxidation. Here, we demonstrate that modern seep authigenic carbonates exhibit anomalously low clumped isotope values (Δ_(47)), as much as ~0.2‰ lower than expected values. In modern seeps,...
Article
Full-text available
Prevention of wellbore CO2 leakage is a critical component of any successful carbon capture, utilization, and storage program. Sporosarcina pasteurii is a bacterium that has demonstrated the potential ability to seal a compromised wellbore through the enzymatic precipitation of CaCO3. Here we investigate the growth of S. pasteurii in a synthetic br...
Article
Recent studies have suggested that the marine contribution of methane from shallow regions and melting marine terminating glaciers may have been underestimated. Here we report on methane sources and potential sinks associated with methane seeps in Cumberland Bay, South Georgia's largest fjord system. The average organic carbon content in the upper...
Article
Full-text available
Sporosarcina pasteurii is known to produce calcite or biocement in the presence of urea and Ca(2+). Herein, we report the use of novel ultramicrosensors such as pH, Ca(2+), and redox sensors, along with a scanning electrochemical microscope (SECM), to monitor a real-time, bacteria-mediated urea hydrolysis process and subsequent changes in morpholog...
Data
Recent studies have suggested that the marine contribution of methane from shallow regions and melting marine terminating glaciers may have been underestimated. Here we report on methane sources and potential sinks associated with methane seeps in Cumberland Bay, South Georgia's largest fjord system. The average organic carbon content in the upper...
Article
Full-text available
We investigated dissolved methane distributions along a 6 km transect crossing active seep sites at 40 m water depth in the central North Sea. These investigations were done under conditions of thermal stratification in summer (July 2013) and homogenous water column in winter (January 2014). Dissolved methane accumulated below the seasonal thermocl...
Article
Recognizing the importance of methane hydrate research and the need for a coordinated effort, the United States Congress enacted the Methane Hydrate Research and Development Act of 2000. At the same time, the Ministry of International Trade and Industry in Japan launched a research program to develop plans for a methane hydrate exploratory drilling...
Data
We investigated dissolved methane distributions along a 6 km transect crossing active seep sites at 40 m water depth in the central North Sea. These investigations were done under conditions of thermal stratification in summer (July 2013) and homogenous water column in winter (January 2014). Dissolved methane accumulated below the seasonal thermocl...
Article
Mass transport deposits (MTDs) in the Krishna-Godavari basin from the eastern Indian margin are common sedimentary features over the modern continental slope. Quantitative understanding of the scale and age of these MTDs is relevant to understanding their triggering mechanisms and environmental feedbacks, as well as for interpreting pore water chem...
Article
Full-text available
Hydroacoustic data document the occurrence of 5 flare clusters and several single flares from which bubbles rise through the entire water column from an active seep site at 40 m water depth in the central North Sea. We investigated the difference in dissolved methane distributions along a 6 km transect crossing this seep site during a period of sea...
Article
An extensive submarine cold-seep area was discovered on the northern shelf of South Georgia during R/V Polarstern cruise ANT-XXIX/4 in spring 2013. Hydroacoustic surveys documented the presence of 133 gas bubble emissions, which were restricted to glacially-formed fjords and troughs. Video-based sea floor observations confirmed the sea floor origin...
Article
We present a kinetic model based upon pore water data collected from eight sites drilled during the second Ulleung Basin gas hydrate drilling expedition (UBGH2) in 2010. Three sites were drilled at locations where acoustic chimneys were identified in seismic data, and the rest were drilled on non-chimney (i.e., background) environments. Our model,...
Article
The National Gas Hydrate Program Expedition 01 cored ten sites in the Krishna-Godavari basin, located on the southeastern margin of India. A comprehensive suite of pore water solute concentrations and isotope ratios were analyzed to investigate the distribution and concentration of gas hydrate along the margin, in situ diagenetic and metabolic reac...
