photo credit: Travis Hamilton
|Nuliajuk 2012 Mapping Operations
James Muggah, Travis Hamilton, Steve Brucker, Weston Renoud, Anand Hiroji,
Ian Church and John Hughes Clarke
Ocean Mapping Group
Dept. Geodesy and Geomatics Engineering
University of New Brunswick
|The new equipment was installed
together with the FCV-30 on a dedicated
new steel blister on the starboard underside of the vessel. This steel
blister has proved to be ideal. No significant flow or
engine-associated noise has been noted. Compared to the same sonar,
when previously installed on the CSL Heron in the same conditions
(Baffin Island fjords in 2006/8), the maximum depth now achieved is
over 300m whereas the Heron only ever achieved 220m, suggesting
improved noise characteristics.
The installations provides high quality data at speeds up to 10 knots (warp speed) and in +/-5 degrees of roll and or pitch. The installation is permanent, and the transducers will be left on board over winter for possible 2013 operations. All topside electronics are being returned to UNB for storage, maintenance and upgrading.
Apart from a 2 day window in mid August, all the Nuliajuk mapping in Nunavut took place during a 30 day period covering the full month of October. The UNB mapping team boarded in Clyde River and disembarked in Iqaluit. The main target areas were:
Both GN and ArcticNet objectives were met here:
October 3 days - The transit in from Clyde and 2 days of mapping were utilized to build a new corridor to the NW through completely uncharted waters. The aim was to both expand the areas in which potential clam habitat might be found (20-100m depths) and build a safe coastal shipping corridor towards Kivitoo.
On the third day, the weather was bad from the NE, making the clam corridor too exposed. As a result coastline sections to the south of Broughton Island and into Kingnelling Fjord were undertaken to overlap the Siferd surveys.
ArcticNet single day was utilized searching for evidence of drowned terraces/boulder barricades within the harbour area itself. All the coverage was inside the preexisting CHS coverage.
The GN mapping is almost entirely outside the pre-existing CHS 50m line spacing single beam surveys (1995 and 2005) and thus could be used for a new edition of an ENC in the area.
|Merchants Bay Mapping Objectives
The western flank of Merchants Bay had previously been identified from diving to be a possible hot-spot for Mya Truncata (soft-shelled clams). The two localities, identifed by Siferd were mapped in a single day. Additionally Boas Fjord was suspected to contain submerged terraces for sealevel history studies for MUN.
The only pre-existing charting surveys in Merchants Bay date from 1955, undertaken by the USS Tanner (AGS-15) in support of the Padloping Island weather station (VFU8) and the Durban Island DEW line station (FOX-E). The majority of the Bay, including four major fjords is completely uncharted. Interestingly, SE of Padloping Island, depths in excess of 525 fathoms (~960m) were reported by the USS Tanner in 1955 which, if this can be verified, makes it potentially the deepest fjord in Baffin Island. Sam Ford fjord, at ~ 900m is currently the deepest known.
The focus site was Boas Fjord where a suspected terrace halfway in and one at the head of the fjord were both investigated. In addition, in order to get to the head of the fjord, a previously unknown sill was identified and partially surveyed (enough to safely get around it).
Note that the centre of the fjord is beyond EM3002 tracking depth. The FCV-30 sounder maintains tracking (up to > 1500m) and thus it is hoped that at least a crude representation of the bathymetry > 300m can be preserved.
As an anchorage site on the way out, the "Unnamed" cove was investigated and found to also contain a useful submerged terrace.
There were two main objectives on the Cumberland Peninsula:
|Exeter Sound, Totnes Roads, Mermaid Fjord
The original objective for Exeter Sound was a drowned beach in the outermost approaches. But due to weather limitations, shelter had to be sought in the inner basins. In this area, secondary geoscience targets were investigated for ArcticNet. The maps adjacent illustrate the regions investigated. These include:
This work involved 2 days of mapping in the Sound (plus an extra day trying to rebuild the anchor winch). As part of this ArcticNet mapping, 4 safe anchorage havens were established (two of which indicated submerged terraces).
Transits between the havens provides new safe navigation corridors. Some of the sections are approaching the extinction limit of the EM3002 (~300m). With just a few more days on site, these corridors could be enlarged to justify a new (first ever) ENC of the Sound.
with section into Brown Harbour
|Kikistan Island Reconnaisance|
|Kekerten Harbour Detail.|