load-and-preprocess-spatial-data

name	load_and_preprocess_spatial_data
description	Load earthquake GeoJSON and plate boundary datasets, and ensure consistent projection for distance analysis.

To accurately calculate distances, both the earthquake points and the tectonic plate boundaries must be reprojected into an equal-area projected coordinate system (e.g., EPSG:6933 for global equal-area) to ensure distance measurements are in meters.

1. Load earthquakes_2024.json into a GeoDataFrame, setting the geometry from coordinates and EPSG:4326.
2. Load PB2002_boundaries.json and PB2002_plates.json.
3. Filter PB2002_boundaries to select only those segments that border the "Pacific" plate (checking the LeftPlate and RightPlate attributes).
4. Project all GeoDataFrames to a consistent meters-based CRS.
5. Use unary_union on the filtered boundary GeoSeries to create a single geometry object representing the entire Pacific plate boundary perimeter.