Explore the time cutoff
The slider reveals events up to a chosen UTC cutoff. Play advances the cutoff through the requested interval; pause or drag it to inspect a particular period. The underlying downloads still contain all events in the complete result.
A cluster appearing quickly in an animation can be visually striking. The animation speed is a presentation choice, not a physical rate or probability. Read the event times and filters before making a statement about changes in activity.
Understand the scatter view
The view positions catalog points using latitude and longitude around the selected center. It is a simple geographic scatter plot with a grid, not a terrain, fault or shaking map. Longitudes are wrapped around the center so searches near the date line remain usable.
Circle size follows reported magnitude within a bounded display range. Circles can overlap and are not drawn to represent the physical size of a rupture or the affected area. Locations also have uncertainties that this simple chart does not model.
Share a chart with its context
The downloadable SVG includes a source label, center and query radius. Keep the provenance file or state the dates and magnitude threshold beside the image when using it in a lesson or report. Do not crop away the historical-catalog explanation.
A blank result means no records met this particular query, not that no earthquake has ever occurred there. A historical pattern is not a building-safety verdict or a forecast. Direct safety questions to appropriate local and national authorities.