2026-05-21T22:24:40.227

NotApplicable

2026-05-22T21:12:45.575

This ROV dive will visually inspect and sample the ITR1 target area on the I1615 middle escarpment/intra-transform ridge flank of the Doldrums Transform Margin. The dive will follow up on the AUV survey of the same area, which mapped water depths of approximately 2,000- 4,500 m and targeted escarpment morphology, lineaments, slope breaks, talus fields, basement highs, sediment pockets and sediment-basement contacts. The site is a priority because previous work indicates an altered and deformed gabbro dolerite-ultramafic association, making it well suited for testing links between basement exposure, faulting, lithological variability, alteration, fluid circulation and possible habitat development. The ROV dive will ground truth ship-based and AUV-derived bathymetry, backscatter, sub-bottom and environmental anomalies, and identify evidence for exposed basement, volcanic or intrusive lithologies, fault-related deformation, alteration, mineralisation, seepage indicators, sediment accumulation, and potential biofilms and chemosynthetic communities.The dive will prioritise high-quality video documentation along at least three 20 minute long transects, as well as close-up imaging, rock, water and biological sampling, and push coring where sediment is present.

2026-05-23T22:01:38.001

NotApplicable

2026-05-24T21:24:07.327

This ROV dive will visually inspect and sample a sedimentary basin-to-flank transition in the Doldrums Transform Margin, with the transect designed to move from sedimented basin terrain onto the adjacent flank containing the S45-13 sample location. The dive is primarily designed to test whether the strongest geochemical, sedimentological or biological indicators of fluid flow occur at sediment-basement boundaries, sediment pinch-outs, basin margins or basement highs. The dive will ground-truth AUV-derived bathymetry, backscatter, sub-bottom and environmental data. It will document sediment character, sedimentary structures, slope transitions, outcrop exposure, talus, basement lithology, alteration, mineral staining, possible carbonate or mineral crusts, microbial mats, unusual faunal aggregations and any direct or indirect indicators of seepage or diffuse venting. The dive will prioritize push coring across the basin-to-flank transition, close-up imaging of sediment-basement contacts, and targeted rock sampling from the flank, especially near S45-13 or comparable exposed basement.

2026-05-25T11:58:36.278

NotApplicable

2026-05-26T11:52:55.429

This ROV dive will visually inspect and sample an upslope transect along the southern flank of Peyve Seamount, a prominent structural high on the northern side of the Vernadsky transform. The dive is designed to move from the lower southern flank upward across steep faulted terrain, exposed basement, talus fields, possible terraces and slope breaks toward shallower parts of the seamount. The main scientific objective is to determine whether the southern flank exposes deformed lower- crustal or mantle-derived rocks, and whether these rocks show evidence for hydrothermal alteration, serpentinisation, mineralisation, carbonate or mineral crusts, or other indicators of past or present fluid circulation. The dive will also document how substrate type, alteration, sediment cover and biological communities change with elevation along the flank. The dive will ground-truth mapped bathymetric features and previous dredge-based interpretations from Peyve Seamount. Particular attention will be given to steep scarps, fault-controlled ledges, talus accumulations, fractured outcrop, vein-bearing rocks, orange/red/yellow alteration, black or white mineral coatings, possible sulphide-like staining, ferromanganese crusts, microbial mats, unusual faunal aggregations, and any direct or indirect evidence of seepage or diffuse venting.

2026-05-28T11:34:54.991

NotApplicable

2026-05-29T11:12:31.254

This ROV dive will investigate potential hydrothermal venting targets identified from the preceding AUV survey within ITR1. The dive will ground-truth areas where AUV bathymetry, backscatter, water-column observations and environmental data suggest possible active or recent fluid flow. These include local turbidity anomalies, temperature or potential-temperature anomalies, oxygen depletion relative to depth, unusual seafloor backscatter and morphology, flares in water column data, fractures and lineaments. The main scientific objective is to determine whether the mapped anomalies correspond to active hydrothermal venting, diffuse seepage, recently active hydrothermal sites, or altered/mineralised seafloor associated with past fluid circulation. This dive will help test the expedition’s broader hypotheses that fluid flow in the Doldrums Transform system is focused by basement structure, fault damage zones, intra-transform ridge morphology, lithological contrasts, and sediment cover. The dive will prioritise careful visual ground-truthing of the AUV-derived targets while retaining flexibility to follow real-time observations and sensor anomalies. If active venting or strong evidence of hydrothermal discharge is encountered, the dive will focus on detailed imaging, environmental observations, and targeted sampling around the discharge site, adjacent altered areas, and nearby background seafloor.

