Wednesday, July 16, 2008

signing off for 2008

Today's blog brought to you by:
Darlene Lim

Photo: Darlene sectioning microbialite at Pavilion Lake
Photo credit: Bill Taylor

A Summary of Phase II of our 2008 field season – great field science, and tired so-longs for now

With the departure of the Deepworkers from Pavilion Lake on July 3rd, came the arrival of a new crop of researchers to move the project into the second phase of field operations. From July 4-11th, the PLRP was engaged in science diving activities in Pavilion and Kelly lakes. These dives were primarily to support the PLRP geobiological investigations. During these dives, water, microbialite, sediment, and microbial mat samples were collected for a variety of analyses (geochemical, microscopic, mineralogical, molecular, organic, thin section and taxonomic). Some ground truthing of the Deepworker waypoints of interest was conducted, however given the long list of science items we had to check off, we decided to leave much of the ground truthing to another expedition next year. A subgroup of the geobiology team spent 3 days investigating ponds on the Cariboo plateau, which are viewed as geochemical book ends to our understanding of carbonate precipitating environments. Greg Druschel from the University of Vermont conducted micro-electrode analyses to help with our understanding of the sediment redox chemistry in these ponds and Pavilion Lake. As well, Alfonso Davila from NASA Ames used a portable Raman spectrometer to investigate organic signatures in the microbialites and the mats from the various lakes and ponds.

Bekah Shepard spent hours diving in 10-20 feet of water investigating the unusual mat morphologies in the shallow regions of Pavilion Lake. While scouring the lake for interesting slime, as she puts it, Bekah discovered depressions in the shallows that had the distinct odor of hydrogen sulfide (that horrid rotten egg smell), indicative of the presence of sulfate-reducing bacteria. This led to water samples and pH data being collected from these points of interest. Bekah and Harry Bohm also discovered a region of incoming groundwater in Pavilion Lake. PLRP members have been on the hunt for a recognizable input point for groundwater for years, however given the low, diffuse flow throughout most of the lake, this find has eluded us – until now. The spring was located in the shallows, and was visually and thermally apparent to divers. This will most certainly be a region we will return to in the future to sample the groundwater for limnological and isotopic analyses. With the discovery of this spring, we hope to better understand how to locate others in the lake, and to determine whether or not the groundwater is an important contributor to the development of microbialites in Pavilion Lake.

The UBC-GAVIA team conducted mapping work at Pavilion and Kelly lakes, and added to their growing data base of sonar and photographic images from these two sites. Their research, along with that of Geoff Mullins from Simon Fraser University, has been the backbone of our understanding of Pavilion Lake’s physical characteristics. The SONAR maps produced by Geoff provided high-resolution remote sensing data that was used to plan Deepworker dives throughout Pavilion Lake. Water samples and pH profiles were also collected from a series of other regional lakes and ponds as part of the PLRP’s long-term limnological monitoring program in the area.


Throughout all of these science activities, the PLRP had the privilege of hosting Bill Taylor, a high school physics teacher from California, who was embedded with the team for the duration of Phase II. His enthusiasm, humor, and energy were infectious, and I know that his students will benefit greatly from all that he learnt while in the field with us.
We had an incredible team that made the 2008 field season possible. All supported each other through long, hot days, and late, tired nights. It was amazing to watch in action, and such a privilege to be a part of. Thank you again to the Ts’kw’aylaxw First Nations people, Pavilion Lake Community, B.C. Parks Service, and in particular to Mickey and Linda Macri, and Ron and Lorna Cook, for the incredible support and encouragement. As well, thank you to the Canadian Space Agency CARN program, NASA ASTEP and Spaceward Bound programs, Nuytco Research, McMaster University and the National Geographic Society for funding our PLRP endeavors over the years.
This is our final report for the 2008 field season. Thank you to everyone who has been following our adventures – stay tuned for more to come in 2009.
DSSL
July 14, 2008

Wednesday, July 9, 2008

Science week/Tuesday


Circa 1970's beer can with microbialite growth recovered from Pavilion Lake


Photo:
Carol Turse

Science week continues with some of the team completing more dives at Pavilion Lake, some continuing to prepare samples for transport back to the lab and the remainder taking field trips to nearby lakes for additional observations and sampling.

