Deployment: AT26-23_Alvin_Dives

[DMO NOTE-This deployment was added for Costa Vetriani's 'chemosynthetic biofilm diversity' dataset but then he asked to have it removed.  I'm leaving it here in case he submits data for these dives in the future. - njc, 2015-02-10]

The Alvin dives of cruise AT26-23 (dive numbers 4761 through 4774) are listed below, with dive members and synopses.  All took place in the East Pacific Rise hydrothermal vent area.

Alvin Dive    Pilot    Observers     Synopsis

Dive:    4761
Pilot:    Bob Waters
Observers:    Stefan Sievert, Jesse McNichol
Synopsis:    Dive started a Pvent, where pieces of fresh chimney were collected. Temperature was measured at 325ºC. We proceeded to check on the larval colonization site of Lauren Mullineaux close to Pvent (bucket lid marker O). Took photos and video. Proceeded north to Crab Spa area. We deployed two colonizers at Riftia colony below Crab Spa, one in diffuse 30ºC flow, one away from venting. Collected water samples with sippers in Riftia colony and collected Riftia of various sizes. We then took four IGT samples at Crab Spa, and fired Niskin off axis before ascending.  

Dive:    4762
Pilot:    Bruce Strickrott
Observers:    Katie Scott, Jefferson Grau
Synopsis:    We were tasked with collecting a black smoker from Bio9, Riftia, and 4 IGT samples at Crab Spa. On the way down, the starbourd thruster developed a ground fault. Based on diminished maneuverability we decided to punt on the black smoker collection and move on to the water sample and Riftia collections. We cruised to Crab Spa, where we took four IGT samplers at 18-32C from the shimmering water emerging from the top of the feature. From there, we went to the base of the feature where there is a large Riftia clump. We temperature-probed the clump, collected four water samples using the Wheat squeezer samplers, and collected many small Riftia from the clump. Bruce trained Jefferson how to collect Riftia without damaging them, and Jefferson did a great job with this. We still had a little time, so we cruised toward Bio9 to perhaps collect a smoker, but ran out of time before we found a suitable smoker to collect. It was a very successful dive.  

Dive:    4763
Pilot:    Phil Forte
Observers:    Craig Taylor, Jeremy Rich
Synopsis:    The first item of business was the deployment of the Vent-SID, that was deployed to the bottom within ~50 m of the sampling site via hydro-wire the night before. The instrument was brought to a site (x-4575 y-78160) that had a crack in the sea floor that was emanating vent fluids at about 40 C. The instrument umbilicus wand was inserted into the crack and the instrument initiated for automated sampling and tracer incubations (19:02 GMT). IGT #6 and #4 were fired at the Vent-SID sampling sight to obtain chemistry and gas samples (17:56, 18:07 GMT for IGT 6 & 4, respectively). Alvin motored to Crab Spa to obtain fluid samples, IGT #'s 2 and 5 (x-4598 y-78148, temp 23-24C. 19:32 & 19:44 GMT, IGT 2, 5 respectively. About 30 mussels were collected at Crab Spa and stored in BioBox (x-4600 y-78150, temperature at sampling site ranged between 4.5-6.0C. 20:00 - 20:05 GMT. Bacterial colonizers (#CV-84 & 85) were placed in a well developed bed of Riftia (x-4595 y-78163), temperatures above the colonizers fluctuated substantially and ranged between 8-12C. 20:16 - 20:20 GMT. Alvin motored to Bio 9 black smokers to collect 2 chimney samples that were deposited in separate small bioboxes. Chimney material with low numbers of Alvanella worms was collected (x4617 y-77996), highest temperature of the fluids exiting the chimney was 361C. 20:48 GMT. A second chimney sample, densely populated with Alvanella was collected (x-4619 y-77984), max temp of emanating fluids, 271C. 21:06 GMT. A niskin bottle was tripped off axis, x-4642 y-77976. 21:18 GMT.  

Dive:    4764
Pilot:     Bob Waters
Observers:    Jeff Seewald, Fengping Wang
Synopsis:    After arriving at the bottom on the western side of the ASC we transited to the Riftia patch near Tica to release the VENT-SID. This was followed by a transit to Bio9. Once at Bio9 we measured temperature with the Alvin T-probe and then collected chimney material. High temperature fluid was collected in a tedlar bag using the SIP for 30 minutes. This was followed by collection of two high temperature fluid samples using isobaric gas-tight samplers. Transited back to the riftia patch while taking a few detours to survey the area. Collected riftia at the riftia patch. Moved to the Crab Spa area where we collected basalt substrate that was bathed in diffuse fluid from a structure located few meters way from the Crab Spa vent. Another quick survey of the Tica area before returning to Crab Spa to collect the final two isobaric gas-tight fluid samples. Transited back to Bio9 to collect more fluid in the tedlar bag using the SIP. Moved off axis before tripping the Niskin bottle.  

