Oregon State University research associate Jochen Braunmiller said during the last two years, more than 360 earthquakes have occurred in the general vicinity of Maupin for elusive reasons, The (Portland) Oregonian said.
The College of Oceanic and Atmospheric Sciences researcher said while one theory focuses on water level shifts miles underground, scientists are at a loss to offer predictions regarding the quakes.
"It just kind of keeps going," Braunmiller said. "Overall, we know stress is being released so we think it will stop at some point. But we cannot say when that will happen or whether we have seen the largest one yet."
The Oregonian said the earthquakes have been focused around the Deschutes River, an area of Oregon filled with volcanic basalts.
Braunmiller told the newspaper that the Eastern California Shear Zone could play a role in the ongoing quakes if the expanding San Andreas Fault is putting sufficient geological pressure on the shear zone.