RAW VIDEO: Aerial footage of Three Sisters volcanic region in central Oregon

The ground is swelling under the Three Sisters volcanic region in central Oregon.

The U.S. Geological Survey issued a statement that the rate of uplift in an area 12 miles across has risen nearly an inch between June of 2020 and August of 2021. Yet, this latest uplift comes after some 25 years of activity. Scientists say it’s happening as lava is filling a space underground.

“When this happens at volcanoes, there are often these pulses of lava. They kind of push the top of the volcano out. It’s very slight," said Emily Montgomery-Brown, a research geophysicist at the Cascades Volcano Observatory in Vancouver, Washington.

Does this mean an eruption is on its way? Montgomery-Brown said that’s not expected.