2023-03-06T18:46:09.533

NotApplicable

2023-03-06T21:18:41.018

2023-03-08T18:02:05.431

NotApplicable

2023-03-08T20:11:47.431

Test dive to 500m for comms check of HFS and Methane Spectrometer. We will also be testing science sample logging.

2023-03-11T18:22:59

NotApplicable

2023-03-12T11:39:52.227

Dive one of FKt230303 for an exploratory dive to 1,900m. Vehicle has methane spectrometer, HFS, ORP and magnetometer.

2023-03-14T22:15:39.479

NotApplicable

2023-03-15T08:32:32.654

Launch target location: 23°32.9558’, -45° 08.9613’ Depth 2000m at the western base of steep scarp below summit WP2. 23° 33.0955’ -45° 08.0883 Summit peak ~1010m depth WP3. 23° 32.8641’ -45° 08.0302 Top edge of scarp south of summit WP4. 23° 32.7728’ -45 08.1092’ Base of scarp Main dive objectives: 1. Geological transect up the steep N-S trending scarp west of the summit peak, then south from the summit to the edge of a E-W scarp and down to the base of that, covering as much ground as possible while maintaining good visual contact and noting fauna along the route. Goal is to avoid long stops and keep sampling time to a minimum. Total distance from start to WP4 is 2.6km. 2. Collect HFS and Niskin samples for CH4/H2 analysis while moving (or very brief stop for Niskins) 3. Rock sampling at start/end, when good exposures are seen, and when hydrothermal alteration is seen. If rocks are dominantly basalt/volcanic, then collect less frequently. Prioritize ultramafics, if seen, and altered rocks. 4. Collect background DNA filter with HFS 5. If we happen to find visible hydrothermal flow, we will sample. Equipment: 1. HFS 2. Methane spectrometer 3. Niskins 4. 3 GTs on HFS 5. 2 quad rock boxes 6. 1 bio box with 2 compartments 7. High-T probe and suction sampler

2023-03-15T22:45:16.212

NotApplicable

2023-03-16T08:57:12.071

Exploratory dive at the 23N site of the Mid Atlantic Ridge with ROV SuBastian. The vehicle is carry Titanium gas tights, ORP, HFS and Magnetometer sensors.

2023-03-17T23:09:05.915

NotApplicable

2023-03-18T09:58:27.131

Launch target location: 23°32.454’, -45° 03.4416’ Depth 2200 at the base of a 200m scarp running N-S. This is the western end of the slope that we dove on in 493, where we sampled a peridotite rock on the eastern, low side. The scarp should expose more peridotite, and it is very steep, so should be nearly sediment free and may also host sessile fauna, similar to the 1000m scarp west of the summit peak. We will take advantage of this exposure to collect rock samples (this area has not been previously sampled. After reaching the top of the scarp, we will rapidly move from there towards the curved ridges at the detachment fault (one of our goals on dive 493). Are these ridges of talus accumulating in the saddle of the fault trace, or in-place erupted lavas, or something else? We are still looking for evidence of active or past hydrothermal fluid flow. We will take HFS samples for low-level hydrogen blank testing on the way to the bottom. ROV Niskins will be our primary sampler to collect near-bottom water for gas chemistry, and we need to start off taking those at regular intervals: at the base of the scarp, mid-way up the scarp, at the top, at the detachment fault at the base near the end of the dive. If we get good rock samples on the scarp face, we will go down the sedimented slope quickly and not stop until we get to the curved ridges, unless there are signs of hydrothermal activity. If there is still time, we will work south along the detachment fault. A revised base map from the latest AUV mission will be prepared and delivered before launch or during descent. Main dive objectives: 1. Vertical transect up 200m scarp, sampling rocks, observing animal communities. 2. Searching for signs of hydrothermal flow. 3. Collect Niskin samples for CH4/H2 analysis, stopping for Niskins. 4. Collect fluids from sediments using nozzle attachment for HFS intake 5. Collect background DNA filter with HFS Equipment: 1. HFS 2. Niskins 3. 3 GTs on HFS 4. 2 quad rock boxes, small bio-box, methane spectrometer. 5. 1 bio box with 2 compartments 6. High-T probe and suction sampler

