$curauth = (isset($_GET['author_name'])) ? get_user_by('slug', $author_name) : get_userdata(intval($author));
$avatar = get_avatar_url($curauth->ID);

$avatar = get_avatar($curauth->ID, 200, '', '', array( 'class' => 'avatarboxshadow'));
var_dump($avatar);
preg_match('/src="([^">]+)"/',$avatar,$matches);