It Burns, Burns, Burns: A New History Emerges for the Pacific Ring of Fire

The graph shows the early stages of the Izu-Bonin subduction zone. Over the past 40 million years, it has moved ever further east. However, bore 2014, provided samples from the region of origin (Philipp Brandl, Geomar)

When Johnny Cash sang about a ring of fire, he may not have known that one actually existed. The “Pacific Ring of Fire,” as it’s commonly known, is another name for the Mariana Trench, a 2,485-mile-long trench stretching from the Mariana Islands to Japan’s Izu-Bonin Islands to northern Japan. Its fiery nickname comes from the intense, undersea volcanic activity in the region, caused by interactions between the Pacific and Philippine Sea Plates.

What caused these interactions, and how long they’ve been happening, has been a matter of scientific dispute for years. Thankfully, the Geomar Helmholtz Center for Ocean Research Kiel teamed up with the Japan Agency for Marine Earth Science and Technology, and the Australian National University, to answer this question by investigating the trench.

Armed with a drill core capable of drilling 5,250 feet deep into the seabed from a depth of 15,420 feet below sea level, the research team was able to take rock and magma samples from a deeper point in the trench that previous efforts.

The drilling vessel Joides Resolution during IODP Expedition 351. (Bill Crawford / IODP)

“For the first time, we were able to obtain samples of rocks that originate from the first stages of subduction,” Geomar’s Dr. Philipp Brandl told Science Daily. He explained that this volcanic zone has been moving east and leaving “important geological traces” behind, but they were too deep underwater to access before. The team’s impressive drill core changed that.

So far, the data they’ve found and analyzed shows that volcanos were active in the Pacific Ring of Fire 30-40 million years ago, and that the subduction zone Dr. Brandl spoke of is at least 50 million years old. They also found that volcanic activity intensified as the zone moved east, and that it began at a time when volcanism was still a relatively new phenomenon.

More data, and thus more drilling, is needed to test the researchers’ observations, but they’ve certainly made encouraging progress. Click here to read their findings in the March edition of Earth and Planetary Science Letters, and scroll down to watch a short Ocean Today feature on the Pacific Ring of Fire.

—RealClearLife Staff