Researchers once thought that at any given subduction zone, the diving plate simply curls down into the deep, dropping in a sheet like a curtain, Hawley explains. These collisions often form what are known as subduction zones, where oceanic plates take the plunge while continental plates ride high. They grind against one another, pulling apart at some edges and colliding in others. “But we may discuss this for some years to come.” Teasing apart a tearĮarth’s crust is fractured into an interlocking network of tectonic plates, whose slow-motion dance has shaped the surface of our planet. “I think there are certainly good ideas,” says Martin Streck, a volcanologist at Portland State University who specializes in the geologic activity of the Pacific Northwest. Other scientists are greeting the new model with curiosity and excitement, but they also caution that it needs more testing before it can become geologic canon. ( Find our what might happen when Earth’s tectonic plates grind to a halt.) “What we are looking at right now is the death of an oceanic plate,” Hawley says. What happens when such plates are swallowed up is still unknown-but it’s a fate that awaits all of the planet’s oceanic plates. The Juan de Fuca is one of the few remaining fragments of the once mighty Farallon plate, which North America began languidly consuming some 180 million years ago as the supercontinent Pangea broke apart. What’s more, the study is giving scientists a peek into the final moments of a tectonic plate’s life. Find out the origins of our home planet and some of the key ingredients that help make this blue speck in space a unique global ecosystem. Such a tear could also explain a string of curious volcanism that swoops across a broad swath of Oregon.Įarth is the only planet known to maintain life. For instance, as the southern limb of the split rotates away, its motion could be the cause of strong earthquakes that rattle off the coast of southern Oregon and northern California, the new model suggests. But the presence of such a feature could be the root of a number of hazards at the surface, helping scientists more accurately identify future dangers. “I know that this seems like this little tear is a long way down,” Hawley says.

In a study recently published in Geophysical Research Letters, Hawley and his coauthor Richard Allen suggest that the missing piece is not just a hole, but a tear that’s slowly splitting the plate apart at least 93 miles beneath the surface. Such a feature must be affecting the surface-and he wanted to know how. He wasn’t the first to notice this gap, but it nagged at the back of his brain. Hawley, however, was distracted by a peculiar region below central Oregon where it appears that a chunk of the Juan de Fuca plate is missing. There, the Juan de Fuca tectonic plate plunges under the North American plate, building strain throughout the region and prompting fears of the massive earthquake that could strike when it releases. student at the University of California, Berkeley, Hawley is fascinated with the geologic complexities of the Cascadia subduction zone, a giant fault off the coast of the Pacific Northwest. Something was nagging at William Hawley, and it was more about what was missing than what was there.Īs a Ph.D.

Pacific northwest coast