Wednesday, February 24, 2021


Can you guess what this might be?

The rest of the picture:


Unknown said...

A row of dots shooting off to the right looked vaguely familiar when I saw this yesterday, and sleep helped me to link it to the course of the Ohio river. I had been thinking coastline and river system, but not in the right region.

I think what we are looking at must be dots representing something like ship traffic, and we're looking mostly at the Mississippi navigation system above Memphis, along with the great lakes represented by dots that are more scattered instead of in snaky lines.

james said...

We recognize different things. I saw the outline of the border of Illinois off to the left, and once you see that you can see there's a shipping lane to Chicago that I always forget about. It is funny how the rivers have so much more traffic than the Great Lakes.

Unknown said...

The 'so much more traffic" is something I pondered too. I went and found a map of AIS data from today that is pretty close to your image, only also including indication of ships in motion (which most aren't)

The river ships are mostly marked blue, which indicates "Auxiliary Vessel" -- could be and undoubtedly are cargo vessels mostly, but perhaps they are called that because they are much smaller than the ones marked "cargo vessel"? It makes sense that riverine traffic might be many smaller vessels rather than the larger ore freighters and ocean-going vessels common in Great Lakes shipping.

Also, it is February. The locks are closed in the St. Lawrence Seaway, and it is still weeks till the shipping 'season' on the lakes starts up again. A friend posted on the weekend a picture of people cross-country-skiing well out from shore on the ice in Lake Erie, it doesn't freeze all the way over every winter, but as I recall every winter it does freeze enough to end shipping for the winter.

Assistant Village Idiot said...

As a maphead, I should have guessed, but did not.