OMG Bute Inlet 2014

CSL Heron - Bute Inlet Operations
June 2014
Ocean Mapping Group, UNB

Overview:

For the period June 8th (JD161) through June 12th (JD165) the Heron operated from the Bute Inlet Lodge on Bear Bay. On the previous day (JD160) transit data was collected up the fjord to the lodge on the following day (JD166) data were collected while transiting out.

The Homathko prodelta was surveyed 6 times. The Southgate, 5 times. The Homathko river mouth was surveyed just once.
Sections of the main channel were resurveyed on most days. Different multibeam sector widths, pulse lengths and offsets were used to try and optimize the imaging quality.

The distal lobe area off the Orford river mouth was covered on the transits in and out and on JD162.

Tidal Reduction, Vertical Referencing:

Predicted Tides - Waddington Harbour

In the absence of a permanent tide gauge, the predicted tides derived from constituents at Waddington Harbour were used for all real time vertical referencing.

RTG Elevations - Heron Antenna

As well as the PPP tide buoy, the real time Gypsy (RTG) solutions from the CNav 2050 (GPS SV's only), was logged on board the Heron throughout the day.

direct comparison - 5 days on location.

As can be seen, the tidal motion is reasonably predicted, just from the RTG real time solutions.

Daily Comparisons:

The following plots show the 12 hour window from 0700 to 1900 local. The RTG height solution, reduced using EGM08 to the Geoid and then arbitrarily offset to chart datum from the antenna is shown on the left. It is compared directly to the predicted tides. The centre plot shows the EGM08 modeled separation. The right plot shows the navigation for the corresponding period.

steaming in from Powell River	climbing up ellipsoid	transit in.
		recce - deployed anchors. Surveyed Homathko prodelta
		deployed ADCP Surveyed Southgate prodelta Surveyed Homathko prodelta up the Homathko near HW.
morning spent running down fjord to Orford Fan.	corresponding dip in ellipsoid	pickup ADCP, download and redeploy. Surveyed Homathko prodelta
		pickup mooring just to download hydrophone. Surveyed Homathko prodelta Surveyed Southgate prodelta
		didn't recover ADCP as too much sea. Surveyed Homathko prodelta Surveyed Southgate prodelta
	afternoon only as Generator was down in the am. lunchtime dogleg trying to meet the float plane.	recovered ADCP Surveyed Homathko prodelta Surveyed Southgate prodelta
steaming out back to Powell River	and back down the ellipsoid	slow transit out with restricted sector along channel.

Archived Oceanography:

Precise definition of the deeper depths of the fjord require a knowledge of the deep seasonal circulation. With depths of up to 650m, this is very time consuming (and the Heron only has 350m of cable). Thus the World Ocean Database, populated in this area from DFO data over the past several decades, is a useful source of that oceanography.

Archived examples from the Summer Months (May, June, July)

Summer Sound Speed	Summer Salinity	Summer Temperature

Monthly Variability.

May	June	July

Observed Oceanography:

AML deep dips

MVP deep(ish) dips

MVP Sections:
JD160

Sound Speed	Temperature	Salinity

page generated by JEHC, on board, June 7th to 15th 2014