Posts Tagged ‘tides’

Cold water, big tides

January 12, 2017

After a very cold night, there was a layer of ice on Pedder Bay again this morning which allowed for some interesting observations and data collection by marine scientists.


Data below were collected by second year Marine Science students at two different times of the morning.

8:05 am 11:00 am
Depth (m) Temp (oC) Salinity (ppt) Temp (oC) Salinity (ppt)
0 3.7 28.4 4.6 25.9
0.5 5.8 29.3 5.8 30.1
1.0 6.4 30.3 6.7 30.6
2.0 6.7 30.6 6.7 30.7
3.0 6.7 30.7 6.8 30.8
4.0 6.8 30.7 6.9 30.8
5.0 6.8 30.7 6.9 30.8

One major conclusion can be drawn:

The water is COLD (right down to 5 m where we usually measure temperatures around 10oC). It is so cold that students’ tongues are turning blue:


Wait a minute… the cold is not the reason for the blue tongues in these Biology students!

We are also experiencing big tides these days (2.8 m tidal range). High tides in the early afternoon:

Then low tides at night:


Emilio, Heather & Millie at low tide (20:15 11 Jan 2017)

Interesting times!

A very high tide

December 8, 2015

Flat rampIt is rare that the tide is so high that the lower ramp is horizontal, but today it was… And the upper ramp was inclined upward to the floating building.High tideAnd the pilings were still securing the building and dock, but they were relatively quite short…


…just slightly more than one Budnik!


Below is a photo from a king tide last year:


A low tide for comparison

February 17, 2015

As promised, here are some photos of a low tide (0.6 m on Sunday 15 February 2015) for comparison to the very high tide on 10 December 2014.





P1040331 P1040332

Tide guage    P1040337

A very high tide

December 10, 2014

Michal2With all the rain, the low atmospheric pressure and the spring tides we are seeing evidence of very high high tides – a king tide. Michal was able to touch the top of the piling.

On that piling is a tide gauge that was set up by a four students for their Group 4 project. Although it is not ‘calibrated’, I suspect they did not see such a high during their sampling.

Tide guage


Check out the height of the water under the ramp to the lower floor of the floating building:


And the angle of the ramp to the upper floor:

RampFor comparison, I’ll post additional photos of extremely low tides when they occur.

Human tide models

March 14, 2012

A recent challenge to first year marine scientists was to create a model to represent the equilibrium tidal theory using every body in their class.  This cohort of students came up with some very creative ideas and I look forward to seeing the final product resulting from their efforts.

The attractive ‘moon’ (Ben & Sergio) and the ‘water’ from A block.

The equally attractive ‘sun’ of A block (Mohamed & Suizhi).

And Jon, the videographer.

B block practicing on dry land.

In the pool!   Gabbie, the videographer, in the centre.

Sun (yellow kayak / Vuochly), water, Earth and Moon (white kayak / Sammy)

Tide challenge 2012

March 6, 2012

On 17 February, first year marine scientists were challenged to: “Design a method to measure the change in tidal height at the PC docks over 48 hours.”  They were required to have at least 20 data points within the 48 hour period.  Students came up with various methods, some of which are described below.

Thea & Amanda measured the change in the distance to the water level from the bridge going to the lower level of the floating building.

Ben & Mariana used a similar technique from the bridge going to the upper level of the floating building.

Angela & Felicia measured the change in the height of the ramp going to the docks.


Karam & Helen had a variety of clever ideas…


Mohamed & Chris did eventually manage to untangle the measuring tape above then nailed it to a piling and recorded the change in water level relative to the tape.

Many creative methods resulted in data that were then graphed and compared to the prediction of tide heights for Pedder Bay over 48 hours from 17 to 19 February 2012.  (from