2026-05-30T20:19:02.106

NotApplicable

2026-05-31T16:09:19.177

This ROV dive will visually inspect and sample the southern flank of the Doldrums Transform system. The dive is designed to ground-truth AUV mapping and environmental sensor observations from the southern flank, with particular emphasis on the transition between sedimented terrain, exposed or shallowly buried basement, faulted slopes, scarps, basement highs, and possible zones of fluid discharge or hydrothermal alteration. The southern flank is scientifically important because previous sampling and mapping indicate that it may expose lithologies and structures favorable for deep fluid circulation, including fractured basement and possible ultramafic or mafic rocks. The dive will document seafloor morphology, substrate type, sediment cover, outcrop character, talus, fractures, veins, mineral coatings, alteration colours, possible sulphide or oxide staining, microbial mats, unusual faunal aggregations, and any direct or indirect indicators of seepage or hydrothermal discharge.

2026-06-02T18:24:59.091

NotApplicable

2026-06-03T00:29:26.128

This ROV dive will visually inspect and sample priority targets identified during AUV Dive E00015 on the intra-transform ridge between the northern and southern flanks of the Doldrums Transform system. The dive is designed to ground-truth high-resolution AUV bathymetry, acoustic backscatter, sub-bottom profiler, HiSAS and environmental sensor observations across a structurally complex ridge domain characterised by intense deformation, faulting, fracturing, basement exposure and possible high-permeability pathways for fluid circulation. The target area is scientifically important because it encloses dredge sites S09-76 and S09-81, where peridotite was recovered. This indicates exposure of mantle-derived rocks and raises the possibility that ultramafic basement, serpentinisation reactions, fault damage zones and sediment–basement transitions may be linked to hydrothermal or diffuse fluid discharge. The dive will therefore focus on documenting the relationship between structural deformation, substrate type, alteration, mineralisation, sediment cover, biological communities and any direct or indirect indicators of fluid flow. The ROV will inspect ridge crests, ridge flanks, scarps, lineaments, basement highs, sediment pockets, sediment–basement contacts, mass-wasting features and areas of anomalous AUV backscatter or environmental sensor response. Particular attention will be given to exposed or shallowly buried basement, fractured rock, veining, alteration colours, sulphide-like staining, oxide or ferromanganese coatings, microbial mats, unusual faunal aggregations, reduced sediments, crusts, and any evidence for active or recent fluid discharge. The dive will collect representative rock, sediment, biological and water samples where appropriate, with the aim of testing whether the intra-transform ridge acts as a focused pathway for fluid circulation within the Doldrums Transform system.

2026-06-03T01:59:25.608

NotApplicable

2026-06-03T18:09:44.99

This ROV dive will visually inspect and sample priority targets identified during AUV Dive E00015 on the intra-transform ridge between the northern and southern flanks of the Doldrums Transform system. The dive is designed to ground-truth high-resolution AUV bathymetry, acoustic backscatter, sub-bottom profiler, HiSAS and environmental sensor observations across a structurally complex ridge domain characterised by intense deformation, faulting, fracturing, basement exposure and possible high-permeability pathways for fluid circulation. The target area is scientifically important because it encloses dredge sites S09-76 and S09-81, where peridotite was recovered. This indicates exposure of mantle-derived rocks and raises the possibility that ultramafic basement, serpentinisation reactions, fault damage zones and sediment–basement transitions may be linked to hydrothermal or diffuse fluid discharge. The dive will therefore focus on documenting the relationship between structural deformation, substrate type, alteration, mineralisation, sediment cover, biological communities and any direct or indirect indicators of fluid flow. The ROV will inspect ridge crests, ridge flanks, scarps, lineaments, basement highs, sediment pockets, sediment–basement contacts, mass-wasting features and areas of anomalous AUV backscatter or environmental sensor response. Particular attention will be given to exposed or shallowly buried basement, fractured rock, veining, alteration colours, sulphide-like staining, oxide or ferromanganese coatings, microbial mats, unusual faunal aggregations, reduced sediments, crusts, and any evidence for active or recent fluid discharge. The dive will collect representative rock, sediment, biological and water samples where appropriate, with the aim of testing whether the intra-transform ridge acts as a focused pathway for fluid circulation within the Doldrums Transform system.

2026-06-03T21:13:07.347

NotApplicable

2026-06-04T22:19:34.291

This ROV dive will return to the active hydrothermal vent field discovered during Dive S0926 on the western flank of ITR1 in the Doldrums Transform system. The previous dive confirmed the presence of active and inactive hydrothermal chimneys, black-smoker and diffuse discharge, mineralised and altered substrates, vent-associated fauna, and sedimented areas suitable for push coring and pore-water sampling. The original S0926 dive plan focused on ground-truthing AUV-derived hydrothermal targets using visual observations, environmental sensing, fluid/water sampling, push cores, rock/mineral sampling, and biological documentation. The purpose of this return dive is to carry out more systematic characterisation of the vent field and adjacent seafloor. The dive will prioritise: detailed imaging and photogrammetry of active and inactive chimneys; targeted rock and mineral sampling; push coring of vent-proximal and background sediments; collection of vent-proximal and background water samples using Niskin bottles; sediment or mineral scoops where appropriate; and documentation of biological communities associated with active flow, diffuse flow, inactive chimneys, altered crusts, and background substrates. The dive will begin south of the vent field and proceed into the known working area. Sampling and imaging will be adjusted in real time based on vehicle safety, visibility, biological sensitivity, substrate suitability, and the occurrence of active flow, chimney structures, sulphide-like material, altered rocks, stained sediment, microbial mats, and vent-associated fauna.

