Some ideas to make this more social media oriented. This would probably be complicated to implement.

We could "like" or "star" people's posts. Users could be ranked by activity and by number of likes. This could help you find new moderators -- people with high activity/likes who are already on the site, might like to work or volunteer as moderators.

We could follow certain users that we like. If I notice someone is always posting great articles, I'd love to "subscribe" to them and get email updates when they post.