2023-03-22T19:30:25.595

NotApplicable

2023-03-23T17:14:24.796

The starting location for the dive is -44 59.2003’, 23 28.4067’ bottom depth 3930m. This is a chimney identified from the very preliminary AUV dive data. We know the start point and will be making maps during the descent. More waypoints will be generated by the time we reach the seafloor. This will likely be a sampling dive on chimneys, assuming we find active vents, which is strongly indicated by the plume results and the AUV bathymetry. We would like to start the dive as soon as feasible. 1545 would be a good start time if that is not too soon. JRod estimates descent time at 3.5 hours. We will explore a line of features running along the steep wall SSE of the starting point, based on the first view of the AUV data.

2023-03-24T03:40:33.948

NotApplicable

2023-03-24T18:09:20.431

Exploratory dive around New Southeast Massif Vent Site

2023-03-27T22:28:53.376

NotApplicable

2023-03-28T15:47:50.123

Dive Goals: 1. Search for hydrothermal activity associated with mound structures 2. If active vents are found, sample for chemistry, biology, geology 3. Characterize the nature of the mound structures, video and sampling 4. Survey scarp where peridotites were sampled by IFREMER dredge; sample rocks 5. Survey unexplained terrain below the scarp HFS note: bags 16, 17, 18 filtered; all other bags and pistons unfiltered; LVB is on 9; no sampler on 8; chem filters 10 and 11 (take at least one this dive); RNA filters 12-15 (take 1 eDNA sample if fauna sampling happens).

2023-03-29T21:18:34.727

NotApplicable

2023-03-30T11:21:47.079

Dive Site: 24.95984°N 45.5749°W, Depth: 3790m The first dive at the Swarm vent did not take enough chemistry samples and we need to get replicates for fluid/gas chemistry from two sites. Additional bio sampling is also a priority. This will be primarily a sampling dive. When the sampling needs have been met at the vent, we will look for representative volcanic rock samples nearby and some reconnaissance to look for other rock types. Perform magnetometer calibration at 2000 m depth. Stop the winch, 360 turns both directions. Resume descent and repeat 360 turns while descending. If time permits, do this procedure on the ascent as well. (Magnetic rocks collected may alter the signature of the ROV). Land 50 m away from the vent site. Use Nav and sonar to locate the vent. View the vent from the approach, getting a view of as many sides as possible. Go to the site where the ROV did the high-T fluid sampling on S497. Take ROV high-T probe temperature measurement. Set up with HFS and take multiple replicates: 3 bags, 3 pistons, 3 gas-tights (2 HFSGT, 1 hand-held unless view of vent source is completely obstructed). If any HFS samples are suspected to not have filled, take an extra sample of the same type. Reserve 2 gas-tights for the second site. If possible, take a GEO sample of chimney. The high-T samples take approximately 5 minutes each. When finished with the chemistry sampling, biology team will collect black gastropod and polychaete worm samples from the chimney surface with the suction sample. While the suction sampling is happening, we will collect a sample for eDNA using RNA Filter 10 on HFS for Sean. When the first high-T site is finished, move around to another side of the chimney and find a second high-T site for setup. Repeat same process as at first site (3 pistons, 3 bags, 2 gas-tights) in high-T fluid. Take active chimney sample if possible. When second high-T site is finished, find a diffuse venting site for microbiology sampling. Fill large volume bag, plus 2 or 3 filters. These take 15-20 minutes each. If there are bags or piston samplers remaining, take them at the diffuse vent. If there are specific biology sampling needs, finish those. Place a second physical marker on the opposite side of the vent from the first marker. When vent sampling is done, search around the vent site for volcanic/intrusive rocks and collect. We need samples of the rock underlying the vent site. If there are nearby fault scarps, go to them and look for in-situ rocks to collect. The ROV needs to be on deck 1 hour before the AUV is due at the surface (so estimated on deck by 0800, off bottom by ~0500 or earlier). Leave 10 minutes time for a magnetometer calibration on the way up at 2000 m (stop, 360 both directions, resume ascent, 360 both directions).

