Getting blog thumbnails to click out externally OR disabling click-through on the thumbnails all together

I've set up a writing portfolio using a blog template, but I want almost all of the posts to click out to my work housed on the source URLs. When I click the titles of the posts, it's fine and opens in a new tab. But when I click on the images, they bring me into a Square Space blog page that's basically blank, or it might bring me straight to the source but not in a new tab. I just want to be able to control where the thumbnails as well as the titles bring you when clicked. If the thumbnails can't click out externally, does anyone know of a way to disable them in the Moksha template? I've seen people ask about doing this in Tudor but the solution didn't work for me. Any help is greatly appreciated — my site is www.annemariecrosthwaite.com.

Thank you!