Saturday/Science Week: Day One

Microelectrode probes microbialite chimney

Saturday
Science Week: Day One

The day went well and 7 dives were completed including checkout dives and all scheduled science dives. Two dives originally scheduled for Sunday were moved onto the Saturday list of dives – we are ahead of schedule.

 

The camp is full of new personnel who have set up the lab and additional equipment for processing samples. Except for one microelectrode cable, all equipment arrived safely. The missing cable will be here Tuesday and this backup piece of equipment is not negatively impacting current operations.

 

• All barge moorings were recovered and stowed.

• Bekah Shepard made two dives at 20’ to collect microbial mats – and identified a TOP (Target of Opportunity) about 10 meters offshore of the Willow Point transect. She notices adistinct sulfide smell and can feel warm spots as she moves through the water. She took samples and will return for further investigations

• Greg Druschel of the University of Vermont has arrived with the microelectrode. The equipment was deployed on the boat and taken to the Three Poles transect where it was deployed to targets at approximately 70 feet. Additional lab readings were completed on microbialite and mat samples.

• Bernard Laval and Darlene Lim took water chemistry samples from Pavilion and nearby Crown and Turquoise Lakes.

• Allyson Brady recovered two LIDs (Light Inhibiting Devices) that have been covering microbialites for one month and two week periods. This experiment is designed to stop photosynthesis and assess the resulting shift in the microbial communities living on the surface of the microbialites. 

Wednesday: Deepworkers Head Home

Deepworkers Head Home Today's blog brought to you by: DARLENE LIM Geobiolobist, Limnologist

Today the Deepworker submersible operations have come to an end. We have had 10 successful days of using these subs to map and sample the deepest regions of Pavilion Lake. We found that the Deepworkers were the ideal tool to facilitate deep and long range scientific mapping – they are maneuverable, efficient and safe. Deepworkers gave us an ease of movement and removed the need to decompress or to watch one’s bottom time as you would if we were SCUBA diving. This afforded the scientists the ability to fully immerse themselves in their environment during the submersible dives that lasted 3 hours and covered depths of up to 200 feet. The scientist and astronaut pilots were able to quickly synthesize their impressions of the lake and to focus on gathering thoughtful observations rather than worrying about technical issues related to such lengthy and deep dives.

As the Deepworker activities rolled along, each pilot also saw an exponential increase in their piloting capabilities. During training we were told that it is easy to pilot a Deepworker, and what is harder to do is to know how to pilot the subs well. By the second dive or so each pilot was remarking on the significant increase in their handling capabilities, which allowed them to better focus on the environment around them. This outcome alone validated the use of Deepworkers to achieve our science goals.

The flight planning and science and operational success metrics that we designed in coordination with Dr. Michael Gernhardt from the NASA JSC Astronaut office were highly successful and useful. This demonstrated the incredible utility of having scientists and astronauts explore scientifically relevant analog environments as a tool for preparing for the human exploration of the Moon and Mars. Furthermore, it was extremely exciting for each of the pilots to be able to sit in the Deepworkers and look at the lake in a holistic manner. Each evening we had All-Hands science meetings where the pilots shared their observations with the science, operations and technical team. During these meetings it was very apparent that we had made significant inroads to better understanding the variability and distribution of microbialites in Pavilion Lake as a result of having our previous exploration challenges mitigated by the use of Deepworker submersibles. These meetings were an important and highly productive part of our day as they allowed us time to engage in stimulating scientific banter and to update our dive plans based on the science priorities we identified. As well, the meetings ensured that the data was disseminated to the entire team so that as best as possible, the Deepworker experience was not limited to the six lucky pilots. This deepened the vested interest that each PLRP member had in the Deepworker activities as our science priorities were based on group consensus, which ultimately led to dive plans for the following day.

With the departure of the Deepworker submersibles today, I am relieved and melancholy. Relieved because we have had a safe and productive 10 days, and we met all of our science and exploration objectives. Melancholy because for now our time in the subs has drawn to a close. On this final point, I can write without hesitation that I will miss piloting the subs, but most of all I will miss the intellectual and emotional camaraderie that this endeavor catalyzed in the group. Over 10 short or long days (depending on who you talk to) we created a family made up of folks from all walks of life. Astronauts, scientists, engineers, technicians, boat captains, safety officers and one incredible cook. All were passionate about what we have learnt through our Deepworker deployment, and all are looking forward to continuing, growing and evolving this program into the future. As I mentioned in one of my earlier writings, it does take a community and we have created one that I know will move onwards and upwards for years to come. It is such a privilege for me to be a part of this voyage. Thank you to all of the lovely humans who comprise the PLRP community.


DSSL
July 3, 2008

Transition day

The barge and subs were disassembled, loaded and trucked back to Vancouver yesterday.