Dive:    4765
Pilot:     Bruce Strickrott
Observers:    Horst Felbeck, Donato Giovanelli
Synopsis:    We landed a short distance away from Bio9. Deployed two CV colonizers at two different places. Deployment was difficult because of weight problems with the colonizers. Temperatures were measured before and after deployment. Moved to the Vent-SID deployment site and inserted a third colonizer into the crack were the VENT-SID wand was used. Temperature was taken. Small Riftia were collected close by in a large Riftia clump. A few larger Riftia were collected afterwards. Transited to Crab Spa. Because of problems inserting the IGT wand, a loose rock with animal growth was removed from the entry of the outflow and collected. 4 IGT samples were taken. We proceeded south to look for colonizing plates that had been left in January 2014 but did not find any. Proceeded to P-vent and surveyed. Went a short distance off axis and collected two basalt samples. Triggered Niskin bottle and dropped weights.  

Dive:    4766
Pilot:     Phil Forte
Observers:    Jefferson Grau, Sean Sylva
Synopsis:    We landed to the West of the ASC and transited to Bio9. Once there we collected a high temperature fluid into a Tedlar bag with the SIP sampler for 30 minutes. Next we moved over to P-Vent and collected a chimney sample. Moved over to Vent SID site and collected a chimney with Alvinella on the back side of Riftia Patch. This was followed by collection of two high temperature fluids with isobaric gas-tight samplers. Collected Riftia at the Vent SID/chimney site. Moved to Crab Spa and collected two fluids with isobaric gas-tight samplers. Continued our search for small to medium Riftia at Tica and other patches we came across. Transited off-axis and collected bottom seawater in the Go-Flo bottle.  

Dive:    4767
Pilot:     Bob Waters
Observers:    Stefan Sievert, Sayaka Mino
Synopsis:    We started the dive by finding the Vent-SID, which had been wired down the night before. We quickly found the instrument and then moved to the deployment site about 30 m away. The Vent-SID was quickly positioned by pilot Bob Waters, and we then looked for a suitable location to insert the wand in a crack emanating hydrothermal fluids. Finding the right spot was greatly aided by having real-time temperature data from the tip of the wand by using an ICL. We found a spot that was around 40ºC warm and proceeded to start the instrument. We then moved to the L-O bucket lid marker site close to Pvent to recover and deploy larval colonization panels, also known as 'sandwiches', for Lauren Mullineaux. Temperature at base of sandwiches was measured before recovery and after deployment of new ones. Afterwards, we collected a piece of black smoker chimney at Pvent and fired 2 IGTs. We then proceeded to Crab Spa where two IGT samples were taken. We also sampled pieces of basalt covered with biofilm and animals. We then moved off-axis and fired a Niskin before ascending.  

Dive:    4768
Pilot:     Bruce Strickrott
Observers:    Jeff Seewald, Jessica Panzarino
Synopsis:    After arriving at the bottom on the western side of the ASC we transited to the Riftia patch near Tica to release the VENT-SID. Two fluid samples were collected from Riftia crack where the VENT-SID had been deployed. Riftia were then collected in the general vicinity of the Riftia patch/Tica along with fluids samples in Wheat-style syringe samplers. Transited to Crab Spa where two fluid samplers were collected in isobaric gas-tight samplers. Moved to the summit of Tica to image previously deployed microbial colonizers. Headed south to Bio9 where a high temperature chimney sulfide was collected along with a piece of sulfide that was not in contact with active fluid flow. Moved off axis before tripping the Niskin bottle.  

Dive:    4769
Pilot:     Phil Forte
Observers:    Stefan Sievert, Camila Signori
Synopsis:    We landed off-axis to the west of the axial trough. We proceeded to LVP landing site, picked up LVP, and positioned it next to Crab Spa. We then moved south to Bio9 to pick up two CV colonizers (CV 86, 87). After picking up both colonizers, we moved back to Crab Spa area, took an IGT sample in the Riftia crack (45ºC), and picked a number of Riftias at a low activity site nearby (temperature was just a little bit over ambient). We then proceeded to recover CV 88 in Riftia crack. Moving on to Crab Spa we took 3 IGTs (~25ºC), positioned the wand of the LVP at Crab Spa, and took a SIP sample (pumping for 50 min). We ended the dive by taking a Niskin off-axis.  

