<img src="http://farm4.static.flickr.com/3017/2476223436_c9c07a907c.jpg">

This is an ice cauldron on the largest ice cap in Iceland. It was taken by my sister-in law during the summer. This ice cap is at least 500m thick and 120km across.

She informs me that the photo of the waterfall a few posts up is part of Skogafoss, which has two ice caps behind it. She has stayed just by the waterfall and she has also stayed on the ice cap where summer night-time temperatures are below zero -- chiefly because of the ice.

She has popped by here to take a quick look, though she's too busy to join in the discussion; she's teaching people who want to learn about science. She says that there is no understanding of feedback mechanisms here. I don't know what that means so I'm going to find out.