• Dives completed at the Herms, top of the mounds, Willow Point, Three Poles and the South Basin. A chimney sample was taken from Willow Point. A beer can was retrieved with microbialite growth. A preliminary investigation identifies the can label as the type of can that might have been distributed in the 70's.
• Gavia completed 7.5 hours of investigation in Kelly Lake
• Additional mat samples were obtained at Pavilion Lake South Basin and Willow Point
• Samples and readings were taken from Good Enough Lake, Clinton Lake and Probe Lake.
• Tuesday night’s science meeting discussed Phoenix findings and its relevancy to the work here. Alfonso led the discussion. In an amusing side note, Bill Taylor, Alfonso’s STAR teacher assistant for the summer, shared his observation of the role of graduate students in the Pavilion Lake work. He commended them for their work in tackling the ‘stinky lakes’ by doing the messy physical work of retrieving the samples, Gavia and other ‘up close and personal’ aspects of science research.
• The dry ice arrived today – there is a good quantity. The samples will be completed, packed and shipped Thursday.

Monday, July 7, 2008

Another martian twist at the PLRP

Alfonso Davila
NASA Ames

It's about to get really nasty. Tomorrow some of us are heading to the Basque Lakes, a group of lakes characterized by a high concentration of magnesium-sulfate salts, which at this time of the year precipitate here and there and everywhere, forming small brine pools. Bacteria feed on these sulfate salts, leaving behind a collection of sulfide minerals and gases. Getting your nose too close to these pools will engrave long-lasting, stinky memories in your brain. Watch your step, or they may leave long-lasting stains on your boots and trousers too. Nothing in these black and white smelly ponds will be of interest to your eyes, unless your interests lie in finding out if life was ever present on Mars.
Magnesium sulfate salts, mainly epsomite (MgSO4-7H2O) and its dehydrated twin kieserite (MgSO4), are the most common evaporitic minerals identified on Mars so far. They have been found in the vast flat lands of Meridiani Planum and in the steep walls of Valles Marineris. These minerals are a window into a period of the history of Mars when liquid water was stable and abundant on the surface. In the Basque Lakes, magnesium sulfate salts are breakfast for many microorganisms, which in turn are lunch for others and so on down the menu. To many of you the resulting ecosystem may not be the prettiest expression of mother nature's masterpiece, but perhaps the simplicity of a mathematical equation will change your mind:

Mg-sulfate + H2O + Life on Earth = Mg-sulfate + H2O + X on Mars

Figure out X and you may find beauty. This is one of the many equations that justify Mars analogue research. It is based on the fact that there is many places on Earth that resemble Mars today or sometime in the past. Pavilion Lake may be an example. The Basque Lakes may be another. Studying these analogue environments brings us a step closer to understanding Mars, its evolution and its potential for life. It helps us guiding and designing the next robots that will be sent to Mars, and are the perfect grounds for testing the instruments that they will carry, or the life support systems that humans will use themselves one day. This year we brought a portable version of one of these instruments: a Raman Spectrometer. We use the Raman to identify special compounds within bulk samples that are of interest for one reason or another. Organic compounds are one example, sulfate salts are another. The working principle of a Raman Spectrometer is the same as bouncing a ball against something. Bounce it against a concrete wall and it will come right back at you. Bounce it against a pillow and it will come back much more slowly (or it won't come back at all!). After bouncing the ball many times against many different things, you may be able to recognize the type of material you are hitting just by seeing how fast or slow the ball is coming back to you. A Raman does not throw balls but instead it shines a laser into the sample. After interacting with the sample the laser comes back with a different wavelength (wavelength shift), the equivalent to the speed of our ball. Organic compounds and sulfate salts induce characteristic shifts on the laser, which can be easily identified on the screen of the computer attached to the Raman. This way we hope to be able to easily identify any sulfate salts and organic compounds in the lakes. I can almost smell them...

Monday - July 7

Carol Turse prepares speciman

Science week continues to go well.

