The Fundy Biosphere Reserve

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Moncton's Frozen Frontier - Descending into the Belly of the Frozen Petitcodiac

Bore Park on the Petitcodiac River is designated as a Fundy Biosphere Reserve Amazing Place due to the tidal bore viewing opportunity.  Recently surfers showed us a new side of the river, and since I’m no big fan of mud, I decided to find another way of exploring the river; by climbing down into it at low tide when the muddy banks are frozen.

A world of “chocolate” and ice on the frozen Petitcodiac River. Photo credit: Craig Norris

Nearly everyone I tell this story to thinks I’m reckless with my life.  Don’t misunderstand me, fear is healthy when you’re snowshoeing the bottom of the Petitcodiac River channel during the middle of February with -29˚C windchill, but it can be done safely.  If you dress for the weather, cover up exposed skin (no-brainer), wear snowshoes built for grip on steep ice, and use good poles, you are outfitted correctly.  Perhaps even more important is knowing the environment.  Can you believe I’m writing about a place in the middle of a city?

Serrated metal, alpine rated snowshoes. Photo credit: Craig Norris

In the early winter, the river essentially builds an ice wall in much the same way we’d build a brick wall.  It strands ice chunks on the channel banks each tidal cycle, which freeze to the bottom and the repetition of this process builds an ice block wall higher and higher; it even fills in the gaps with a slushy mortar.  Eventually, the channel develops solid ice walls.

Steep ice wall on a Petitcodiac side channel. Photo credit: Craig Norri

Despite steep ice walls, on the insides of curves in the channel, there is typically a point bar exposure of mud at low tide that forms a low, solid ice shelf.  In these places, if you find a break in the ice wall, you can easily descend onto the ice shelf and let your exploring begin.

Exposed channel bottom frozen solid on the inside of a river curve. Photo credit: Luc Perrin

It only takes 2.5 hours for the tide to fill the river, and another 2.5 hours for the tide to drain again.  This leaves the tidal channel empty for 7.5 hours each tidal cycle.  During that time, cold temperatures (think -20 ˚C) can freeze deeply into ice walls and surfaces, making them safe.  However, as the tide is receding it can leave false ice skin surfaces with cavities below, sometimes filled with pooled water.  Unstable slush banks can also build up along the edge of the river.  If you are careful to avoid stepping in these places, your grip is good, and you’re using your head, there should be little to worry about. 

Passing by an ice skin surface with a potential unfrozen pool below. Photo credit: Craig Norris

On cold days, the river water is warmer than the air and steams continuously.  This steam creates surface hoar frost facing the up-river side of any surface.  There are many other compelling crystalline ice features to see around the tidal river on cold days.

Surface hoar frost crystals. Photo credit: Ben Phillips

With the cold, slushy, dense winter water in the river, the tidal bore is muted.  The change in the water flow direction is easily noticeable when the bore arrives, indicating it is time to leave the channel.

With the arrival of the tidal bore, getting to the top of the ice wall is helpful for continued well-being. Photo credit: Craig Norris

After spending time out of sight on the lower ice shelf, you have the feeling you are deep in the wild.  There are no other signs of people anywhere, and it is a completely natural and extreme looking landscape; you imagine you’re exploring glaciers.  Then your head raises above the bank as you climb up and you are shockingly, back in the city.

Exploring a "crevasse" with Moncton in the background. Photo credit: Craig Norris 

Winter can offer the chance to experience extraordinary landscapes.  The Amazing Places Challenge is encouraging people to get out and visit all 50 Amazing Places in the Fundy Biosphere Reserve to celebrate Canada's 150th birthday and sometimes they are better to visit frozen.

This article is the sixth of seven in the Amazing Places Challenge series. 

Financed by The Government of Canada