Hot springs are common phenomena in Iceland, geysers much less so. One of nature’s truly dramatic spectacles an erupting geyser is a sight never forgotten. The word geyser originates from Geysir — a well known spouting hot spring in Haukadalur.

Geysers are fascinating but the physics behind their eruptions is rather complex. Step forward Amanda Lloyd, a Manchester University undergraduate, who on a recent field trip to Iceland neatly summarised the science in a presentation she gave to the rest of her group. We’re grateful to her for allowing us to reproduce it here.

We do a lot of work with educational groups, usually involving Iceland's rather spectacular geology and geography. It's especially rewarding to see students become enthused by topics that they have hitherto considered rather boring during classroom studies.

For example, just last week the topic of freeze-thaw weathering arose in a rather interesting way. We were with a group of British students when one of them noticed a distinctively split pebble on the ground. Picking it up the student commented that it was rather like a jigsaw and began replacing the split pieces one-by-one. Others joined in, more split pebbles were discovered and it wasn't long before the discussion turned to why these stones looked the way they did. The penny soon dropped; 'freeze-thaw' dimly remembered from a lecture was the explanation and tedious classroom theory was transformed into interesting field knowledge.

Overheard when walking back to our transport: 'You know, even though it's cold, geography's not so boring after all!'