As the second anniversary of the Tohoku earthquake and tsunami nears, the writer Gretel Ehrlich considers what nature wrought and how humans responded. She made three trips to Japan's ravaged northeast coast in the months following the quake, trying to fathom the magnitude of what happened. Her new book Facing the Wave: A Journey in the Wake of the Tsunami is part post-disaster travelogue, part meditation on death, life and impermanence.