 200 kHz acoustic volume scattering
image
of Kelvin Helmholtz waves on salt-fresh interface (Oakpoint, Long Reach, Saint John River) |
GGE 5013 - Oceanography for Hydrographic Surveyors
September 2008 John E. Hughes Clarke http://www.omg.unb.ca/GGE/GGE5013_Current.html |
GGE 5013:
John Hughes Clarke (jhc@omg.unb.ca) -
453-4568
(office - E32) - 449-0785 (cell)
Coastal and
Continental Shelf Oceanography 12 classes ....
Tides and
Water
Levels - 12 classes....
GGE 3353 (first 4 intro
oceanography
- marine geology classes and single tides classs)
Hydrographic Surveyors have always had be aware of the physical processes that control the type and variability of both the watermass and seabed. These media impact significantly on the performance of seabed survey instrumentation. Sea surface level is a variable that has to be quantified to bring depth observations to a defined datum, and surface seastate affects vessel performance and sonar-water coupling. The watermass controls the progagation refraction and attenuation of acoustic signals and the physical properties of the seabed controls the reflection and backscattering of sound.
Historically, hydrographers have focussed primarily on the sea surface changes over tidal periods or longer. With the advent of heave sensors and automated bottom detection, the higher frequency vertical motion spectrum became of interest (although there was little realisation about some of the long term drifting issues with the early heave sensors). As sound speed probes have become more common, the bar check method has become less used and a continuous sound speed profile has replaced the single harmonic mean estimate for most (but not all) single beam operations. As oblique sounding has become the norm, the sensitivity of range/angle measurements to refraction has blossomed into one of the greatest challenges to precise hydrography. As such, a vastly increased interest in the spatial variability of the temperature and salinity characteristics of the watermass has arisen.
As swath sonars, used together with modern visualisation methods, have improved, our ability to recognise fine scale systematic artefacts in the data has increased. Shiptrack parallel and orthogonal ribbing and ridging is now easily visible at vertical scales of as little as 0.25% of the water column. Clients now perceive these all-to-apparent artefacts as limitations (even though they may be within survey specification). The modern hydrographer therefore, needs to be cogniscent of the shape of natural submerged landscapes (seascapes) so that they can rapidly assess the whether such artefacts are present. Both the range and resolution capability of swath sonars are particularily sensitive to the bottom backscatter strength and thus the surveyor must be aware of the likely natural variability in this parameter. Surveyors should thus also be cogniscent of the likely variability in surficial sediments (which control the bottom backscatter strength) in an area within which they are intending to survey.
This course is designed to describe the physical processes in the
marine
environment that are of interest to the hydrographic surveyor. A
limited
field program involving the measurement of critical oceanographic
parameters
(tides, currents, temperature and salinity and surfical sediments) will
take place in the lower Saint John River Estuary to demonstrate the
practical
aspects of observing these parameters.
12 Oceanography-
Marine
Geology Sessions
12 Tide - Vertical Datum Sessions
PRACTISE
The course will be given as a series of lecture/discussion periods on :
Tuesday 0830
-1000 E-16
Thursday 0830 - 1000 E-16
And including an extrea 1 hour time slot for visting lecturers and
scheduling mismatches:
provisionally 1500 -1600 on Fridays in E16
The course will be broken into two main sections:
Coastal Oceanography
and Sedimentology - First
Half of Term
Tides and Water Levels -
Second Half of Term
| Sunday | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Comments |
| 31st August |
Intro Class |
||||||
| 7th September |
OC class 1 |
OC class 2 | LAB
1: |
||||
| 14th |
OC class 3 |
OC class 4 | Oceanography | ||||
| 21st |
OC class 5 | OC class 6 | |||||
| 28th |
OC class 7 | OC class 8 | LAB
2: |
||||
| 5th October |
OC class 9 | OC class 10 | Geology |
||||
| 12th |
THANKSGIVING | OC class 11 | OC class 12 | JHC away |
|||
| 19th |
TIDES class 1 | TIDES class 2 | |||||
| 26th |
TIDES class 3 |
TIDES class 4 |
LAB 3: | ||||
| 2nd November |
TIDES class 5 | TIDES class 6 | Tides | ||||
| 9th |
TIDES class 7 | REMEMBRANCE | TIDES class 8 | ||||
| 16th |
TIDES class 9 | << IAN |
TIDES class 10 | << IAN |
JHC AWAY |
||
| 23rd |
TIDES class 11 | << SUE |
TIDES class 12 | <<SUE |
JHC AWAY |
||
| 30th |
Spare Slot |
LAST DAY OF CLASSES | TAKE-HOME EXAM |
||||
| 7th December |
5013 students have to do 3 labs in 2008:
LAB
A 2006
- MVP Analysis in the Bay of Fundy
LAB
A 2007/8
- MVP Analysis off the Scotian Shelf
LAB
B 2007/8
- Geologic (multibeam and subbottom) Analysis off the Scotian Shelf
| 0-44 | 45-49 | 50-54 | 55-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-89 | 90-100 |
| F |
D |
C |
C+ |
B- |
B |
B+ |
A- |
A |
A+ |
| Course mark is
determined as follows: letter grades are converted
to grade points as listed below: |
|||||||||
| 0 |
1 |
2 |
2.3 |
2.7 |
3 |
3.3 |
3.7 |
4 |
4.3 |