2026-06-06T09:58:42.311

NotApplicable

2026-06-07T09:49:36.338

This ROV dive will investigate the neo-volcanic zone surveyed during AUV Dive E00016 on ITR1, east of the E0013 survey area. The dive will ground-truth AUV-derived targets associated with young volcanic terrain, including flat-topped mounds, volcanic cones, lava-flow surfaces, flow fronts, volcanic ridges, fissures, collapse scarps, fault scarps, sediment pockets, sediment–basement transitions, and high-backscatter or texturally anomalous seafloor. The main objective is to move from east to west across the neo-volcanic zone and then continue up the western flank, documenting changes in volcanic morphology, substrate type, sediment cover, structural deformation, alteration, and potential evidence for active or relict hydrothermal circulation. Particular attention will be given to mound summits and flanks, fissures, collapse features, flow fronts, sediment-free or lightly sedimented lava surfaces, fractured basement, talus, stained sediment, mineralised or altered rock, microbial mats, shimmering water, and any vent-associated fauna. The dive will prioritise visual observations, high-definition video and still imagery, targeted rock sampling, opportunistic sediment push coring where suitable sediment is present, water sampling where hydrothermal or diffuse-flow indicators are observed, and detailed documentation of any environmental anomalies. Sampling and the exact route will be adjusted in real time based on vehicle safety, visibility, slope angle, biological sensitivity, substrate suitability, and the occurrence of active flow, altered substrates, sulphide-like material, sediment-basement contacts, or other features of scientific interest.

2026-06-08T15:20:53.924

NotApplicable

2026-06-09T09:57:03.303

This ROV dive will visually inspect and sample the fracture-zone terrain east of the main Doldrums Transform system, with the objective of testing whether fluid-flow indicators, altered basement, mineralisation, diffuse venting, or hydrothermal deposits extend eastward away from the intra-transform ridge and into the adjacent fracture-zone domain.The preferred target is the southern flank of the fracture zone, because it lies closer to the intra-transform ridge and is therefore more likely to preserve structural, lithological and hydrothermal continuity with the previously investigated vent-bearing terrain. The dive will examine whether the fracture-zone flank contains exposed basement as documented in a previous S06 dredge cruise, fault scarps, talus, fracture networks, sediment-basement contacts, altered rocks, mineral staining, crusts, microbial mats, unusual faunal aggregations, or direct evidence of low-temperature seepage or hydrothermal discharge. The dive will combine broad visual reconnaissance with targeted close-up inspection, rock sampling, push coring, water sampling and quantitative visual transects.

2026-06-09T14:24:49.309

NotApplicable

2026-06-10T10:12:44.3

This ROV dive will visually inspect and sample the large landslide scar surveyed during AUV dive E00017 on the southern flank of the Doldrums Transform. The dive will run from the base of the slope to the upper part of the scar, crossing the full landslide morphology from the lower depositional/scarp-base area, across the main scarp face, and up to the scar crest and adjacent upper-slope terrain. The main objective is to determine whether the landslide scar exposes basement, faulted or fractured hard substrate, sediment-basement contacts, altered rocks, mineral staining, hydrothermal or authigenic crusts, microbial material, unusual faunal aggregations, or active/diffuse fluid-flow indicators. The AUV plan for E00017 identified the western scarp of the large scar as a target for mapping exposed basement, fault planes, fractures, benches, terraces, and possible fluid-flow pathways.

2026-06-12T11:25:53.155

NotApplicable

2026-06-13T16:15:22.161

This ROV dive will investigate two potential hydrothermal targets identified from water-column data and AUV environmental sensor anomalies. The targets occur along the flank of the study area and area defined by spatially coherent anomalies in methane, turbidity, dissolved oxygen, and CTD-derived temperature/salinity/conductivity structure. The dive will visually inspect the highest-priority anomaly areas and then cross the flank to assess whether the water-column and near-bottom environmental signals are associated with active hydrothermal venting, diffuse fluid flow, inactive hydrothermal deposits, altered basement, mineralised substrate, fault/fracture-controlled permeability, or non-hydrothermal water-mass and sediment resuspension effects. The dive will combine targeted inspection of these two anomaly centres with a geological traverse across the flank. The main objective is to determine whether the environmental anomalies are linked to specific seafloor features such as fault scarps, fissures, fractures, ridges, lineaments, rough basement highs, hydrothermal mounds, collapse structures, altered rock, mineral staining, Fe-Mn or sulphide crusts, sedimented hydrothermal material, microbial mats, unusual faunal aggregations, or visible fluid flow indicators.