Sizing my avatar pic?? Any Help?

I like to post the occasional humorous type avatar puic...like the one I have now. Problem is that is reduced to a size that makes it practically unreadable, and the humor is lost as people can not read the wording in the cartoon. How can a member make the avatar appear larger?
(It is only taking up half the alloted space allowed for the avatar.)
If a Mod reads this and can do the 'fix' for me without too much distortion, that would be appreciated. Realize some distoration for 'stretching' the pic to make it larger may occur but thats OK as long as it is presentable.
Thanks to all for any suggestions.

We have a certain criteria with avatars and you will see this when you go to upload one.

Note: The maximum size of your custom image is 180 by 180 pixels or 100.0 KB (whichever is smaller).

So if you can make the image more square before resizing it to the forums size then you would have more of your image filling the allotted space.