On Nov. 5, geologists noted changed emissions and minor melting near the Redoubt summit and raised the threat level from green to yellow. It jumped to orange — the stage just before eruption — on Sunday in response to a sharp increase in earthquake activity below the volcano.Interestingly, Alaska's Volcano Observatory website is so swamped right now that it's posting this message:
Due to very high load on our web server, we can only support a very limited website. We are working to remedy the situation as quickly as possible. Thanks!
If you're as curious about the scheme behind the treat levels, there is a nice explanation on Wikipedia. Realizing that information on Wikipedia can be somewhat fleeting, let me provide the warning scheme here:
|GREEN||Volcano is in its normal "dormant" state|
or, after a change from a higher level: Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state.
|YELLOW||Volcano is exhibiting signs of elevated unrest above known background levels.|
or, after a change from a higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.
|ORANGE||Volcano is exhibiting heightened unrest with increased likelihood of eruption,|
or, Volcanic eruption underway with no or minor ash emission (specify ash-plume height if possible).
|RED||Eruption is forecast to be imminent with significant emission of ash into the atmosphere likely.|
or, Eruption is underway with significant emission of ash into the atmosphere (specify ash-plume height if possible).
|BROWN||Cataclysmic eruption is in progress.|