Chapter
SynonymsCold vents;Methane seepsDefinitionCold seepage denotes the emission at the seafloor of deep-sourced fluids enriched in methane and hydrogen sulfide, which support a characteristic biome based on chemosynthetic organisms.Basic ProcessOxygen enters the ocean surface water through contact with the atmosphere. From there, dissolved oxygen is br...
Chapter
Methane and other low-molecular-weight gases, such as ethane and carbon dioxide, can combine with water to form ice-like substances at high pressure or low temperature in what are known as gas hydrates. The stability of these compounds is controlled by several factors including pressure, temperature, salinity, and gas concentrations. Gas hydrates a...
Chapter
Methane forms primarily from the breakdown of organic matter, which can be mediated by microbial activity or occur through thermochemical processes. Thus highest methane contents occur in rapidly accumulating sediments that underlie regions of high primary productivity, such as those bordering most continental margins. Methane in marine sediments o...
Article
During the Second Gas Hydrate Drilling Expedition in the Ulleung Basin (UBGH2), pore fluids were collected from sites that sampled sediments from the continental slope to the basin center, and included locations within and outside seismic identified chimney like features. At five non-chimney sites established during the UBGH2, discrete excursions t...
Article
shows usually minimum values at the Sulfate–Methane Transition Zone (SMTZ) at all sites. However, in chimney sites, these values have a much more depleted signature, indicating faster rates of methane consumption by Anaerobic Oxidation of Methane (AOM) supported by the higher methane flux. Moreover, here the massive hydrate that forms in shallow se...
Article
The concentrations of rare earth elements (REEs), sulphate, hydrogen sulphide, total alkalinity, calcium, magnesium and phosphate were measured in shallow (<12 cm below seafloor) pore waters from cold-seep sediments on the northern and southern summits of Hydrate Ridge, offshore Oregon. Downward-decreasing sulphate and coevally increasing sulphide...
Article
Full-text available
The significance of the various carbon cycling pathways in driving the sharp sulfate methane transition zone (SMTZ) observed at many locations along continental margins is still a topic of debate. Unraveling these processes is important to our understanding of the carbon cycle in general and to evaluate whether the location of this front can be use...
Article
We performed depressurization experiments on pressure cores (PCs) recovered from Holes UBGH1-10B and UBGH2-11B, which were drilled during two separate expeditions in the Ulleung Basin (UBGH1 and UBGH2). Various lines of evidence, such as convex curvature in the P–V curves obtained by depressurization, as well as X-ray images and resistivity-at-bit...
Data
We performed depressurization experiments on pressure cores (PCs) recovered from Holes UBGH1-10B and UBGH2-11B, which were drilled during two separate expeditions in the Ulleung Basin (UBGH1 and UBGH2). Various lines of evidence, such as convex curvature in the P-V curves obtained by depressuriza-tion, as well as X-ray images and resistivity-at-bit...
Article
During the 2nd Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) in 2010, gas-hydrate-bearing sediment cores were recovered at 10 drill sites. Base, on Infrared (IR) thermal image and grain-size analysis of the cores, three distinct types of gas hydrate are classified: Type I (fracture-filling in mud layers), Type II (disseminated in mud layers...
Article
We present results of a comparative study of hydrocarbons collected at acoustic chimney sites and nearby non-chimney (background) sites in the Ulleung Basin (offshore Korea). At all sites, molecular (C1/C2+ ratios ⩾ 600) and isotopic (δ13CCH4, δDCH4 and δ13CC2H6) indicators point to a microbial source of methane and ethane. Similarly, at all sites...
Article
Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern Cascadia mar...
Data
Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern Cascadia mar...
Article
Full-text available
Methane release from seafloor sediments is moderated, in part, by the anaerobic oxidation of methane (AOM) performed by consortia of archaea and bacteria. These consortia occur as isolated cells and aggregates within the sulfate-methane transition (SMT) of diffusion and seep-dominant environments. Here we report on a new SMT setting where the AOM c...
Article
Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern Cascadia mar...
