A Landing a Day

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Posts Tagged ‘Grenville SD’

Grenville, South Dakota

Posted by graywacke on January 13, 2014

First timer?  In this formerly once-a-day blog (and now more-or-less a twice a week blog), I have my computer select a random latitude and longitude that puts me somewhere in the continental United States (the lower 48).  I call this “landing.”  I keep track of the watersheds I land in, as well as the town I land near.  I do some internet research to hopefully find something of interest about my landing location.  To find out more about A Landing A Day (like who “Dan” is and what the various numbers and abbreviations mean in the first paragraph), please see “About Landing,” (and “Abbreviations” and “Cryptic Numbers”) above.

 Landing number 2076; A Landing A Day blog post number 503.

Dan –  I’m not happy about going 1/5 (but as long as my Score stays below 150, I’m OK), thanks to this OSer . . . SD; 57/52; 5/10; 149.2.

Here’s my regional landing map:

 landing 1

My local landing map shows that I landed next to Pickerel Lake, and not too far from the teeny weeny town of Grenville (pop 54):

 landing 2

Also not far away is the mysteriously-named “Enemy Swim Lake” (more about that later).

 My Google Earth (GE) shot shows my proximity to Pickerel Lake:

 GE 1

Stepping back a little, you’ll get to see the entire lake:

 GE 2

Before talking about my watershed, here’s a regional landing map, water only:

 landing 3

You can see that I landed amongst a multitude of lakes of varying sizes (with no streams or rivers anywhere in sight).  A little research determines that I landed in a portion of the “Prairie Pothole Region.”  Here’s a map from Wiki showing that the northeast corner of SD is just a small part of the entire region:

 PrairiePotholeRegionMap

The PPR (I feel quite scholarly saying “PPR”) is a glacially-derived terrain that has resulted in a landscape dominated by innumerable depressions, ranging in size from a fraction of an acre to many hundreds of acres.  These depressions were formed by basically two mechanisms:

 1.  The advancing then retreating glaciers left an inherently irregular surface behind, often resulting in an undulating topography with multiple closed drainage areas (i.e., potholes).

2.  In conjunction with the above, chunks of ice were often left behind by retreating glaciers.  These chunks of ice were then covered by soils and sediments deposited by the glaciers.  When the chunks melted, a particular type of pothole resulted, known as a kettle.  If the kettle is large enough to support a lake, the lake is known as a kettle lake.

 This is a very young landscape, as the glaciers retreated a measly 10,000 years ago.  It just so happens that it’s also a semi-arid region, with precipitation averaging just 20” per year (more or less) – much less than the 45” for me here in New Jersey.  The result is that typical drainage patterns of small streams leading to small rivers leading to larger rivers just doesn’t exist.  There are very few streams; rainfall runoff and snowmelt simply flow into the nearest pothole.  If the pothole is dry, some of the water soaks in to the ground and some of the water evaporates.

 Larger kettle lakes may have very small streams flowing in, but typically don’t have a stream flowing out.

 Getting back to what I really care about (my landing), I’ll show my close-in GE shot once again:

 GE 1

See that teardrop-shaped area just south of my landing?  That’s a dry pothole.  (The larger dark splotch north of my landing is a wet pothole, aka a pond).  Anyway, when it rains, water that falls on my landing ends up in that little teardrop-shaped dry pothole.  I assume that if a major rainfall occurs (or if there’s a lot of melting snow), that little pothole might overflow and the runoff might make it all the way to Pickerel Lake. 

 Pickerel Lake is a kettle lake with no outlet; so there’s no more drainage to speak of . . .

 A while back I mentioned Enemy Swim Lake.  From USGenNet.org:

 Indian name—”Tak-ain-wey-api”(Enemy Swim). There are several versions of its name origin; this one came from Abe Crawford, Felix Rondell and John One Row:  In 1812, a band of Sisseton Sioux were camped on the south bank of the lake.  A band of warring Cheyennes came from the north, and were looking for a scrap with their enemies the Sioux. They ran into the camp of the latter, a battle took place, and the Sioux got the best of them. To save themselves the Cheyennes took the water, and swam across the lake.

Before moving on, I guess I have to say something about the titular town of this post, Grenville.  After some digging, I found Volume 9 of “South Dakota Historical Collections.”  Here is an excerpt of a debate among some SD politicos (that I believe occurred in 1864) about how to deal with the Indians, so when “the President” is mentioned, it’s Lincoln.  It’s worth the read . . .

 debate1

debate2

debate3

debate4

debate5

The guy talking (a Senator Sherman) was a realist.  He realized that the treaties were worthless, and if we want to help the Indians, we need to do it with legislated aid, not more treaties that would inevitably be broken  . . .

