Ice-smashing, continued

Yesterday, the Weather Network published an article about the removal of ice from the Rideau River. Here's an interesting statistic from it:

Prior to the Amphibex's introduction, as much as 8,000 kilograms of dynamite would be used, scarring the riverbed and killing some wildlife. Today, only between 700 and 1,500 kilograms is used, limiting the damage.

The task costs something like $500,000, apparently. Another fact I learned for the first time from this article was that the"annual ice-smashing exercise in Ottawa has been in effect for more than a century."

This year I see that the river men have been making a sort of rectangular grid of trenches on the melting surface to facilitate the break-up of the ice. It looks like a giant game board, with the Amphibex and its workers working from rectangle to rectangle as it slowly makes its way from one side of the river to the other. By the end of today, they'll be past our house.