Scientists have raised the threat level of Alaska's Cleveland Volcano from yellow to orange after detecting a lower-level eruption late Saturday morning. Jessica Larsen, with the University of Alaska Fairbanks Geophysical Institute, said scientists had not seen evidence for ash in satellite images. She says there were clouds at 30,000 feet and scientists could not see evidence for ash above that. The volcano is located on an uninhabited island in the Aleutian Islands. The threat level was raised by the Alaska Volcano Observatory. Larsen says that according to an observatory seismologist, this is the 40th explosion at Cleveland Volcano since 2011 and the first since last August.