• Bekah led two dives into the South South Basin. The group found signs of springs, mats, algae and other formations. The microbialites were small and large cone shaped formations and continued into the shallow water.
• Allyson dove Three Poles and brought up mat samples.
• Greg, Alfonso and Emily went to the Basque Lakes where they took samples from the 5 ponds in the area.
• Dirk hiked the fault zone and came down through the Willow Creek area observing rock formations and compositions
• Zena finished with ALL the submersible tapes. In addition she scanned all diver logs. A huge job - now complete.
• The remainder of the team prepared specimens and packed equipment for tomorrow’s visit to nearby lakes

Smooth Sailing - Day 2 Science


Allyson Brady and Darlene Lim prepare samples.
Photo by Carol Turse

Operations continue to go smoothly, we are still a day ahead of schedule!

1. Retreived samples at 35' and 85' near Three Poles for the seasonal study.
2. Sampled water chemistry from yesterdays 'TOP' mat area
3. Retrieved Licor and Thermisters from Three Poles science transect
4. Sampled core from 106' at Willow Cove with microelectrode probe
5. Conducted observation dive at Three Poles
6. Completed night dives to sample at Three Poles and Willow Point
7. Conducted additional microelectrode analysis of mats and structures with some interesting findings and results
8. Water samples taken from Kelly Lake and Pear Lake

Science Continues with Bacterial Gossip


Carol Turse, Graduate Student
School of Earth and Environmental Sciences
Washington State University

photo by Emily Taylor


One of the big mysteries in the history of life on our planet is the evolution of organisms from unicellular to multi-cellular life. This transition occurred during the Cambrian Explosion and neither the conditions nor the critical variables are clearly understood. To make matters even more interesting, transitional forms are poorly represented in the fossil record. However, we are extremely lucky to have Pavilion Lake and the microbialites found here as putative transitional forms. These microbialites support a wide variety of bacteria including Cyanobacteria such as Fischerella sp., Pseudoanabaena sp. and Synechoccus sp. These bacterial species have been shown to engage in cell-to-cell signaling (bacterial gossip), more commonly called quorum sensing. This quorum sensing could be extremely important in understanding the evolution of organisms on Earth as well as those that might exist on other planets.

Today I prepared four sets of microbialite samples from two different locations on the lake. The first three sets were from the Three Poles sample site and were collected at 36ft, 42ft and 84ft. I froze small pieces of these samples for later analysis via mass spectrometer and placed the rest in small beakers of a slightly acidic solution. This solution will dissolve the calcium structure allowing me to suspend the remaining microbes in a gelatin-type mix. The different sections of the microbial community can then be isolated from the gel and the DNA extracted for analysis. Another set of samples from Willow point was already suspended in gelatin, so I isolated all the layers in that sample for DNA analysis. In the past I have found several of the genes for quorum sensing in the microbial DNA and I hope this round of samples continues the trend!

Sunday, July 6, 2008

Voltammetric microelectrode


Greg Druschel and Ben Cowie lower the microelectrode to the microbialite field

by Greg Druschel
Department of Geology
University of Vermont

Sediment porewater redox chemistry in lakes reflects the activity of microorganisms that utilize oxygen, nitrate, manganese, iron, and sulfate, giving deeper sediment porewater a different chemical signature compared to the water column. Of particular note for our research, sediment porewater organisms include sulfate reducers that generate hydrogen sulfide as a product of their metabolism. At Pavilion Lake, the location of microbialites is highly heterogeneous and they have an interesting morphology, including vent-like structures that are often associated with flow in other systems. The ‘vent’ structures observed with the microbialites have not thus far been noted to be associated with any detectable flow, but it has been hypothesized that diffuse flow may be an important part of these structures. Allyson Brady and Greg Slater have found evidence in the microbialites themselves for sulfate reducing bacteria, further suggesting that these organisms may be somehow linked to microbialite formation and morphology. We are investigating if this diffuse flow may cause upwelling of porewaters, or mixing of groundwaters with deeper porewaters, that may contain low concentrations of hydrogen sulfide or other reduced forms of manganese or iron associated with sediment porewater microbes. Hydrogen sulfide reactions may additionally change the pH of the water and potentially cause changes in carbonate precipitation, and some microbialites have been observed to include bands of different colors often associated with iron and manganese precipitates which can also affect water chemistry and associated carbonate precipitation or dissolution. We are using voltammetric microelectrodes that can measure oxygen and hydrogen sulfide (in addition to iron, manganese, and many other sulfur forms) to investigate if any of these reduced chemical forms may be present in and around the vent structures.