2023-03-30T15:43:16.635

NotApplicable

2023-03-31T07:09:14.52

General Goal of ROV Dive S0499 is to understand the stratigraphy of exposed units at GrappeDeux in the vicinity of the large landslide scarp and peridotite samples collected by IFERMER. On Bottom Location – Explore the nature and make up of seafloor on down dropped side of landslide scarp. What are block scarps composed of? Take in-situ samples if possible. Bottom Location to WPT1 – Traverse blocky, chaotic side of landslide scarp and move west to the landslide scarp and evaluate and sample the make-up of the scarp outcrop. Take in-situ samples if possible. WPT1 -> WPT2 – Move past headwall scarp of landslide and investigate mound structure on west side of scarp. WPT2 -> WP3 – Continue west to evaluate next headwall scarp. This headwall scarp is more subtle/muted on the seafloor and could be sedimented. Don’t spend to much time at this location if outcrops are not visible. WPT3 -> WPT4 – Move to SE to evaluate another isolated mound structure. Is this a pillow mound? with hydrothermal alteration? or something else? Take in-situ samples if possible. WPT4 -> WPT5 – Move to the NW to investigate another scarp. This is the side of a more narrow landslide scarp that may represent the next stratigraphic unit above the previous scarp outcrop. Take in-situ samples if possible. WPT5 -> WPT6 – Explore to NW. Smooth seafloor. What is the nature of this smooth seafloor and is its lithology discernable? Don’t feel the need to get all the way to WPT6. If you feel that the seafloor has been characterized move on to WPT7. WPT6 -> WPT7 – Back to SW along the last headwall scarp. This is where IFERMER dredging reported peridotites recovered. Find peridotite and/or other rocks exposed and sample. Take in-situ samples if possible. WPT7 – WPT8 – Move to NW. Traverse steep/exposed scarp that trends to the NW from previous location. What is the lithology of this outcropped unit. Take in-situ samples if possible. WPT8 – WPT9 - Move to NW. Traverse steep/exposed scarp that trends to the NW from previous location. What is the lithology of this outcropped unit. Take in-situ samples if possible. WPT10 – WPT11 – Move to N. Investigate elongated (NNW-SSW, N-S) elevated seafloor. Take in-situ samples if possible. WPT11 – WPT12 – Move to W. Stretch goal of ROV dive. Investigate changes in lithology as the ROV moves slowly uphill making notes of lithologic changes notable changes in seafloor characteristics.

