When earthquakes occur, we often focus on the “big one,” but it is interesting to explore other nearby earthquakes to gain a broader perspective on spatial and temporal seismic patterns underground. Using the most current earthquake GeoJSON feed from the US Geological Survey (USGS), this app visualizes the largest earthquake that occurred anywhere in the world within the last week along with all smaller earthquakes from the same area and time period.
In addition to earthquake locations, the USGS feed contains links to multiple supporting GeoJSON datasets, which are dynamically loaded by the API. One of these datasets, a shake map, indicates the intensity of ground shaking surrounding an earthquake. The shake map is thematically drawn using a 3D path symbol with a continuous color ramp that indicates the intensity of each band.
To let users explore above and below ground, earthquakes are visualized in a 3D scene that includes a clipped area of imagery for the land above the earthquake epicenter. With the app’s time slider, users can progressively display earthquakes that occurred throughout the week. With each adjustment of the time slider, the time extent changes and data is filtered accordingly. Because the time slider works with the data on the client side, map updates happen instantaneously.