On the Alaska Peninsula 590 miles southwest of Anchorage, Pavlof Volcano erupts with new intensity, and Veniaminof Volcano, about 60 miles from Pavlof, has continued showing activity since early June, CNN reports.

The volcanoes began with minor eruptions weeks ago and are now showing more intense seismic activity. On Tuesday, the Alaska Volcano Observatory warned of more vigorous activity to come, which will likely mean more ash. There is some lava flowing

Pavlof has been erupting since early May. A snow-covered, cone-shaped mountain, its activity has waxed and waned over the past few months, but is now showing signs of more activity. David Schneider, a geophysicist with the U.S. Geological Survey, told CNN that the volcano has started shaking, and ash has risen at least 28,000 feet high.

"It's a pretty good size, but not high enough to affect overflying aircraft between America and Asia," he said. "It's more of a problem for local aviation." Pavlof is near the town of Cold Bay, a regional transportation hub with a long World War II-era runway that serves flight to the area villages. At times, the volcano's ash has affected those flights.

Schneider said that nearby Veniaminof, a broad mountain topped with a large, flat ice field, began erupting on June 13, producing a lava flow and an ash plume, though not as high as Pavlof's at about 8,200 feet, but they are still intense.

"For some reason we can't explain, it picked up in intensity and vigor," said Tina Neal, an observatory geologist.

"So far there's been trace amounts of ash, so it's just a fine coating," Schneider said, explaining that main hazard right now is ash fall. "Our best estimate of what is going to happen is similar to what's happened in the past - this level of activity and some level of ash."

Scientists say the eruptions of both volcanoes are unrelated.

According to Reuters, ash has dusted the town of King Cove, and the National Weather Service has issued an ash advisory for the region because of breathing problems with people with respiratory ailments and potential damage to exposed electrical equipment.

According to the observatory, a third, more remote volcano, Cleveland Volcano, 940 miles southwest of Anchorage, has begun and on-and-off eruption phase since 2011, but has not produced an explosive eruption since May 6.