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Why does continental crust stand higher than oceanic crust?

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volcanology — Earth sciences Geologist using a rock hammer to sample active pahoehoe lava for geochemical analysis on the Kilauea volcano, Hawaii, June 26, 2009.

Continental crust stands higher than oceanic crust primarily due to differences in density and the principle of isostasy.

Continental crust is composed largely of granitic rock, which has a lower density (approximately 2.7 grams per cubic cm) compared to the basaltic oceanic crust (approximately 2.9 to 3 grams per cubic cm). Because it is less dense, the continental crust possesses greater buoyancy, allowing it to float higher within the mantle.1

This relationship is governed by isostasy, the theoretical balance of the lithosphere as it floats on the denser, plastic asthenosphere. Just as an iceberg floats higher or lower depending on its mass and density, the Earth's crustal segments adjust their elevation to maintain gravitational equilibrium. Consequently, the thicker, less-dense continental crust naturally sits at a higher elevation than the thinner, denser oceanic crust.12