Article
Full-text available
Since the report of the presence of brines associated with massive gas hydrate deposits on Hydrate Ridge (Oregon), there have been additional observations of pore fluids highly enriched in dissolved chloride at sites of massive gas hydrate occurrence in northern Cascadia accretionary margin (Canada), the Krishna-Godavari Basin (India) and the Ulleu...
Article
Transient hydrocarbon migration within a sediment package leaves behind robust geological signatures in the biogenic and authigenic carbonate record. Here we apply Flow-Through Time Resolved Analyses (FT-TRA) to unravel the compositional changes in foraminifera from coastal fossil methane seeps exposed from Oregon to Vancouver Island: The Eocene–Ol...
Article
Full-text available
We report on a bathymetric mapping and remotely operated vehicle surveys along the 100-600 m region offshore Oregon from 43°50'N to 44°18'N. We interpret our results in light of available geophysical data, published geotectonic models, and analogous observations of fluid venting and carbonate deposition from 44°30'N to 45°00'N. The methane seepage...
Data
Ocean drilling has revealed the existence of vast microbial populations in the deep subseafloor, but to date little is known about their metabolic activities. To better understand the biogeochemical processes in the deep biosphere, we investigate the stable carbon isotope chemistry of acetate and other carbon-bearing metabolites in sediment pore-wa...
Article
We investigated barium partitioning in a marginal basin where large barite structures occur associated with cold seeps on the San Clemente fault, off the coast of southern California. The barium flux to San Clemente basin sediments is two to three times greater than fluxes measured in surrounding California Borderland basins where there is no evide...
Data
Expedition 311 of the Integrated Ocean Drilling Program (IODP) to northern Cascadia recovered gas-hydrate bearing sediments along a SW-NE transect from the first ridge of the accretionary margin to the eastward limit of gas-hydrate stability. In this study we contrast the gas gas-hydrate distribution from two sites drilled ~ 8 km apart in different...
Article
Geochemical analyses of pore fluids collected from both non-pressurized and pressurized cores provide important constraints on the presence and distribution of gas hydrates in the Indian Ocean. Cores were recovered from two deepwater (900-1170 meter) basins offshore southeast India, the Krishna-Godavari (KG) (10 sites) and Mahanadi Basins (2 sites)...
Article
Deep subseafloor sediments with high concentrations of organic carbon and microbially-generated methane contain microbial communities that play an important role in the biogeochemical cycling of carbon. However, we still have a limited understanding of the fine (centimeter) scale sediment properties (e.g., grain size, presence/absence of hydrates)...
Article
Full-text available
Ocean Drilling Program (ODP) Leg 204 to Hydrate Ridge, located on the continental slope offshore Oregon (USA), was the first drilling expedition dedicated to understanding gas hydrate processes in accretionary complexes and provided a testbed for a number of different techniques for estimating the gas hydrate content of sediments. It was also the f...
Article
Because gas hydrate is preferentially enriched in the heavy water isotopes, the delta18O and deltaD values of pore waters collected from gas hydrate-bearing sediment can provide information on the abundance and mechanisms of gas hydrate formation. Pore waters sampled from deep-seated (40 to 125 mbsf) gas hydrate deposits in Hydrate Ridge during ODP...
Data
Isotopic characterization of carbon in the dissolved inorganic carbon (DIC) pool is fundamental for a wide array of scientific studies directly related to gas hydrate research. In order to generate integrated and internally consistent data of d13C of DIC in pore waters from Hydrate Ridge, we used the modern continuous flow technology of a GasBench...
Article
Full-text available
Hydrate Ridge is an accretionary thrust ridge located on the lower slope of the central Cascadia convergent margin. Structural mapping based on two-dimensional and three-dimensional multichannel seismic reflection profiles and gridded bathymetry coupled with deep-towed sidescan sonar data and Ocean Drilling Program (ODP) biostratigraphy suggests th...
Data
ODP Leg 204, which drilled at Hydrate Ridge, provides unique insights into the fluid regime of an accretionary complex and delineates specific sub-seafloor pathways for fluid transport. Compaction and dewatering due to smectite-illite transition increase with distance from the toe of the accretionary prism and bring up fluids from deep within the a...