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

const mapElement = document.querySelector('gmp-map')!;
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' &&
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        typeof (f.properties as any).mag === 'number'
    );
}

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

    innerMap = 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: (): [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);
}

void init();

JavaScript

// Import the needed libraries.
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 init() {
    //  Request the needed libraries.
    await google.maps.importLibrary('maps');

    innerMap = 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: () => {
                    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);
}

void init();

CSS

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

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>
        <script>
            // prettier-ignore
            (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: "GOOGLE_MAPS_API_KEY"
            });
        </script>
    </head>
    <body>
        <gmp-map center="40, -110" zoom="4" map-id="DEMO_MAP_ID"></gmp-map>
    </body>
</html>

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. You will also need a Google Maps API key.

The following commands clone the repository, install dependencies, and copy the environment file. 

  git clone https://github.com/googlemaps-samples/js-api-samples.git
  cd js-api-samples
  npm i
  cp .env.template .env

Once you copy the environment file, make sure to open the .env file and replace <Insert your own development API key here> with your actual API key before starting the sample. 

  cd samples/deckgl-points
  npm start