Hi Katie - We haven't incorporated tephra morphologic data into our tephra database yet. Please reach out to Kristi Wallace (kwallace@usgs.gov), who manages the Alaska Tephra Lab, as she may have information or ideas that are helpful to your project. Thank you, Cheryl -------- Katie Dyson wrote: Hi there, I am a student from the University of Leeds in the UK and I am currently writing a dissertation on building a tephrostratigraphic for the northern slope of Alaska. I have carried out microscope analysis on two cores collected from Toolik lake and am now trying to identify potential source volcanoes for my findings. I am unable to carry out geochemical analysis as it is too expensive to undertake at my level so the only way I could possibly identify the cryptotephra is by comparing the morphological characteristics to previous recordings. However, I am unable to find this on the website, I can only find geochemical info. Is there any data available on the morphological characteristics of tephra from certain volcanoes and if so please could you point me in the direction of it Any help would be greatly appreciated! Kind Regards, Katie -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050