evo-geospatial-earthquake-distance

Complete pipeline for finding the earthquake furthest from a tectonic plate boundary within the plate.

Key Concepts

USGS GeoJSON Format

• Root: FeatureCollection with features array
• Each feature: id (string), properties (mag, place, time in ms epoch), geometry (Point with [lon, lat, depth])
• Time is milliseconds since Unix epoch, convert with pd.to_datetime(ms, unit='ms', utc=True)
• ISO 8601 format: strftime('%Y-%m-%dT%H:%M:%SZ')

Pipeline Steps

1. Parse earthquakes, store original lat/lon, shift geometry to 0-360
2. Spatial join with plate polygon using predicate='within' (not op)
3. Reproject to EPSG:3832 (PDC Mercator) for metric distances
4. Compute distances via GeoSeries.distance(boundary_geom) broadcast
5. Find max distance earthquake, format and export

Output Format

{
  "id": "earthquake_id",
  "place": "location description",
  "time": "YYYY-MM-DDTHH:MM:SSZ",
  "magnitude": 5.88,
  "latitude": 19.1868,
  "longitude": -155.4932,
  "distance_km": 4143.49
}

Functions

parse_usgs_earthquakes(path) -> GeoDataFrame

Parses USGS GeoJSON. Stores original lat/lon columns. Shifts geometry to 0-360.

filter_earthquakes_within_plate(eq_gdf, plate_gdf) -> GeoDataFrame

Spatial join with predicate='within'.

compute_boundary_distances(eq_gdf, boundary_geom) -> Series

Reprojects to EPSG:3832, computes distances in km.

find_furthest_earthquake(eq_gdf, distances_km) -> Series

Finds earthquake with maximum distance.

format_and_export_result(row, output_path) -> dict

Formats to JSON with ISO 8601 time, original coordinates.

Usage

import sys
sys.path.insert(0, '/app/environment/skills/evo-geospatial-antimeridian-plates/scripts')
sys.path.insert(0, '/app/environment/skills/evo-geospatial-earthquake-distance/scripts')

from utils import load_plate_polygon, load_plate_boundaries
# Rename to avoid conflict
import importlib
import utils as eq_utils

# Or more explicitly:
from utils import parse_usgs_earthquakes, filter_earthquakes_within_plate
from utils import compute_boundary_distances, find_furthest_earthquake, format_and_export_result