This visualization shows earthquake locations and magnitudes across the United States over the past week, using a color scale to group magnitudes into ordinal bins. A legend on the right lists magnitude ranges with counts of quakes per bin, and mousing over the map displays geographic coordinates. The code uses d3.geoAlbersUsa and d3.geoPath for the map projection, loads state boundaries from TopoJSON and earthquake data from USGS GeoJSON, and employs d3.scaleOrdinal with d3.schemeCategory10 for magnitude-dependent fill colors.