JavaScript
var map = new L.Map("map", {center: [37.8, -96.9], zoom: 2})
.addLayer(new L.TileLayer("http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"));
window.myLayer = L.geoJson().addTo(map);
map.on("mousemove", function(d){
Object.keys(myLayer._layers).map(function(d){ myLayer.removeLayer( myLayer._layers[d] ) })
var plotCoords = [];
// green is the coordinate array for the landmass
var green = [
[-46.76373672, 82.62796021],
[-43.40642548, 83.22515869],
[-39.89751434, 83.18018341],
[-38.62212372, 83.54904938],
[-35.08784866, 83.64512634],
[-27.10043716, 83.51966095],
[-20.84537506, 82.7266922],
[-22.69181633, 82.34165192],
[-26.51750374, 82.2976532],
[-31.89998817, 82.19999695],
[-31.39644814, 82.02153778],
[-27.85665703, 82.13178253],
[-24.84445381, 81.78697205],
[-22.90326881, 82.09317017],
[-22.07174301, 81.73448944],
[-23.16959381, 81.15270996],
[-20.62362289, 81.52462006],
[-15.76816654, 81.9124527],
[-12.77017975, 81.71884918],
[-12.20854855, 81.29154205],
[-16.28531837, 80.58003998],
[-16.84998131, 80.34999847],
[-20.04622841, 80.17707825],
[-17.73034286, 80.12911987],
[-18.89998817, 79.40000153],
[-19.70498276, 78.75128174],
[-19.67351532, 77.63858795],
[-18.47282791, 76.98564911],
[-20.03500748, 76.94434357],
[-21.67941666, 76.62795258],
[-19.83405113, 76.0980835],
[-19.59894562, 75.24838257],
[-20.66815376, 75.15585327],
[-19.3727951, 74.29560852],
[-21.59419632,...