"Internal waves," large waves that break underwater, can displace the ocean's layers, mixing cold, nutrient-rich water below with the waters above. Matthew Alford of the Scripps Institution of Oceanography introduces these waves, describes the technology used to observe them and discusses their three primary impacts: interfering with submarine navigation, divers and offshore structures; fueling biological production and redistributing algae and larvae by transporting ocean nutrients into shallow coastal regions; and predicting climate change in conjunction with computer simulations of the ocean. Recorded on 11/13/2014. (#29029)