Yesterday, Greg Slater and Dale Andersen carried a sampling pole with a voltammetric microelectrode down to a field of microbialites at 70 feet deep in the 3 Poles region of Pavilion Lake. The electrode was attached to a potentiostat and computer on a pontoon boat where I was constantly monitoring the computer screen for changes in redox chemistry at the tip of the microelectrode. Dale and Greg placed the sampling pole in the sediment and placed the voltammetric microelectrode (a little smaller than the size of a small pencil) inside 5 different microbialite vent structures at different levels and outside the microbialites to see if there were any changes in redox chemistry associated with diffuse flow through the microbialite structures. The redox chemistry within these 5 vents was no different than the redox chemistry outside the vents, which was fully oxygenated. Our hypothesis that the occurrence and morphology of the microbialites is affected by a link with sediment porewater chemistry was not supported by measurements at these sites, but we shall keep thinking, working, and looking to unlock the secrets of these fascinating formations!

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. 

Saturday, July 5, 2008

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

Friday, July 4, 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.

Thursday, July 3, 2008

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, July 1, 2008

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).


Saturday, June 28, 2008

Day Six/Saturday

Microbialites on log


AM dive:
Deepworker: David Williams, Darlene Lim
CapCom: Allyson Brady

Willow Point – 1 hour bottom time dive
Darlene:
• Large mounds visible from snorkeling distances
• 30 degree steep slope filled with densely populated mircobialites
• New morphology – starting at 37’ there was a field of chimneys, long, thin tubes 25cm-1m tall with wall thickness of 1-2 cm
• Lots of topography to fly through – steep climbs with sheer drops
• Some video problems. Shutting system on/off randomly every 1-10 minutes.
• Sampled from 72’ – didn’t sample at more shallow depths to protect view for divers. Will come back with a smaller footprint than sub to sample.

Dave:
• Went down 70-75' feet. Little microbialite activity.
• Moved heading and at 75’ found huge (1-2 feet) cauliflower and artichoke shaped microbialites and carbonate flour.
• No microbialites at the top of ridge – algae and chara present.
• At 75' found tree suspended diagonally between wall and bottom – covered with varying sizes of microbialites.
• No samples – but carried down Discovery Channel hand held for shots.


PM dive:
Deepworkers: Bekah Shepard, Greg Slater
CapCom: Bernard

Willow Point – deep mounds
• Linear narrow ridge protruding from the sediment at 150’. New observations
• Sampled sediment profile: very heterogeneous in cross section. Signifies lots of mixing in the upper sediment layers
• Brought up 2 samples from the deep mounds.
• Fingerlike structures are much finer then those seen at shallower depths.

Day Five/Friday


Underwater Video Camera
AM dive
Deepworkers: Allyson, Bernard
CapCom: Greg

Western shoreline, along road
Bernard – south at 40m and return at 23m
Allyson – south at 30m and return at 15m

Allyson retrieved sample from 15m depth. Rock with structured microbial colony formations.

• 40m contour – sparse dome-shaped formations, with CaCO3 flour substrate
• 30m contour – large, dense structures forming down-slope reefs, separated by debris slopes
• 23m contour – large domes descending down-slope, transitioning from cauliflower- to artichoke-type at 23m depth
• 15m contour – rock slide areas. Formations on rocks mirroring slide shapes and fields of microbialite. Small cauliflower type, friable microbialites.

PM Dive
Deepworker pilots: Mike Gernhardt, Darlene Lim
CapCom: Bekah

Bernard's Day 4 Log

Bernard Laval’s CAPCOM comments
June 26, 2008

Planning: After four days, logistics are now smooth. The barge was on site for the first dive about 10 minutes before the pilots were ready. Pilots now have sufficient time to plan dives, review dive plans, pre-dive debrief, post-dive debrief, then have an overview pilots planning meeting to plan out subsequent days. Having pilots plan their own dives is proving beneficial. This allows pilots to “take ownership” of their dive plans and directly incorporate science goals into plans, while taking into account recent exploration experience. For example, regions of low acoustic return, as shown in Multi-Angle, Swath-Bathymetry (MASB) SONAR surveys, are generally found to be soft sediment bottom and are now a low priority for survey. As a result, contour-following flight plans are being modified slightly by pilots to follow regions of high MASB SONAR return. This dive plan flexibility to use remote sensing data (MASB) and diver experience helps maximize observation for a given effort.

