Due to the Great Circle effect, the shortest path between northern cities curves upward over the polar regions, not a straight line across the Atlantic.
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The 'Great Circle' route that appears curved on a flat map represents:
The Amur Line, following the Amur River, forms much of the border between Russia and China in the Far East. Established through treaties like the 1858 Treaty of Aigun, it has been a historically contested boundary, with the river serving as a natural divider.
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The Antarctic Treaty System sets aside Antarctica as a scientific preserve and bans:
The Antarctic Treaty establishes Antarctica as a region for peaceful scientific purposes, explicitly banning military activity, weapon testing, and mineral mining.
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Which seismic waves are compressional and travel the fastest, arriving first at a seismic station?
P-waves, or Primary waves, are longitudinal compression waves. They travel faster than other seismic waves and can move through solids, liquids, and gases.