2023-04-02T05:20:50.874

NotApplicable

2023-04-02T20:12:37.03

Overall priority for this dive, and for Puy des Folles, is to verify that there are multiple, active hydrothermal sites, and to collect essential samples to characterize their chemistry and biology. We have the AUV map of nearly the entire volcano summit, and finishing the last unmapped portion with an AUV mapping dive is another high priority. The AUV map is the primary geological data that we need to understand this volcano. The ROV dives will provide ground truth video observations of the terrain to allow confident interpretation of the AUV map. This includes verifying active and inactive vent structures, lava morphologies and relative ages, and volcanic rock samples at key locations. Until we find active vents and sample them, we have no idea what the animal communities are, or what the fluid chemistry is, so the top priority is visiting as many hydrothermal chimney target sites as possible and getting the basic chemistry and biology data. The only way to understand the vent fluid chemistry and biology is to take samples, and that is the highest priority for the ROV at Puy des Folles. Launch site: 45 39.070266 W Lat: 20 30.933439 N Depth: -1967.506 m Main target: NW Chimney Group Equipment: HFS w/ 3 Gas-tights, 2 gas-tights on front porch, methane spectrometer, Niskins, suction sampler. (Note: if the problem with fiber optic comms for the spectrometer can’t be fixed before dive time, we will pull the spec from the ROV and fix the issue after this dive. This assumes that the fiber problem does not affect anything else.) Schedule: 0200 Launch ROV See waypoints after map. 0300 Magnetometer calibration 360s at ~1000 meters 0400 ROV on bottom at base of scarp, wp0. Start 2 hour geology transect. 0600 ROV arrives at southern end of the vent field, roughly 140mx100m, with 10 chimney spires ranging from ~5m tall to 12m tall. Dave B will take over watch lead at this time, when the ROV is approaching wp9. The first vent to see is at waypoint 9. Keep to the east of it as we track north and look left/west while moving north to go past the other chimneys at wp 8, 7, 6, 5 and keep east of the structures until arriving at wp4, the tallest chimney in NW cluster. Assuming that this structure is hydrothermally active, we will start video and sampling here. Note which of the chimneys at wp 5-8 are active and might be good second sampling targets. Video transect up and down chimney up to 1 hour for photogrammetry. Dive 500 Flag photo op. Select chemistry sampling targets (high-T and diffuse) during video transect. Start with high-T sampling site. Temp measurement with High-T probe, 10 minutes. Put away and set up HFS sampling (up to 30min). Preference for site that is low relative to the porch so that we can take samples above the vent with the HFS nozzle for Cecile’s metal sulfide particle formation study. Collect a piece of the active chimney (15 mins). Collect two bags and two pistons from the high-T vent (15 min). Collect two gas-tights (HFSGT, 5 minutes). If Tamara wants, collect a hand-held gas-tight (15 minutes). Check high-T probe measurement again at end of sampling. Next do smoker particle sampling with HFS at approximately 10cm, 30cm, and 50cm above the vent orifice. (Valve positions 1, 2, 3 with filtered bags). Each sample takes 10 minutes for positioning and pumping, 30 minutes total. When done sampling at the vent, rise up and take 3 Niskins in the plume above the vent. Estimated total time for temperature, fluid, smoke, and chimney sampling at hot vent is 2.5 hours. Move to diffuse sampling site. Use High-T probe to check temperatures (10 min). Set up with HFS to collect microbiology/chemistry samples. Take large volume cylinder/bag sample (20min), and two filters (35 min for 2). Take HFS bag and piston samples for diffuse chemistry (10 min). Total time for diffuse setup and sampling 90 minutes. Choose biology sampling site. While collecting bio samples with the suction sampler, collect RNA filter 10 for Sean for eDNA. Sampling time for biology 60-90 minutes. Target species are gastropods, possibly mussels, and other fauna. Collect a piece of old, inactive sulfide from the base of the chimney structure. 15 minutes. Approximate sampling time at large smoker chimney: 5-6 hours. Approximate time after sampling first chimney: noon. Next, if one of the chimneys seen on approach to wp5 looks like a good sampling site, go to it, take a quick video overview, and choose a sampling spot. Collect high-T and diffuse fluid samples at the second sampling site, in similar way to the first sampling site, but without the smoke particle sampling. Before ending the dive, fly by all the chimneys at waypoints 10-13. If any are notably different from the other chimneys, get some close-up video. Depending on time, consider sampling. ROV should be on deck by 1900. AUV launch will follow this dive, and the ROV will be setup for the next dive. ROV setup for the next dive depends on how equipment works on this dive. Timing of next ROV dive is controlled by the AUV launch and recovery, as in many previous dives, so S501 will be approximately 12-15 hours total.

2023-04-03T18:33:26.289

NotApplicable

2023-04-04T09:56:43.19

Our plan is to start at the large active chimney, take chemistry and biology samples as efficiently as possible, then go by 17 more waypoints through the dive, looking for other active chimneys. If found, we will sample (at least some of) the other active chimneys. The end time for this dive is not yet set, but possibly around 0600 tomorrow. We would then turn around the ROV and partially reload for fluid sampling and put in the last ROV dive in the afternoon. That dive will go overnight and come on deck in the morning in time to start transit back to Puerto Rico. Both dives include seeing as many chimney structures as possible and also fast traverses over the volcanic terrain to match to the AUV map.

2023-04-04T17:54:34.416

NotApplicable

2023-04-05T10:16:01.466