Create and style clusters

Use Mapbox GL JS' built-in functions to visualize points as clusters. See the example: https://docs.mapbox.com//mapbox-gl-js/example/cluster/

HTML

<script src="https://api.mapbox.com/mapbox-gl-js/v1.12.0/mapbox-gl.js"></script>
<link rel="stylesheet" href="https://api.mapbox.com/mapbox-gl-js/v1.12.0/mapbox-gl.css">

<div id="map"></div>

CSS

body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }

JavaScript

mapboxgl.accessToken = 'pk.eyJ1IjoiY2RhdmlzNCIsImEiOiJjazhnNDE0ZXQwYXNkM2xwZjk0emNvZTVzIn0.QXOt9g2X5mFX_GMusi_v6A';
    var map = new mapboxgl.Map({
        container: 'map',
        style: 'mapbox://styles/mapbox/dark-v10',
        center: [-103.59179687498357, 40.66995747013945],
        zoom: 3
    });

    map.on('load', function () {
        // Add a new source from our GeoJSON data and
        // set the 'cluster' option to true. GL-JS will
        // add the point_count property to your source data.
        map.addSource('earthquakes', {
            type: 'geojson',
            // Point to GeoJSON data. This example visualizes all M1.0+ earthquakes
            // from 12/22/15 to 1/21/16 as logged by USGS' Earthquake hazards program.
            data:
                {
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"features": [
{ "type": "Feature", "properties": { "id": "ak16994521", "mag": 2.3, "time": 1507425650893, "felt": null, "tsunami": 0 }, "geometry": { "type": "Point", "coordinates": [-118.497, 34.299667, 0.0 ] } },
{ "type": "Feature", "properties": { "id": "ak16994519", "mag": 1.7, "time": 1507425289659, "felt": null, "tsunami": 0 }, "geometry": { "type": "Point", "coordinates": [ -118.497, 34.299667, 105.5 ] } },
{ "type": "Feature", "properties": { "id": "ak16994517", "mag": 1.6, "time": 1507424832518, "felt": null, "tsunami": 0 }, "geometry": { "type": "Point", "coordinates": [-118.497, 34.299667, 0.0 ] } },
{ "type": "Feature", "properties": { "id": "ci38021336", "mag": 1.42, "time": 1507423898710, "felt": null, "tsunami": 0 }, "geometry": { "type": "Point", "coordinates": [ -118.497, 34.299667, 7.64 ] } },
{ "type": "Feature", "properties": { "id": "us2000b2nn", "mag": 4.2, "time": 1507422626990, "felt": null, "tsunami": 0 }, "geometry": { "type": "Point", "coordinates": [ -118.497, 34.299667, 46.41 ] } },
{ "type": "Feature", "properties": { "id": "ak16994510", "mag":...