OpenStreetMap
Square north of Highway 8 in Minnesota, USA - Quarry or HVDC electrode
Posted by Obelixx on 8 October 2012 in English.I believe, that the square north of Highway 8 in Minnesota, I marked with http://www.openstreetmap.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 http://www.openstreetmap.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.
Discussion
Comment from jumbanho on 8 October 2012 at 23:04
The Bing imagery looks like a peat moss quarry to me.
Comment from jumbanho on 9 October 2012 at 13:54
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.