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.