Morning dive: Today marked a change from surveying broad regions to exploring specific targets identified a priori from MASB SONAR surveys. Mike Gernhardt and Darlene Lim explored Macri Ridge at the centre of Pavilion Lake. While earlier Deepworker dives returned samples of opportunity, today’s morning dive was planned for sample return from the deepest regions of Pavilion Lake. Today’s Deepworker exploration of Macri Ridge is much more extensive and returned much higher resolution images than the ROV survey of 2005.

Afternoon dive: Some of the most impressive microbialite specimens observed by SCUBA divers are in the vicinity of Willow Point on the Western shore of the Central Basin of Pavilion Lake. For this reason, one of the primary scientific transects was established here, and as a result this region has been well studied. This afternoon’s Deepworker dive (Greg Slater and Bekah Shepard) extended these observations by surveying contours (15, 23, 30, and 40m) along the entire Western shore of the central basin. Pilot observations established that MASB SONAR returns in this entire region are indeed extensive coverage of massive microbialite reefs.

Tomorrow: Tomorrow’s planned dives will explore the Eastern shore of the Central Basin. The original scientific observations at Pavilion Lake were made at the current location of this shore near the current Three Poles scientific transect. The Deepworker will extend SCUBA observations and ground-truth MASB SONAR data.

Friday, June 27, 2008

Day 4 Diver's log

AM dive:
Deepworkers: Mike Gernhardt, Darlene Lim
CapCom: Allyson Brady

• Explored deepest regions of lake near Macri Ridge at the centre of Pavilion Lake.
• Successfully

PM dive:
Deepworkers: Greg Slater, Bekah Shephard
CapCom: Bernard Laval

• Explored Willow Point/western shore of Central Basin where massive microbialite specimens previously indicated by sonar were observed. took sample from deep trench microbilate growth

DeepWorker Report - Greg Slater:
This afternoon Bekah and I followed up Darlene and Mike’s exploration of the deep mounds at the center of the lake. We were all really excited by the reports brought back my Darlene and Mike about the unusual morphologies, colours and distributions of the microbialites at these deep locations. And we were all particularly excited to see our first sample retrieved from this location by Darlene. Sampling of these deep mounds is one of our primary goals for this research.

This successful dive set expectations high for Bekah and myself. And for me, these expectations were fulfilled. This was the first dive I have had that went according to the dive plan. I covered the 30 m and 15 m contours along the western wall of the central basin. My deeper contour that was flown between 90 and 100 feet, ran along the bottom of the primary microbialite structures. This confirmed that the hard returns on sonar were microbialites and that they ended at this depth. On the way back, I flew over what appeared to be the upper contact of the structures. There was an almost continuous ridge of structure all the way down the side of the lake. It was amazing to see the extent of this ridge along the side of the lake. Both the structures at depth and this ridge were very similar to what is observed at our science transect at Willow Point. This was great to see as it demonstrated that this science transect is representative of this entire shore of the lake. So, rather than coming from a unique site, our research here is really representative of the entire shore. The ability to cover such a large distance ( 2 km of contour) with the Deepworker was invaluable in confirming this. Not only was the science exciting, but at several points Bekah and I came close enough together to film each other working. I can’t wait to see the video of this.

Below the surface...

video

First clips of sub video exploring south basin microbilites at Pavilion Lake.

Thursday, June 26, 2008

Day Three Debrief


It is the end of day three and we are really starting to hit our stride with the science goals that we have set for the deepworker component of the project. Our launches are more efficient and with our increasing ability to have effective debriefing meetings, we are learning a lot from our collective experiences. We are also increasingly getting a handle on mission planning and are benefiting hugely by the direct planning of missions by the science/pilot team. We can use our experiences in our initial dives to determine what future dives hold priority and how to manage scheduling and optimize resources. We are continuing to develop as a team with common goals of advancing our scientific program as well as developing approaches to operational planning and metrics.

