On Friday 11 March 2011, an earthquake measuring 9.0 on the Richter scale triggered a tsunami that devastated parts of coastal Japan. Japan’s Tsunami: How It Happened investigates the science behind the earthquake and tsunami. The programme follows Professor of Geological Sciences Roger Bilham – who arrived in Japan days after the earthquake.On Friday 11 March 2011, an earthquake measuring 9.0 on the Richter scale triggered a tsunami that devastated parts of coastal Japan. Japan’s Tsunami: How It Happened investigates the science behind the earthquake and tsunami. The programme follows Professor of Geological Sciences Roger Bilham – who arrived in Japan days after the earthquake.