Mount Cleveland in July of 2016 (Photo by John Lyons/AVO/USGS)Cleveland Volcano in the Aleutians near Unalaska is restless. Scientists at the Alaska Volcano Observatory observed that a new lava dome formed in the summit crater over the weekend, and lava is trickling out. The dome is about 4200 square meters, a little smaller than 10 NBA basketball courts.Listen now“This happens relatively routinely at Cleveland that we grow small little lava domes,” Dave Schneider, a geophysicist with the AVO, said. “They’re kind of shaped like a pancake in the summit crater. Those typically exist for weeks to months before they’re blown up and we start the process all over again.”It has been about a decade by Schneider’s estimate since Cleveland has exploded with a significant amount of lava. This pattern of building pressure and spewing small amounts of lava is one it goes through frequently.“We grow somewhere between one to two to three domes per year it seems. Sometimes there’s more, then less. In 2017, we’ve had at least three periods of dome growth, the last of which was in August. That was destroyed by an explosion,” Schneider said.Even though Cleveland’s explosions are frequent, its pattern does not give scientists much clue as to when this new dome will explode. It could be a matter of days or months.The AVO can detect explosions with the limited monitoring equipment they have on the island. When Cleveland does explode they work with the Federal Aviation Administration and National Weather Service to get word out about ash clouds and other potential aviation dangers.