--- In
BoundaryPoint@yahoogroups.com, Tom Sanders
<hilversum96@y...> wrote:
> Now you've stirred my curiosity, :)
great
i love the stuff
& you see how most prefer to fluff & duff
more below
> I based my low water theory on living on Lake Huron
> and watching the high water levels fluctuate from year
> to year. Dry winters usually mean siginificantly lower
> water levels on all the Great Lakes during the next
> summer. But the ups and downs always average out in
> the short term.
>
> However, my neighbors tell me that our beach wasn't
> here when they moved here in 1969. Their boathouse,
> which is now separated by a hundred or so feet of
> beach from the shoreline, was originally right on the
> water. So the high water mark has retreated that far
> over 34 years.
>
> Place that scenario in the St. Clair flats, I
> reasoned, and it's possible that sandbars could become
> permanently exposed, and islands could increase in
> size over 30 or 40 years.
wonderful
i am with you loud & clear on all the above
> I'm also guessing that the shipping channel is the
> same one used before the Seaway by Great Lakes
> freighters, and dredged to accomodate ocean-going
> ships when the Seaway was built. Also that the border
> always follows the main shipping channel.
ok i would second guess on both of these guesses tho
as i think you also do below
i believe the border from lake of the woods to akwesasne did all
begin by following the main shipping channel or thalweg
but clearly the dry boundary on seaway island is exceptional if
not unique along this vast reach of caus in no longer following
any channel
& such a desertion of the border by the channel could only have
occurred suddenly & not gradually
like say during a huge spring flood
or if the main shipping channel was ever rerouted by design
If the
> current channel had been cut through Seaway Island in
> 1958, and the border re-aligned to follow it, we'd
> know about it, for lack of better words.
>
> It's possible that the Walpole Island seaway project
> involved cutting a new water path through Bassett
> Island (the "cutoff" on the topo map). That would have
> created a new island, appropriately named "Seaway."
yes this is exactly my guess
perhaps circa 1959
& it would explain when & why the border didnt come along for
the ride to the new cutoff
but not yet when or why seaway island grew into the usa
my guess for that is partly the lowering water levels you describe
but especially the dredging of the saint clair flats canal
date unknown but possibly circa 1959 too tho maybe much later
& which appears to have included a deliberate new riprap or
embankment plus landfill additions to seaway island behind it
including the complete backfilling of part of the original
navigation channel along the caus line
hence this so precious & probably unique little dry stitch along
an otherwise completely wet seam
> (Thanks for those Walpole Island links, BTW. That's
> always been a favorite place of mine.)
>
> You'd really need to compare the current topo with a
> pre-1958 large scale map of Lake St. Clair. None of my
> old large-scale SE MI road maps cover Harsens Island
> or the St. Clair flats. (The current AAA, American
> Auto Club, SE MI map, 1 inch to 3.5 miles but not
> exactly a definitive reference for shoreline
> alignments, does, but doesn't show the sliver of
> Seaway Island extending into the USA.)
>
> Or it might be the time for a one-day border
> expedition to the far southern tip of Harsen's Island,
> to see what can be seen.
>
> Either way, as with the knothole in the board fence
> out by the nudist camp, I'll be looking into it, :)
bravo
& we will be with you looking over it