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.