Hi John, I received your email but it will likely take me until the end of the week to give you a proper answer. I'll get back to you soon, -Janet -------- John Werner wrote: I am the installation Emergency Manager at Joint Base Elmendorf-Richardson and am validating information that I am using for a risk assessment. I know that volcanic ash seldom reaches the JBER area in any significant amount, but could you attempt to quantify that for me? I am basically trying to verify the probability of occurrence (1-10 years, 10-100 years, etc. Thank you very much. SMSgt John Werner USAF, JBER Emergency Mgr