‘IS ASH FALLING?’, AN ONLINE ASHFALL REPORTING TOOL

The primary volcano hazard in Alaska is ash produced during explosive eruptions. Airborne ash endangers aircraft flying the busy North Pacific air routes and consequently can impact both safety of flight and global commerce. Downwind ashfall is also a significant threat to commerce, transportation and day-to-day activities in nearby Alaska communities. For decades, the Alaska Volcano Observatory (AVO) has enlisted the public’s assistance in making observations and collecting ashfall samples during eruptions to help (1) inform government-issued formal hazard advisory products and (2) understand basic information about the eruption and its products. Observer reports of ash fallout are among the best sources of information because they can include details about the timing, duration, amount, and nature of the deposit over vast geographic areas, giving scientists a more complete record of the ash fallout event. Observers also often provide pristine samples of the ash deposit which are used to characterize the ash, assess potential impacts, and in some cases help determine total eruptive volume. Timely observations of ashfall improve public ashfall warnings and forecasts by providing on-the-ground validation of models of ash dispersion and fallout and interpretation of satellite imagery.

A database with a web-accessible interface, "Is Ash Falling?" has been developed at the Alaska Volcano Observatory to more efficiently collect and disseminate ashfall observations and encourage sample collections from the public during eruptions. The database allows: (1) large numbers of people across wide geographic areas to report ashfall without direct interaction with Observatory staff, (2) collation of multiple reports into a single document for quick viewing and analysis, (3) visualization of ashfall reports on a map base for internal and public viewing, and (4) streamlining of data communications among partner agencies by enabling web-based viewing of ashfall data.

Since premiering online in July 2013, AVO has used the ashfall reporting database during several small eruptions with ashfall and finds it to successfully streamline data collection and dissemination and looks forward to testing its utility during a major eruption such as from a Cook Inlet volcano.