ALASKA TEPHRA DATABASE

In 2014, staff at the Alaska Division of Geological & Geophysical Surveys (DGGS) and USGS Alaska Tephra Lab within the Alaska Volcano Observatory (AVO) began construction of an Alaska tephra database. The goal of this effort is to develop the first-ever comprehensive database of Quaternary tephra in Alaska. This database will house all pertinent information on Alaska tephras necessary for sample processing, archiving, and scientific research. Developing correlations of tephra records across Alaska and the northern hemisphere requires an understanding of the age, chemistry, and character of tephra deposits.

Accomplishments to date include: (1) loading of test datasets; (2) ability to query glass geochemical data by sample ID, source volcano, and glass chemistry; and (3) computation of glass chemistry similarity coefficients for multiple tephra samples. Work in progress consists of: (1) sorting tephra datasets in preparation for geochemical and sample metadata upload; (2) developing a streamlined upload process for new data; (3) developing a database schema to store age data; and (4) developing a database schema to hold sample fraction information. Adding data from large, prominent Alaska eruptions is a priority of our data loading effort. Additional project goals include expanding the database to store sample preparation details and individual grain-point and mineral analyses, and creating a laboratory database interface for post-field sample preparation.

Tephra studies are a key component in understanding the magnitude and frequency of volcanic eruptions and help improve volcanic ash fall hazard assessments. In addition, tephrostratigraphy is an integral part of linking marine, lacustrine, and terrestrial records to aid research in paleoclimate studies and archaeology. Currently, Alaska tephra chemical, stratigraphic, and age data are dispersed in hundreds of publications and unpublished lab results, making efficient querying of data for specific research purposes difficult. Creating and populating a single, comprehensive tephra database and developing web portals for easy access will alleviate this difficulty, and make Alaska tephra data more accessible to other scientists.