17 December 2008

Topography around my location.

Bayfield Peninsula's elevation and the effect of topography on lake-effect snow of the South Shore.

A month or two ago I was toying with MapSource, the software for hand-held Garmin GPS units. I took four cross-sections of the Bayfield Peninsula, all the cross-sections run through my location on Maple Hill (the central dot in the cross-hairs of the map to the right).


I then took each cross-section and created four elevation profiles:
south-north
west-east

southwest-northeast

northwest-southeast

Four elevation profiles surrounding the Bayfield Peninsula.

The first one is simply a cross-section showing the elevation profile of the Bayfield Peninsula. From the flat line of western Lake Superior in the west, across the sand hills in the middle of the Peninsula, to Chequamegon Bay in the east.


Each elevation profile contains a circled black square where Maple Hill is located on the Peninsula. All things considered, Maple Hill is only a bump on the eastern side of the Peninsula.


The second cross-section shows the elevation profile from the south to the north, with the Penokee Range of Wisconsin in the south, across the White River valley, through the Bayfield Peninsula, ending at Lake Superior in the north.


Compared to the Penokee Range, the Bayfield Peninsula is relatively small. However, this clearly shows how lake-effect snow runs into a "wall" and drops out on the snowbelts. The same ridge runs from the Keweenaw Peninsula of the UP down through northern Wisconsin, though the ridge has higher peaks in certain locations. Up to 1979 feet in Baraga County, MI (Michigan's highest point) and 1872 feet in eastern Ashland County, WI. In comparison, Lake Superior has a water elevation between 600 and 602 (depending on lake level) feet above mean sea level (amsl).

A list of high points for Michigan Counties can be found (here). Wisconsin counties (here).

The third cross-section shows the elevation profile from western Lake Superior to my northwest, through the Bayfield Peninsula, across the Bad River valley and up the Penokee Range in Iron County, WI.

Again, this is the 'wall' that the lake-effect snows run into when the wind blows off the lake.

And finally, the fourth cross-section shows the elevation profile from Wisconsin's Northern Highland Region to my southwest, across the Bayfield Peninsula, and the level of Lake Superior in the Apostle Islands to my northeast.

At first glance, I thought this profile was the least interesting, but I was wrong. The continuity (except the deeply incised river valleys) of the Bayfield Peninsula with the rest of the interior Highland shows that the Peninsula is simply an extension of the interior's topography.

4 comments:

OSNW3 said...

Ok. This is one of your top 3. First off, MapSource, am I able to really use the software w/o a Garmin GPS unit? I read that I could but wasn't willing to take the steps this evening to potentially fail. Second, knowing it will not be as interesting, I want to take the four cross-section and center it over my house.

Top notch, N. I think I've been re-reading this entry and analyzing the graphs for the past half hour.

Ok, I got sided tracked off of one of your ideas. I'll be back.

nathan said...

Thanks, J!

Yep, you can definitely use MapSource sans GPS unit. I didn't use a GPS unit to do what I did in this post (though I do have one and love it). And there are two versions of M.S. that I'm aware of... Metro and Topographic.

If you need any help with M.S. or cross-sections, just let me know! If I have time today, I might play around with your location and see what I come up with. I'll email you if I get a good result.

OSNW3 said...

AWESOME! That would be wonderful.

I'll be driving forth and back from Medford today. Exciting stuff, I know.

NW Wisconsin Weather said...

Cool post! thats looks very interesting! I already looked up the highest point in my county I though it was odd to see it is Frederic. Makes sense though!