The 8.9-magnitude Japan earthquake is associated with the so-called “ring of fire,” according to Gary Solar, geologist and associate professor and chair of earth sciences and science education.

“The ring of fire is an area in the Pacific Ocean where two tectonic plates are converging,” said Solar. “One plate is sliding under another, but it’s not a smooth process. For the most part, they are pressing against each other, creating a great amount of friction. When they slip, it causes an earthquake.”

Both the earthquake and the tsunami are phenomena caused by the slippage, Solar explained, because the plates are converging beneath the ocean floor. “When the fault slips,” he said, “the water moves vertically rapidly.” The severity of both the earthquake and the tsunami result from the enormous amount of energy released. Today’s quake occurred about six miles below the planet’s surface, and just 80 miles off the coast of densely populated Japan.

“Earthquakes have been occurring with pretty much the same frequency throughout planetary history,” said Solar. “However, today, when something like this happens in a heavily populated, modern country, the news is communicated almost instantaneously.”