Ice on an April morning

On a cold morning the receding tide leaves a film of ice on the seaweed and rocks along the shore.  Nova Scotia is blessed with natural shorelines like this, a haven for wildlife which is threatened by development.
On a cold morning the receding tide leaves a film of ice on the seaweed and rocks along the shore. Nova Scotia is blessed with natural shorelines like this. It's a haven for wildlife, but threatened by development. More about that in future posts. We feel fortunate to live along an undeveloped coastline.
Ice forms patterns on two species of seaweed.
Ice forms patterns on two species of seaweed.
Chunks of heavier winter ice are heading out to sea, temporarily caught in the overnight freeze, soon to be melted by the warming spring sun.
Chunks of heavier winter ice are heading out to sea, temporarily caught in the overnight freeze, soon to be melted by the warming spring sun.

The edge of the ice

The tidal inlet on January 2, 2009
The tidal inlet on January 2, 2009

Ice always builds up and stays in the inlets where it isn’t easily carried out to sea.  At low tide it just sits on the bottom, on the mud. There’s always a dynamic edge out there forming, melting, breaking off depending on the wave action, with pieces getting carried out to sea.

Freezing and thawing

The tidal inlet on the cold morning of December 9th
The tidal inlet on the cold morning of December 9th

The temperature has been bouncing around like a yo-yo – rather like the price of gas, from minus 10 degrees C to plus 10 and back again within a few days.

Unlike fresh water, which is at its most dense around 4 degrees C, salt water is most dense at its freezing point, which is typically around minus 2 C.  The more salt is in the water, the lower its freezing point.  In oceans that freeze, the water deeper down is saltier, so it stays down, and is less likely to freeze because the high salt concentration lowers its freezing point considerably.  The lighter, relatively fresher water stays on top – so it’s more likely to freeze, and when it does freeze it has little salt in it, as I found out by tasting it.

Ice that formed over rocks at high tide, then bent and cracked as the tide fell.
Ice that formed over rocks at high tide, then bent and cracked as the tide fell - December 14.