 Watch and has an Aviation color code of Orange, signifying minor volcanic-ash emissions. The Alaska Volcano Observatory website states:
“Sudden explosions of blocks and ash are possible with little or no warning. Ash clouds, if produced, could exceed 20,000 feet above sea level. If a large ash-producing event occurs, nearby seismic, infrasound, or volcanic lightning networks should alert AVO staff quickly. However, for some events, a delay of several hours is possible. Cleveland Volcano does not have a local seismic network and is monitored using only distant seismic and infrasound instruments and satellite data. AVO will continue to monitor the volcano and issue additional information as available.”
Notifications for the volcano can be found at the Cleveland volcano page.
Forecasting and managing
When volcanoes spew ash and other atmospheric particulates into the sky, the airborn pollutants can promote cooling by causing less sunlight to successfully pierce the atmosphere. Volcanoes can have a potentially significant impact on global climate. They can also impact human health by altering air quality.
Forecasting eruptions and managing the effects of eruptions is a big job, and the AVO uses a diverse set of monitoring tools to accomplish the tasks. While some volcanoes have local seismic networks in place that notify scientists of earthquakes and surface deformation caused by magma bulging under mountain flanks, Cleveland has no local seismic equipment. A webcam points its way, but cloudy or severe weather often obscures the mount. The scientists make use of distant seismic networks located at other volcanoes to monitor Cleveland’s explosions. They also engage the increasingly comprehensive coverage available from satellites with sensors for visible light as well as thermal cameras that measure the heightened temperatures common to eruptions. At other times, researchers must rely on eyewitness reports from mariners or airplane pilots.
Seismic stations measure shaking in Earth’s crust. Where the Pacific and North American tectonic plates meet, one plate is subducted under the other. Their grinding super-heats and melts rock, forming magma and applying intense pressure to Earth’s crust. That pressure can cause tremors. Magma forced upward by the pressure can erupt through volcanoes. That motion is measured by seismometers.
Meanwhile, infrasound detectors detect airwave signals which indicate volcanic activity. These instruments pick up the low-frequency sounds emitted by eruptions, the pressure, explosions, and motion of underground magma. Emitted at a low frequency of less than 20 hertz, the noises are much too deep to be picked up by human ears. However, the noises can be picked up by instruments at stations very far away from where they originate, including stations at the University of Alaska Fairbanks Geophysical Institute.
“It’s a difficult volcano for us to monitor… we only get these reports every now and then, or satellite data. The weather out there is horrible. It’s the central Aleutians, the weather is always bad. [Cleveland] could be erupting little puffs, tiny puffs of ash, on a weekly basis and we would just have no clue. It’s kind of a low-level, almost constantly active volcano. I mentioned that different volcanoes have different personalities -I mean some volcanoes are quiet quiet quiet, have a really big eruption, and go back to sleep- Cleveland is always sort of restless, and giving little belches and things like that. It rarely puts ash up very high or for very long periods of time, so in that sense it’s not as hazardous as some of the volcanoes that have larger eruptions, but it’s a bit of a nuisance for us.” ~ Michelle Coombs, research geologist, Alaska Volcano Observatory
Watch FrontierScientists video Volcano From Space: An astronaut aboard the International Space Station spots an eruption and contacts the Alaska Volcano Observatory.
Laura Nielsen 2013
Frontier Scientists: presenting scientific discovery in the Arctic and beyond
Cook Inlet Volcanoes project
- ‘Activity at Cleveland Volcano, Aleutia