In terms of our science goals, we are making excellent progress in addressing our original hypotheses as well as formulating new ones and new directions for this deployment. This is really highlighting the strength of advanced, informed planning, as well as the equal importance of the ability to adjust planning during the project to adapt to new information and insights.

One of our primary research goals is to investigate the role of groundwater in the Pavilion Lake system and its potential contributions to the microbialite formation. This is being addressed by deepworker dives focused on exploring the correlation of microbialites with different geological settings. Much of the north basin, where we began our dive program, is underlain by granite. Such a granite basement would be expected to have relatively little groundwater flow and as such, our hypothesis is that there would be fewer microbialite structures associated with this environment. And our results so far are supporting this hypothesis as very little microbialite structure was observed. The only exception was the region where our research transect was located, which is in fact associated with the only section of argillite/scree slope shoreline where groundwater might be expected.

In our more recent dives in the south basin, microbialite structures have been plentiful. And we are continuing to assess the association of these structures with the potential of groundwater inputs. We have also recently hypothesized that whitish clouds observed during some dives may be associated with groundwater inputs. This new observation and hypothesis is planned to be tested in the coming days using a CTD that will be attached to one of the Deepworkers.

Overall, our progress is excellent and our initial data is really exciting. We are all enthusiastic to continue this exploration and to utilize the unique insights available through the deepworkers to address our scientific questions about this incredibly interesting site. Greg Slater, McMaster

Wednesday, June 25, 2008

2 good flights - Wednesday


Things are clicking today -

AM: 4th flight/South Basin
Deepworkers: Bekah Shepard, Greg Slater
CapCom: Mike Gernhardt

• Map 23-30 meter depths in south, south basin
• Bekah successfully retrieves first rock and microbialite samples
• Microbialites preferentially growing on rock debris flows
• Cool new carbonate spheres observed in microbial mats of the south basin
• Greg’s navigation malfunctions shortly after first way point. This delay puts him out of GPS range of nav boat. He continues the dive on com’s from barge explored microbilate structures on west shore documented depth of termination and several morphological zones. This ‘salvaged’ flight still provided useful information toward science goals. Not withstanding technical and logistical difficulties.


PM: 5th flight/
Deepworkers: Allyson, Bernard
Capcom: Darlene Lim

• North portion of South basin
• 40m contour/120 feet the bottom was carbonate flour.
• Observe 'cloud', not like deepworker sediment trail, looked lighter.
• Took video footage, GPS and attempted fly around the edges. May warrant further investigation.
• Crossed basin over to roadside shoreline and saw evidence of human debris and trash
• Retrieved microbialite growing on large rock at 80feet
• Brought home on low battery

Tuesday, June 24, 2008

Long, good day, little rest - Tuesday


AM: 2nd flight/North Basin
Deepworkers: Bernard Laval, Allyson Brady
CapCom: Greg Slater

North Basin contour mapping completed
Not a lot of formations in this area – why?

PM: 3rd flight/South Basin
Deepworkers: Darlene Lim, Mike Gernhardt
CapCom: Bekah Shepard

Gernhardt’s communication link with the navigation boat malfunction – despite this he is able to explore using a magnetic compass and dead reckoning and video document several microbialite rich areas in the southern basin. Lim goes to map deeper and run by wall

Undulating bottom and steep walls make for ‘advanced flying’, subs maneuver well in more complex terrain

Rock fields observed at south, south basin

Dwarf fields of microbialites observed

Microbialites growing on canyon walls, angled upwards

Monday, June 23, 2008

First flight - Monday




AM: Subs tuned and charged for flight













PM: 1st flight /North Basin

Deepworkers: Bekah Shepard, Greg Slater
CapCom: Darlene Lim

Acoustic GPA system working well
Deepworkers able to follow contours and navigate
Observe various types of microbialites at various depths
At about 90 feet formations seem to ‘peter out’ – why?
Deepworkers map North Basin per flight plan
Lots of mud, but that fills in the map and tells us where microbialites are not.

Sunday, June 22, 2008

Barge Deployed Sunday


Barge constructed and Deep worker subs deployed. They are successfully transported, constructed and lowered into the lake.