Mount Cleveland Lava Dome Grows 25%
The lava dome covering Mt. Cleveland volcano in Alaska has grown by 25 percent since last week. The dome was reported to be 40 meters across on Monday Feb. 6., and has now increased to 50 meters in size, according to the Alaska Volcano Observatory (AVO).
“We got indications from satellite data that the dome had grown slightly,” Alaska Volcano Observatory Research Geologist Matt Haney said. “The recent expansion shows that growth has not ceased.”
The current lava dome is much smaller than the dome was before the last eruption of Mt. Cleveland.
“The previous lava dome that was removed by explosive activity on Dec. 25 and Dec. 29 covered most of the 200-meter-diameter summit crater. So, indeed it was larger than the current dome,” said Haney.
Given that the current lava dome is still significantly smaller than the dome in December, does that mean the explosion would be smaller if it happened from this smaller lava dome?
“No, a larger dome doesn’t necessarily mean a larger yield from the explosion,” said Haney. “We’re still expecting the same type of altitude for the ash cloud. It should interrupt Trans-Pacific flights.”
Satellite radar image from the TerraSAR-X sensor, showing the summit of Cleveland Volcano. Image collected on Feb. 10, 2012, and shows the presence of a small lava dome within the summit crater. The summit crater is about 200 meters across. Note that satellite radar images have some inherent topographic distortion due to the manner in which they are collected. Alaska Volcano Observatory
The new lava dome is still expanding, but when it is finished, it could stay inactive for years.
“This recent expansion shows that the growth has not ceased,” said Haney. “Eventually, there will be a final dome. When the dome in the crater finishes growing, it can stay inactive for quite a while, but this dome is definitely still slowly growing.”
When asked if the dome could still potentially explode, Haney said, “It doesn’t rule anything out. There’s certainly the possibility (with dome growth) that we could see explosions in the future.”
If the volcano erupts, the dome could actually collapse beforehand. The lava dome could become too massive and cave in on itself before an explosion happens.
“Think of it almost like pressing down too hard on a balloon,” said Haney. “The moment before a balloon pops, the outside of it collapses and then the air inside expands outward.”
If you push too hard on a balloon, it will compress before it bursts. Lava domes, similarly, can collapse before they explode. Photo from Photos.com.
The volcano is still at an “orange watch” level, which means the volcano is “exhibiting heightened or escalating unrest with increased potential of eruption,” and the timeframe is uncertain, according to the AVO.
In the event of eruption, the AVO asks you to consult their Ash preparedness website.