Dive:    4770
Pilot:     Bob Waters
Observers:    Chris Lathan, Sean Sylva
Synopsis:    We landed on bottom and transited to Crap Spa. Once there we released the Large Volume Pump. Next we moved over to Tica to recover CV84 located in a clump of Rifta. We then transited to Flea Vent. Once at Flea Vent we collected two fluids with isobaric gas-tight-samplers. We transited back to Crap spa where we collected two more fluid samples with isobaric gas-tight samplers. Next we collected a low temperature fluid, at Crab Spa, into a Tedlar bad with the SIP sampler. We moved off-axis and collected bottom seawater with the Go-flo bottle.  

Dive:    4771
Pilot:     Bruce Strickrott
Observers:    Scott White, Avery Lee
Synopsis:    Dive Synopsis Alvin 4771 11/16/14 There was a problem with FrameGrabber, so there are no pictures and no data for this dive's Framegrabber.

Off-axis exploration of the a string of small volcanic mounds overlying a melt lens detected seismically (http://dx.doi.org/10.1016/j.epsl.2013.12.040 ) followed a ~3 km track from east to west toward the spreading axis of the East Pacific Rise, about 5 km away. Alvin landed on seafloor of large pillow outcrops amid pockets of sediment, and took one rock and one sediment core (core barrel 6). Proceeding upslope and north, the sediment grew thicker so another sediment core was taken (core barrel 5). Alvin then proceeded to the top of a low ridge, having ascended 20 m over 300 m, we turned west. Farther along by 200 m, pillows turned into lobate lava and another rock sample was taken. Alvin continued west returning into pillow lava and back into lobate lava where another rock sample was taken. The track turned to the north, skirting the base of a 60 m high volcanic mound, stopping 500 m farther along for a sample of sheet lava and sediment core (barrel 9). Alvin turn south, upslope, to the mound summit stopping at mid-way for another pillow lava sample. At the summit, 3 rock samples and 3 sediment cores (barrels 2, 3, 10) were taken. Alvin proceeded southwest, toward the spreading axis, finding lava collapses and a ropy sheet flow, the latter sampled, before ending the dive back amid pillows where a final rock sample and sediment core (barrel 11) were taken.  

Dive:    4772
Pilot:     Phil Forte
Observers:    Stefan Sievert, Jennifer Barone
Synopsis:    We landed on the bottom and proceeded to the Vent-SID. We picked up the Vent-SID and transited to Crab Spa. We positioned the Vent-SID next to the vent and placed the wand in the vent opening. We collected 4 fluid samples from Crab Spa with the IGTs (isobaric gas-tight samplers). We then checked the positioning of the Vent-SID wand and triggered the start of Vent-SID sampling. Next we transited to the Large Volume Pump (LVP) and released it to the surface. Then we located the Mineral Colonizers and loaded them onto the basket. We collected several Riftia nearby and triggered the Niskin bottle. We briefly visited Bio9 (no samples collected) before our ascent.  

Dive:    4773
Pilot:     Bob Waters
Observers:    Katie Scott, Nuria Gonzalez
Synopsis:    Dive began at about 9 am. Minor issues with navs when we arrived at the bottom, but we found Crab Spa at around 11:35. We stowed the umbilicus of the device, moved it off of Crab Spa, and released the dive weights after a bit of manipulation with the temperature probe. We then took four IGT's in 20-25C water at crab spa. At 1 pm, we transited to Tica to retrieve the CV 85 colonizer. Once this was stowed, we collected 2-3 doz Riftia of assorted sizes. We then transited to Bio 9 to collect beehive formations. In the process of collecting these we nicked a hydraulic line and left the bottom at 2:45.  

Dive:    4774
Pilot:     Bruce Strickrott
Observers:    Scott White, Florian Gotz
Synopsis:    started south east of axis about 6 kilometers at 2790m travelled north to east to side of topographical high, moved west up the slope then north before turning west toward ridge axis. Observed multiple lavea types (pillow, lobates, sheet flow, and varied jumbled forms of lava). Heavy sediment through much of the dive although observed one are of lessened sediment before returning to area of heavier sediment. No hydro thermal activity observed.