A prototype of an interactive viewer for aftershock forecast maps based on user needs

Bianca Artigas, Max Schneider, & Anne Wein

Published September 8, 2024, SCEC Contribution #14019, 2024 SCEC Annual Meeting Poster #194

Aftershocks following large earthquakes can be forecasted using statistical models. Forecasts of aftershock rates and ground shaking are released by organizations such as the U.S. Geological Survey (USGS) to communicate the hazards. Currently, aftershock forecasts are communicated using products without consideration of the diverse needs of their users. In 2023, stakeholder workshops were held to elicit perspectives from various professions on how such aftershock forecasts should be visualized. Users frequently requested maps showing the forecasted ground shaking from aftershocks, and ways to interact with these maps. Furthermore, users prioritized different types of probabilistic shaking estimates, map designs and additional geospatial information, based on their post-earthquake decisions or communication needs. Since there are currently few interactive systems to view aftershock forecasts, and none that address users’ specific needs, we present a prototype of an interactive system to appeal to as many user needs as possible. This interactive viewer has three major components: data, map design, and interactive features. To meet users’ request for forecasted ground shaking, we visualized our forecasts of ground shaking (using the Modified Mercalli Intensity (MMI) scale) in two kinds of maps: one showing the probability of exceeding MMI VI (strong shaking) and one showing the MMI level with a 10% probability of exceedance. Different use cases require different forecast durations, so the viewer allows the user to select between forecasts for the next day, week and month. The viewer also allows the user to choose the map’s visual design, including choices for color scheme, data binning, map and legend titles and labels, and heatmap transparency, which are based on user needs and literature-based data visualization practices. Several interactive features are also included, such as the ability to add and remove map layers to visualize fault lines and the locations of the mainshock and earlier aftershocks. Since our shaking maps use a discretized color scheme, we added the ability to click and hover on the map to show the precise forecast value at that location. The user-designed maps may also be downloaded as a PDF for offline use, as per user requests. This interactive system went through several stages of design, testing and review by colleagues at the USGS and partner institutions. The prototyping process is ongoing, and we encourage feedback at our poster.

Key Words
earthquake forecasting, interactive systems, software demonstration, data visualization, maps, statistical seismology

Citation
Artigas, B., Schneider, M., & Wein, A. (2024, 09). A prototype of an interactive viewer for aftershock forecast maps based on user needs. Poster Presentation at 2024 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Forecasting and Predictability (EFP)