Geometric Boundaries

A world map, shows two regions where geometric boundaries are especially prominent: North America and North Africa. These boundaries are peaceful now but were not always so in the past.

Geometric Boundaries: North America

Part of the northern U.S. boundary with Canada is a 2,100-kilometer (1,300-mile) line along 49° north latitude, running from Lake of the Woods between Minnesota and Manitoba to the Strait of Georgia between Washington State and British Columbia (Figure 8-60). Québec’s boundary with New York and Vermont is also geometric, along 45° north latitude. The two countries share an additional 1,100-kilometer (700-mile) geometric boundary between Alaska and the Yukon Territory along the north-south arc of 141° west longitude.

Geometric Boundary: North America

Peace Arch between Blaine, Washington, and Surrey, British Columbia.

The U.S.-Canada boundary was established through a series of treaties between 1783 and 1903 between the United States and the United Kingdom, which then still controlled Canada. During the 1840s, many Americans called for the border between the Rockies and the Pacific to be set further north, at 54°40’ north latitude (the southern tip of Alaska). Advocates of the northern line used the slogan “54-40 or fight,” but the Oregon Treaty settled the dispute peacefully in 1846.

Geometric Boundaries: North Africa

Boundaries between Algeria, Libya, and Egypt on the north and Mali, Niger, Chad, and Sudan on the south are for the most part geometric. Many of these boundaries are a legacy of treaties among European countries to divide up much of Africa into colonies. For example, the 1,000-kilometer (600-mile) boundary between Chad and Libya is a straight line drawn across the desert in 1899 by the French and British to set the northern limit of French colonies in Africa.

As an independent country, Libya claimed that the straight line should be 100 kilometers (60 miles) to the south, to include territory known as the Aouzou Strip (Figure 8-61). Citing an agreement in 1935 between France and Italy, which then controlled much of Libya, Libya seized the Aouzou Strip in 1973. Chad regained control of the strip in 1987, and Libya withdrew its troops after the International Court of Justice ruled in favor of Chad’s claim in 1994.

Geometric Boundary: North Africa

The boundary between Chad and Libya is a straight line, drawn by European states early in the twentieth century, when the area comprised a series of colonies. Libya, however, claims that the boundary should be located 100 kilometers (60 miles) to the south and that it should have sovereignty over the Aouzou Strip.

Pause & Reflect 8.4.3

Where is the U.S.–Canada boundary not based on geometry?

Geometric Boundary: South Pole

The South Pole region contains the only large landmasses on Earth’s surface that are not part of a state. Seven states claim portions of the South Pole region: Argentina, Australia, Chile, France, New Zealand, Norway, and the United Kingdom. These claims are divided geometrically, following meridians that converge on the South Pole

National Claims to Antarctica

Portions of Antarctica are claimed by Argentina, Australia, Chile, France, New Zealand, Norway, and the United Kingdom; claims by Argentina, Chile, and the United Kingdom are conflicting.

Some of the territorial claims are overlapping and conflicting, and on the other hand some of the South Pole region is unclaimed by any state. The United States, Russia, and a number of other states do not recognize the claims of any country to Antarctica. The Antarctic Treaty, signed in 1959 by 47 states, provides a legal framework for managing Antarctica. States may establish research stations there for scientific investigations, but no military activities are permitted.

North Polar Region

The 1982 United Nations Convention on the Law of the Sea permitted countries to submit claims inside the Arctic Circle by 2009 Canada, Denmark, Iceland, Norway, Russia, and the United States make conflicting claims. The heart of the dispute is the Lomonosov Ridge, which runs 1,800 kilometers (1,100 miles) across the polar region. The ridge rises several thousand meters above the floor of the Arctic Sea and in some places is only a few hundred meters below the current sea level. Russia and Denmark (which controls Greenland) both claim the Lomonosov Ridge as an extension of their respective landmasses. The territorial claims around the North Pole are based on differing interpretations of the Law of the Sea, discussed earlier in this chapter.

National Claims to the Arctic Ocean

Under the Law of the Sea Treaty of 1982, countries have submitted claims to territory inside the Arctic Circle. Some of these claims overlap.

Pause & Reflect 8.4.3

1. Why do the countries adjacent to the Arctic Ocean want to claim parts of the seafloor, such as the Lomonosov Ridge?

2. Referring to a globe or world map, explain how the melting of the Arctic Ocean’s sea ice due to climate change could affect global shipping routes.