OpenStreetMap
Square north of Highway 8 in Minnesota, USA - Quarry or HVDC electrode
Vum Obelixx matgedeelt de(n) 8. Oktober 2012 op English.I believe, that the square north of Highway 8 in Minnesota, I marked with osm.org/browse/way/184791849 is the grounding electrode of HVDC Square Butte, described on http://web.archive.org/web/20051115122807/http://www.transmission.bpa.gov/cigresc14/Compendium/SQUARE.htm and not a quarry. Can a mapper in this area confirm my assumption? Nevertheless, the grounding electrode of Square Butte must be in this area. When you have a close look at the powerline, which uses the pylon osm.org/browse/node/1947051066 you discover, that the line has west of this pylon 3 and east of this pylon 4 conductors, whereby the fourth conductor is the ground return of Square return and runs directly to the converter of HVDC Square Butte at Adolph HVDC Converter Station.
Diskussioun
Bemierkung vum jumbanho de(n) 8. Oktober 2012 um 23:04 Auer
The Bing imagery looks like a peat moss quarry to me.
Bemierkung vum jumbanho de(n) 9. Oktober 2012 um 13:54 Auer
Just as an added hint as to why, first, the soil is fresh suggesting regular activity and second, there are big rolls along the south end which are probably rolls of peat. Third, there are several field entries from the road which are probably used by trucks to pick up the peat. I don’t know much about what grounding electrodes would look like, but I assume they wouldn’t need that many service entrances.