The US-Canadian Border and Plate Techtonics
May 29, 2018 9:10 AM Subscribe
A long stretch of the US Canadian border is defined by treaty as the 49th parallel. The border between Vermont and Canada is the 45th parallel. The North American plate is moving southwest by 2-3 inches a year. Does this mean the US is slowly getting land from Canada? If so what happens to this added territory — who owns it? Do we have to move the border posts and fences every few decades?
I checked the USGS website, Customs and Border patrol, and tried numerous Google searches but came up empty.
I checked the USGS website, Customs and Border patrol, and tried numerous Google searches but came up empty.
Best answer: There have been multiple instances where courts ruled that improperly surveyed state borders will still stand, due to the fact that people now rely on these borders.
e.g. State v. Norman. Defendants who had been arrested by WA police north of the 49th parallel challenged jurisdiction, claiming that they were outside the borders defined by the WA State Constitution Article XXIV, and therefore subject to federal but not state law. The WA Supreme Court held that the
e.g. State v. Norman. Defendants who had been arrested by WA police north of the 49th parallel challenged jurisdiction, claiming that they were outside the borders defined by the WA State Constitution Article XXIV, and therefore subject to federal but not state law. The WA Supreme Court held that the
state's northern boundary is coextensive with the international boundary as marked:
At first blush the languageposted by zamboni at 9:53 AM on May 29, 2018 [8 favorites]west along said forty-ninth parallel of north latitudein article XXIV, section 1 appears to refer to the 49th parallel as marked on current maps and as we currently understand it. However, our Enabling Act, treaties and enactments relating to the international border, and the admission of Washington as a state indicate that Congress intended Washington's borders to be the same as those of the Washington Territory; that the Washington Territory's border was the same as the international boundary between the United States and the British possessions to the north; and that the international boundary lay along the 49th parallel as determined in the astronomic survey conducted to carry out the 1846 Treaty of Oregon. The political and conceptual location of the international and state borders was the same when Washington was admitted as a state, and remains so. Legally, the two boundaries are coextensive.
This video is a pretty fun background piece on weird aspects of the US/Canada border, though it does not exactly answer the question.
posted by Mid at 10:06 AM on May 29, 2018 [1 favorite]
posted by Mid at 10:06 AM on May 29, 2018 [1 favorite]
Those are two different border sections, established at different times in the history of British colonization and US creation and expansion.
The border between New York (and Vermont, which was considered part of New York at that point) to the south and Quebec to the north being at the 45th parallel predates the establishment of the 49th parallel clause by decades - it even technically predates the founding of the United States, as the NY/QC border was established in the 1760s. The 49th parallel portion of the border was established in 1818, specifically west of the Northwest Angle in Minnesota, and the boundary east of that landmark remained as it was, give or take. It's not that the boundary itself is moving uniformly south from the 49th parallel to the 45th parallel - that distance is about 275 miles. Presuming average movement of 3 inches per year would mean the plate has only moved about 65 feet since 1760. (Geologists would know better than I if there have been more severe movements in those 260-odd years, but moving 300 miles seems unlikely in that timespan without it being enough of an event that we'd talk about it in US and Canadian history or science courses.)
Wikipedia has a fairly thorough history of the politics of US-Canadian border establishment. We still have boundary disputes, but tectonic plate movement doesn't seem to play much into the politics of it.
posted by Pandora Kouti at 10:25 AM on May 29, 2018 [1 favorite]
The border between New York (and Vermont, which was considered part of New York at that point) to the south and Quebec to the north being at the 45th parallel predates the establishment of the 49th parallel clause by decades - it even technically predates the founding of the United States, as the NY/QC border was established in the 1760s. The 49th parallel portion of the border was established in 1818, specifically west of the Northwest Angle in Minnesota, and the boundary east of that landmark remained as it was, give or take. It's not that the boundary itself is moving uniformly south from the 49th parallel to the 45th parallel - that distance is about 275 miles. Presuming average movement of 3 inches per year would mean the plate has only moved about 65 feet since 1760. (Geologists would know better than I if there have been more severe movements in those 260-odd years, but moving 300 miles seems unlikely in that timespan without it being enough of an event that we'd talk about it in US and Canadian history or science courses.)
Wikipedia has a fairly thorough history of the politics of US-Canadian border establishment. We still have boundary disputes, but tectonic plate movement doesn't seem to play much into the politics of it.
posted by Pandora Kouti at 10:25 AM on May 29, 2018 [1 favorite]
On a much less grand scale, many historic property boundaries in deeds are described by referencing stakes, historic roads that no longer exist, large boulders, neighboring property that may have changed hands and been subdivided... one of the things that surveyors do is essentially translate the language in a deed to a) identify/account for the locations of these historic markers and b) update the land description to modern coordinates, accounting for shifting coordinates and/or coordinate systems. If the logic that the border changes when the coordinates change held true, every border would shift fractionally over the years until your neighbor owned your land.
posted by DoubleLune at 10:50 AM on May 29, 2018 [3 favorites]
posted by DoubleLune at 10:50 AM on May 29, 2018 [3 favorites]
You might also enjoy the story of The Wedge, the one-square mile plot of land between Delaware, Maryland and Pennsylvania.
posted by intermod at 1:51 PM on May 29, 2018
posted by intermod at 1:51 PM on May 29, 2018
The International Boundary Commission is responsible for maintaining the physical border.
"The Commission regularly updates survey data describing the boundary line and the geodetic relationship between boundary monuments. As the boundary is defined by the position of the boundary monuments and other reference markers as they are physically set on the ground, surveys conducted by Commission surveyors do not redefine the boundary, but rather to improve documentary evidence as to its position. Therefore, the constant improvement of the geodetic reference frame of both countries requires the update of geographical coordinates of boundary markers through additional surveys.
"In addition, developments in technology and surveying instruments today allow a level of precision that our predecessors never would have thought possible. That is why you see our surveyors carry out regular surveys of the boundary - not to change its position, but rather to improve its geographic description."
http://www.internationalboundarycommission.org/en/
posted by fso at 1:59 PM on May 29, 2018 [4 favorites]
"The Commission regularly updates survey data describing the boundary line and the geodetic relationship between boundary monuments. As the boundary is defined by the position of the boundary monuments and other reference markers as they are physically set on the ground, surveys conducted by Commission surveyors do not redefine the boundary, but rather to improve documentary evidence as to its position. Therefore, the constant improvement of the geodetic reference frame of both countries requires the update of geographical coordinates of boundary markers through additional surveys.
"In addition, developments in technology and surveying instruments today allow a level of precision that our predecessors never would have thought possible. That is why you see our surveyors carry out regular surveys of the boundary - not to change its position, but rather to improve its geographic description."
http://www.internationalboundarycommission.org/en/
posted by fso at 1:59 PM on May 29, 2018 [4 favorites]
This thread is closed to new comments.
posted by Midnight Skulker at 9:14 AM on May 29, 2018 [2 favorites]