"It's largely the Pacific plate that makes up the majority of it," Yeck said.
But the ring also includes the Philippine Sea plate, Juan de Fuca and Cocos plates, and the Nazca Plate.
The tectonic plates fit together like a puzzle, but are constantly moving and colliding with each other, thus producing numerous earthquakes.
In addition to the volcanic eruption in Japan and the earthquake in Alaska, a magnitude 6.1 earthquake occurred off the southern coast of Java, Indonesia's mainland, on Tuesday. Also Tuesday, Mount Agung in Bali and Mount Mayon in the Philippines blew their tops, spewing red-hot lava and causing the evacuations of thousands of people.