The great fracture zones of the northeastern Pacific extend into the central Pacific. At a relatively constant distance of 4500 to 4900 kilometers west of the crest of the East Pacific Rise and of its projection through North America, the typically straight and simple fracture zones branch and become more complex. However, the Clipperton fracture zone, including one branch, follows a great circle for almost 10,000 kilometers, a quarter of Earth's circumference.