short answer is: no. This has been asked about in the past, and the only way to do it is to specifically request Tribe to do it, but it's highly unlikely that they will.

Hear hear!

I'd much rather see a tribe with two "real" people, than one which lists 47 members, 45 of whom haven't logged in since W's first term.

*boom* "Bring outch'ya dead!" ... *boom* "Bring outch'ya dead!"

>> I have two tribes that NO ONE is interested in joining and I want to erase them.
How is this done? <<

There is a way to delete tribes you moderate. It's not straight forward but some have figured it out, and I have read how to do it. First, you kick out any members that are in the tribe. Then you set the tribe to "private" then you kick out yourself. The tribe now will be no more.

The only thing I wonder with this way of deleting an unwanted tribe, is if someone later on wants to start a tribe and they pick the same name as the one you've deleted in this way, would they be told the name is unavailable?

>> Is there a way to weed out tribes / profiles that haven't had any activity in ...let's say...one year? <<

No, not profiles from tribe.net. Although if you moderate a tribe and want to remove inactive members, and have plenty of time to study all your member's profiles, you can pretty safely figure out which the dead profiles are. I've been doing this with one of my tribes. I went through a membership of well over 500 and any profiles that have not been updated in well over a year, have no recent activity or new pictures or blog entries, and also no testimonials in well over a year. Almost 100 of the 550 or so fit this description, what I would think are inactive profiles. Their names went on a list, and I checked them regularly to see if their orange dot was ever on. Maybe they just don't ever post anything or update their profile. Or perhaps they have removed the recent activity module and also never update nor add photos. I'm trying to give them every chance to prove they are still around. Maybe they have turned off their indicator light for when they are logged on.

So I removed 20 or so that looked like they never went past the first day or two of making their profile, no activity what-so-ever after that after checking for a few weeks. About 5 were removed from my list, but stayed in the tribe because I eventually saw an indicator light on. 65 are still on my list, almost certainly people who have not looked at tribe.net in well over a year and will probably not come back. I'd kick them out of the tribe eventually, just to thin the tribe down to actual users. But then I read that when Tribe 3.0 comes out it will delete unused profiles (2 years of absence). So I stopped policing my tribe and will let Tribe do it. They will be able to tell for sure, I'm gathering, whether or not a person has logged into their account or not in the past 2 years.

For your third query, I personally would like to see tribes of 1 or 2 people and no activity in over a year go. But Tribe has reasons for keeping them around.

the suggestion of kicking everyone out then yourself does the trick, Tribe Terminated...