Volcano Live

They broadcast from the edge of the summit crater and the Halema'uma'u lava lake. Kate also travels to Iceland to visit Eyjafyallajokull, the volcano which caused air traffic chaos in 2010, and comedian Ed Byrne heads to Bristol university to work out why different volcanoes erupt in different ways.

They broadcast from the site of the 1969 Mauna Ulu eruption which saw more than 17 square miles of lush rainforest covered in lava. Kate also travels to Iceland to the island of Heimeay where a village of fishermen fought a volcano - and won. And volcanologist Hugh Tuffen sends back a video diary of his expedition to Mount Puyehue in Chile.

They broadcast from the town of Kalapana, destroyed 20 years ago by Kilauea's lava flows and look at the connections between volcanoes, earthquakes and tsunamis. Iain visits the Bay of Naples and explains the forces at work behind the most devastating volcanic eruptions. Kate's Icelandic adventure continues as she descends 150 metres into the mouth of a dormant volcano.

Broadcasting from the summit crater, they look to the future of volcanic forecasting. Ed Byrne uses a bin, plastic balls and some liquid nitrogen to mimic a supervolcanic eruption, while Kate finds an Icelandic volcano which could put the eruption of Eyjafyallajokull in the shade.