Choose a manageable interval
Start with a moderate radius and a year of data. Lower magnitude thresholds can produce much denser catalogs. The tool supports a maximum of ten years at once, but a shorter period is often easier to inspect and explain.
The end date is inclusive as a calendar date. Internally the query ends at midnight immediately after it, and downloaded rows are filtered using a start-inclusive, end-exclusive interval. This prevents ambiguity when adjacent intervals are combined.
Avoid silent truncation
The provider endpoint is capped at 10,000 entries per response. Reaching that ceiling causes the application to divide the time interval and request its parts. Event IDs remove duplicates and exact boundaries are applied again locally.
The application also has a total event and request budget. If that budget is exceeded, it stops and asks for narrower filters. It does not label the first page as the complete history or hide an unfinished second region behind a successful-looking export.
Preserve the source record
CSV is convenient for spreadsheets, while GeoJSON keeps point coordinates for mapping applications. Longitude precedes latitude in the GeoJSON geometry. Depth remains in kilometers as reported by USGS; it is not converted into an elevation model.
Download the separate provenance JSON alongside the event files. It records the query settings, fetch times and provider URLs. A later query can differ because catalog records are revised, so reproducible communication needs both the filters and the retrieval date.