Today is 'a day off'. Everyone is resting - and planning for the science dives that start tomorrow morning.

Wednesday - Last Dive Day

Weather held and both dives completed!

Donnie’s underwater camera – RIP, the housing broke and the camera was flooded…

AM Dive
Deepworker pilots: Bekah, Mike Gernhardt
CapCom: Greg Slater

Recovered samples to better understand variability of deep water microbialites

• Recovered sample from middle of deep mound wall. Ability to hover and grasp precisely improves sample results
• Less thinking about enginnering issues and more thinking about scientific observations frees scientists to do more observation
• Very low impact on lake environment


PM Dive
Deepworker pilots: Bernard, Darlene
CapCom: Allyson

Completed mapping of N South Basin
• Fast learning curve for flying deepworker. Ability to target and grasp samples increases
• Combining horizontal and vertical thrusters increases potential. Now easily able to swing the vehicle around in the attitude you want

Tuesday dives

AM dive
Deepworkers: Darlene Lim, Mike Gernhardt
CapCom: Bernard

South, south basin the 15m and 30m contours

• Roadside structures are smaller
• Large structures on steep overhangs
• Diversified, large 12-15’ structures on west side
• Tight formation flying with Darlene demonstrated the controllability and precision flying of the Deepworker
• Topography seems to play a large role
o Layers of sediment – no microbialites
o Steep ridges – abundant microbialites

PM dive
Deepworkers: Allyson, Greg
CapCom: Bekah
Dive shortened by weather – thunderstorm
Subs returned efficiently and safely

• Piles of crushed, disposed cans at 50’ had small amount of growth
• N South basin had two more logs with growth
• At 75’ large structures with chimneys
• Evidence of rock slides
• Some very large rocks exhibited growth
• Appears that structures tapered out about 90’

Sunday dives

Submersible with diver and UBC Gavia, the autonomous underwater vehicle

AM dive
Deepworkers: Allyson Brady and Bernard Laval
CapCom: Greg Slater

Willow Point – deep mounds (1st trip for these pilots)

• Less visibility
• Mud, sediment w/no structures until first wav point
• Observed ‘fire coral’ previously observed by Mike
• Tall, drendritic formations, black colored, some damaged
• Brought back sample for this area
• Mound – objects on top, fewer large structures
• Unexplored area closer to shore contained smaller mounds

PM dive
Deepworkers: Mike and Darlene
CapCom: Bekah

Willow Point – through shoal area

• Located Dave’s tree again
• Saw algae that warrants further investigation
• Interesting transitions between dome and high apex conical structures
• Mike found a beer bottle with 1997 date – with growth
• Flew tight formation and took sub pictures of each other – flying continues to improve
• Green slime in chara intertwined with green slime and microbialites at 45-60’ depths
• Great flight – executed complex multi-legged flight plan over complex topography

Robots into the Abyss II

Brought to you by Alexander Forrest, Environmental Engineer

One of the challenges for the team working with UBC-Gavia, the autonomous underwater vehicle (AUV), is designing missions that play to the strengths of the vehicle. Additionally, the team is optimizing the collected data in order that be used directly by the Deepworker team for flight plan development. A unique application of this is the exploration of the abyssal plain of the central basin of Pavilion Lake. This part of the lake is the deepest part of the lake (~ 55 - 60 m deep) that is generally characterized by a very flat, muddy bottom and low microbialite coverage. Due to the fact that there are few targets of interest in this region, Deepworker pilots find this a tedious area to explore and so prefer to autonomous robots to explore the deep.

The main instrument onboard UBC-Gavia was the sidescan sonar. This device operates on either high or low frequency to render a relief image on either side of the AUV. A common analogy used is that it is like shining a flashlight away from the vehicle and anything that is obstructs the light is bright on one side and casts a shadow on the other. The missions that were run yesterday were being run at high frequency (better quality images) and the reduced range of 30 m (compared to 100 m at low frequency). Making sure there was sufficient overlap between each of the AUV missions, runs were conducted that covered the north half of the central basin.

It was discovered that there was very little of interest in this section of the lake (as was previously expected) but several interesting areas were identified on one edge of the runs. Odd ridging appeared in the images running perpendicular to shore that is currently unexplained (shown in the picture). This has been now identified as a potential mission priority for the Deepworkers if there is sufficient time available. Further exploration of the abyssal plain continues today in those regions that weren't previously surveyed with the boat sonar.
Sample of sidescan sonar data with the centerline representing the path of the AUV, the wavy, vertical line representing the bottom surface with the range away from the vehicle shown on the bottom axis and the obvious ridging shown in the upper right hand corner (~ 20 m off the port side of the AUV).