![Naked Scientists Special Editions show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/034/511/small/naked-scientists-special-editions.png)
Summary: This week in the Planet Earth Podcast, how last year's eruption of the Eyjafjallajkull volcano in Iceland gave scientists an unparalleled opportunity for research, and why sediment from rivers like the Thames can act like time machines to bygone eras.