Earthquake Choropleth Map
This choropleth map visualizes earthquake counts across U.S. states, using the Albers USA projection and a threshold color scale with a sequential orange-red scheme. The map applies logarithmic scaling to earthquake totals to enhance color distinction, with states colored via `d3.scaleThreshold` and `d3.geoPath` for rendering. Data is loaded from a CSV of state earthquake records and a TopoJSON file of U.S. boundaries, processed with `topojson.feature`. Hovering highlights states in red, though the tooltip code is incomplete and non-functional.