Moving right along.  While looking at a wider map view, this is what I saw:

 landing 4

Hmmm, thought I.  This is familiar territory.  In fact, it made me hearken back to one of my favorite posts, Doran MN (posted on June 10, 2009).  This post featured some very unique hydrology going on in the vicinity of Browns Valley.  

So, for the second post in a row, I’m going to borrow some material from an older post:

 Here’s a map, showing “Lake Traverse” which is a headwaters lake for the Red River (a tributary of which flows north out of Lake Traverse).   The Red River continues north, eventually discharging into the Nelson River and then Hudson Bay.  

A little bit downstream, the Little Minnesota flows into big Stone Lake.   From there, the Little Minnesota flows to the Minnesota which flows to the Mississippi.

 browns-valley

So right there near the town of Browns Valley is a significant watershed divide, with water either going to the Hudson Bay or to the Gulf of Mexico!!

 What’s fascinating is that the land between the Little Minnesota and Lake Traverse is pretty much flat.  Check out this picture that shows the flood of March 2007.  We’re looking south from Lake Traverse in the foreground towards Big Stone Lake. The flooding you see (south of Lake Traverse) is from the Little Minnesota.

 zz-browns_valley_flood_07 

Look carefully, and you’ll see that water’s coming into Lake Traverse from some kind of opening under the highway (a little way in from the lower right corner of the photo).  Think about it!!  At that moment, the continental divide is actually within a body of water!! So, two adjacent water molecules might be flowing down the flooded Little Minnesota. They just happen to flow toward the passageway into Lake Traverse.   As fate would have it, one molecule hangs a left ends up in Hudson Bay; while the other stays straight and ends up in the Gulf of Mexico. Very cool. Very cool, indeed . . .

 Moving right along:  I’ve read that the Red River of the North has a relatively flat gradient, which makes the river sluggish, and more susceptible to flooding.  I also read that the gradient is getting progressively even flatter, because of isostatic rebound.

Isostatic rebound is the phenomenon whereby the land surface actually raises when the load of glacial ice is removed. Even though the glacial ice left 10,000 years ago, isostatic rebound is continuing today.  Because the glaciers were thicker and lasted longer further north, the land further north is rebounding more. Therefore, the river gradient is getting progressively flatter.

 Imagine if isostatic rebound were to continue indefinitely. It could be imagined that the Red River (or at least parts of it) could begin to flow south, joining up with the Little Minnesota. My oh my, what hydrological havoc!!!

 Disclaimer: I strongly suspect that hydrologists have looked at this and have concluded that it won’t happen. I just found it fun to think about . . .

 Prompted by my own disclaimer, I did the following Google search:  Browns Valley isostatic rebound.  Bingo!  I found an article (from MinnPost.com) that goes to lengths to explain why flooding is such a persistent problem for the Red River.  The article is entitled “Too often a losing battle: Geological forces are stacked against the Red River Valley.”  

Here’s the excerpt from the article that talks about isostatic rebound:

 And there is yet one more geological problem that is playing out in the background of the flooding: Canada is literally rising.

 “The weight of the glaciers depressed the surface of the Earth and since the glaciers receded, the land to the north has been rising,” Thorliefson [Harvey Thorliefson, head of the Minnesota Geologic Survey] said. The ice sheet that covered Canada was more than 2 miles thick. When it melted starting about 12,000 years ago, the land that had been under the ice quickly rose, or “rebounded,” almost 1,000 feet. In the intervening 10,000 years or so, it has risen another 1,000 feet and, according to Thorliefson, still has another 650 to 1,000 feet to go.

 Why that matters is that the Red River flows downhill into Canada, and the bottom of the hill is rising. The river has already lost 50 percent of its gradient, Thorliefson said, and will lose more over the next few thousand years. It won’t be enough to make the river reverse direction and flow south, but it will slow the already-slow river even more, thus increasing the danger from floods. “It will become gradually more sluggish,” he said.

 Phew! I’m hydrologically and geologically exhausted.

 There you have it.  I particularly like where the two water molecules were traveling together (mere microns apart), but were torn asunder and ended up separated by 2,000 miles – the distance from the Hudson Bay to the Gulf of Mexico . . .

 I’ll close with a Panoramio shot (by WeFish) that was taken from the eastern shore of Pickerel Lake (very close to my landing).  We’re looking across the lake at the setting sun . . .

 wefish pano 

That’ll do it.

 KS

 Greg

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