GEOLOGY

Detailed explanation-1: -Tectonic plates not only move land masses, they also move oceans! This is because both continents and oceans are on the Earth’s crust. You may imagine that these plates are zipping along, but in fact, they are moving VERY SLOWLY! Some move as slowly as 10–40 mm/year.

Detailed explanation-2: -Earth’s land masses move toward and away from each other at an average rate of about 1.5 centimeters (0.6 inches) a year. That’s about the rate that human toenails grow!

Detailed explanation-3: -Because tectonic plates move very slowly-only a few centimeters per year, on average-it takes a long time to observe changes. Scientists have found that the planet’s continents will likely again be joined together in about 250 million years.

Detailed explanation-4: -As the seafloor grows wider, the continents on opposite sides of the ridge move away from each other. The North American and Eurasian tectonic plates, for example, are separated by the Mid-Atlantic Ridge. The two continents are moving away from each other at the rate of about 2.5 centimeters (1 inch) per year.

Detailed explanation-5: -They can move at rates of up to four inches (10 centimeters) per year, but most move much slower than that. Different parts of a plate move at different speeds. The plates move in different directions, colliding, moving away from, and sliding past one another. Most plates are made of both oceanic and continental crust.