Hi,
Based on the reading I've done, you should be able to change your avatar settings in Disqus (see
http://docs.disqus.com/help/76/ for more on avatars). Log into Disqus, then click on "account settings" (Disqus.com/account/) and then click on the tab that says "Avatar." Then choose the option you want. You can upload a new avatar or use the site's default avatar (which is a generic grey head). You may also use your Facebook or Twitter picture. I hope this helps. Let me know if I can be of further assistance.
-moderator
@amewa_silk: Go back to change it - where? I had no option to pick an avatar in the first place, and I'm not sure how it picked up the one that it did. That's a big part of the problem, it randomly picked an avatar from a totally different site.
@Moderator: Thanks for looking into this. I can't follow your suggestion, however:
I can't log into Disqus at all - I never registered for it. (The signup form makes it clear from the first few questions that "signing up" is only to "register [my] site to use Disqus".) The "forgot password" option correspondingly does nothing, since there's no account for me at Disqus.
The "change settings" option next to my name on the comment form on an article page only gives me an option to enable "Email notifications". (Notification that someone's replied to my comment? That a new comment has been posted on the same article? That someone's "liked" it? Doesn't say.)
I can log out (of my Chronicle.com account) and "create an account" - but that's just for chronicle.com, not for Disqus. (Or I can "connect with Facebook". Yay.)
Despite having changed the email account on my Chronicle account to a brand new one created specifically to test this, Disqus still remembers my other avatar. I seem to be locked into this "connected community" without an escape.