3.4. Paradise Bay

SITE DESCRIPTION

We conducted conductivity-temperature-depth (CTD) measurements at four different stations on February 22nd 2011 in Paradise Bay, between 4:49pm and 6:26pm (see figure 25 and 26 for maps of the area). The first station was characterized by still waters, and the following three were very close to active glaciers. In fact, while on site in this high-calving area, we witnessed several avalanches. Station 4 had the closest proximity to a glacier of the four stations sampled.

Figure 25: Paradise Bay Sample Site (Larger range) Figure 26: Paradise Bay Sample Site (Closer range)

TEMPERATURE

The variation in temperatures between the four stations reflects the currents and influence of glacial waters between the stations. The data reflects that there were warmer temperatures in the top 2 metres, which was likely due to solar heating (see figure 27 and 28). At station 4, between 3 metres and 12 metres of depth, we found a large cold water mass measuring 0.5°C. This is surprising as one would expect colder water to be denser than the warm water beneath it, and therefore sink below it. This phenomenon indicates that the cold water mass was much fresher than the saltier, warmer water underneath it. Once again, this was most likely due to the proximity to glaciers. Temperature ranged between 0.35°C and 1°C in the sampled area and our average temperature was found to be around 0.8°C. Stations 3 and 4 exhibited higher variability in the first 10 metres and are found at colder temperatures, which shows that the surface waters were colder than what we might normally expect from typical temperature stratification.

Figure 27: Temperature Station

Red = Station 1

Green = Station 2

Purple = Station 3

Brown = Station 4

Figure 28: Temperature Section (Stations 1 to 4 from right to left)

SALINITY

Paradise Bay exhibited interesting salinity trends. Due to the close proximity of glaciers, we detected a thin layer of fresh water at all the stations that had lower salinity than what we might have expected. This effect was most pronounced at Station 4, which measured a salinity of 33.1psu. The most saline waters in this area were calculated at approximately 33.8psu. This demonstrates that there was only a 0.7psu difference between the most saline and least saline waters in the sampled area. Overall, salinity ranged between 32.8psu and 33.8, but most stations were between 33.2psu and 33.75psu.

Figure 29: Salinity Station

Red = Station 1

Green = Station 2

Purple = Station 3

Brown = Station 4

Figure 30: Salinity Section (stations 1 through 4 from right to left)

T/S PLOT

The potential temperature/salinity (T/S) plot (see figure 31) recorded the following ranges of potential temperature:

Station 1: 0.8C and 1.5C; Station 2: 0.8C and 0.92C; Station 3: 0.6C and 0.86C; Station 4: 0.34C and 1C.

Figure 31: Potential Temperature - Salinity plot

Red = Station 1

Green = Station 2

Purple = Station 3

Brown = Station 4

DENSITY

Density ranged from just over 16.8 kg/m3 to just below 16.4 kg/m3. Paradise Bay exhibited a high degree of mixing, and as the figures 32 and 33 below show, density was driven by temperature in some areas and driven by salinity in others.

Figure 32: Density Plot of Paradise Bay

Red = Station 1

Green = Station 2

Purple = Station 3

Brown = Station 4

Figure 33: Density section plot of Paradise Bay