Thursday, September 27, 2012
Much of Thunder Bay's waterfront is industrial or otherwise difficult to access. Marina Park in the north part of downtown was nice, but all riprap. Chippewa Park south of town has two beaches. The main swimming beach (I guess some people swim in Lake Superior) is a sandy curve along a small cove sheltered by a rock breakwater.
The pictures here are of Sandy Beach, which is more exposed than Chippewa's swimming beach and lies just to the south. It's the only sand along this stretch, which made me wonder if it could have been trucked in. The beach is broken into several small curves by rock groins.
This is a uneven stretch of coastline. The adjacent shores are ragged (see aerial below), suggesting that the geology may be irregular (maybe piles of glacial cobble in otherwise soft material, or resistant ledges in softer bedrock). Or perhaps, the shoreline has simply eroded for decades and those little points are old rock groins, sort of like the ones on this beach, but without the sand in between. I have no idea and only noticed the pattern once I was back in Seattle.
This beach must be icebound all winter - so wave action is probably most significant in fall before it freezes over. I don't have enough experience in these settings to know what peculiar things moving ice does to beach gravel, although I assume under certain conditions it can leave some pretty cool landforms - ice thrusts, rafted pebbles, ice scour.
Thunder Bay at hshipman. As usual, my other blog parallels this one, but instead of rambling commentary about beaches, you get rambling commentary about other stuff. Sometimes it includes a little non-beach geology; sometimes it just has pictures of food.