Google Maps and deck.gl GeoJsonLayer

  • This example demonstrates visualizing a large number of data points, specifically earthquake locations, on a Google Map using deck.gl's GeoJsonLayer and ScatterplotOverlay.

  • It fetches earthquake data from a USGS GeoJSON feed and dynamically renders points on the map, scaling their size based on magnitude.

  • The visualization utilizes deck.gl transitions for a smooth, animated appearance of data points.

  • The code provides both TypeScript and JavaScript implementations, offering flexibility for developers.

  • Users can interact with the visualization through a live demo on JSFiddle or explore the source code via provided links.

Visualize thousands of points

This example visualizes recent earthquakes using the deck.gl GeoJsonLayer and a ScatterPlot of earthquakes.

For more information, see https://deck.gl/.

TypeScript

import { Feature } from 'geojson';
import { GoogleMapsOverlay } from '@deck.gl/google-maps';
import { GeoJsonLayer } from '@deck.gl/layers';

type Properties = { mag: number };

const mapElement = document.querySelector('gmp-map') as google.maps.MapElement;
let innerMap: google.maps.Map;

interface EarthquakeProperties {
    mag: number;
    place: string;
    time: number;
}

/**
 * Validates that a feature has the properties we need for rendering.
 */
function isEarthquake(f: Feature): f is Feature & { properties: EarthquakeProperties } {
  return (
    f.properties !== null &&
    typeof f.properties === 'object' &&
    typeof (f.properties as any).mag === 'number'
  );
}

// Initialize and add the map
async function initMap() {
    //  Request the needed libraries.
    await google.maps.importLibrary('maps');

    innerMap = await mapElement.innerMap;

    const deckOverlay = new GoogleMapsOverlay({
        layers: [
            new GeoJsonLayer({
                id: 'earthquakes',
                data: 'https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson',
                filled: true,
                pointRadiusMinPixels: 2,
                pointRadiusMaxPixels: 200,
                opacity: 0.4,
                pointRadiusScale: 0.3,
                getPointRadius: (f: Feature): number => {
                    if (isEarthquake(f)) {
                        return Math.pow(10, f.properties.mag);
                    }
                    return 0; // Fallback for invalid data.
                },
                getFillColor: (f: Feature): [number, number, number, number] => {
                    return [255, 70, 30, 180]; // Default color for other earthquakes.
                },
                autoHighlight: true,
                transitions: {
                    getPointRadius: {
                        type: 'spring',
                        stiffness: 0.1,
                        damping: 0.15,
                        enter: () => [0], // grow from size 0,
                        duration: 10000,
                    },
                },
                onDataLoad: () => {
                    console.log('Data is loaded.');
                },
            }),
        ],
    });

    deckOverlay.setMap(innerMap);
}

initMap();
index.ts

JavaScript

import { GoogleMapsOverlay } from '@deck.gl/google-maps';
import { GeoJsonLayer } from '@deck.gl/layers';
const mapElement = document.querySelector('gmp-map');
let innerMap;
/**
 * Validates that a feature has the properties we need for rendering.
 */
function isEarthquake(f) {
    return (f.properties !== null &&
        typeof f.properties === 'object' &&
        typeof f.properties.mag === 'number');
}
// Initialize and add the map
async function initMap() {
    //  Request the needed libraries.
    await google.maps.importLibrary('maps');
    innerMap = await mapElement.innerMap;
    const deckOverlay = new GoogleMapsOverlay({
        layers: [
            new GeoJsonLayer({
                id: 'earthquakes',
                data: 'https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson',
                filled: true,
                pointRadiusMinPixels: 2,
                pointRadiusMaxPixels: 200,
                opacity: 0.4,
                pointRadiusScale: 0.3,
                getPointRadius: (f) => {
                    if (isEarthquake(f)) {
                        return Math.pow(10, f.properties.mag);
                    }
                    return 0; // Fallback for invalid data.
                },
                getFillColor: (f) => {
                    return [255, 70, 30, 180]; // Default color for other earthquakes.
                },
                autoHighlight: true,
                transitions: {
                    getPointRadius: {
                        type: 'spring',
                        stiffness: 0.1,
                        damping: 0.15,
                        enter: () => [0], // grow from size 0,
                        duration: 10000,
                    },
                },
                onDataLoad: () => {
                    console.log('Data is loaded.');
                },
            }),
        ],
    });
    deckOverlay.setMap(innerMap);
}
initMap();
index.js

CSS

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
}

style.css

HTML

<html>
    <head>
        <title>deck.gl and Google Maps Platform</title>
        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <!-- prettier-ignore -->
        <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})
        ({key: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8", v: "weekly"});</script>
    </head>
    <body>
        <gmp-map center="40, -110" zoom="4" map-id="DEMO_MAP_ID"></gmp-map>
    </body>
</html>
index.html

Try Sample

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application. 

  git clone https://github.com/googlemaps-samples/js-api-samples.git
  cd samples/deckgl-points
  npm i
  npm start