// click in the locate me button initializes the location service
$('#locate-me').on('click', function(e) {

    e.preventDefault();

    // scroll to the section
    $("html, body").animate({ scrollTop: $("#find-a-shark-club").offset().top - 80 }, 400 ); 

    // initialize HTML5 location service
    self.userLocation();

    // if it takes too long just show locations in a drop down
    self.setTimer();
});    

The geolocation API.

// get the location of the visitor or add the drop down with all locations
this.userLocation = function() {

    if (navigator.geolocation) {

        // on success set the clostes 2 locations, otherwise show drop down
        navigator.geolocation.getCurrentPosition(this.setClosest, this.blocked);
    } 
    else {
        this.blocked();
    }
}

// calculate the closest locations and add the information
this.setClosest = function(position) {

    this.locations = [];

    var pathname = window.location.pathname; 
 
    // Add each location's data to an array        
    for ( var i=0; i < self.data.length; i++ ) {

        self.locations.push({ 
            // calculate distance between user and restaurants
            distance: calcDistance(
                    self.data[i].geo.lat, self.data[i].geo.lng, 
                    position.coords.latitude, position.coords.longitude), 
            postID: self.data[i].postID, 
            title: self.data[i].title, 
            postURL: self.data[i].postURL 
        });
    }

    // sort results by closest location
    self.locations.sort(sortByDistance);

    ...
        
    // add to session storage for use on other pages    
    sessionStorage.setItem('locations', JSON.stringify(self.locations));
           
    // add the information to the homepage 
    if ( pathname == '/' ){
                
        self.appendLocations("/", self.locations);

        self.createHomepageInfo();
    }
    ...
}