It’s a good thing for oil spill science that Richard Camilli was not yet on a flight to Australia when the Coast Guard called last May. An hour later and Camilli might have missed the urgent request to get a team together to measure the month-old leak from the Deepwater Horizon pipe. In a richly detailed and highly accessible talk, Camilli describes novel research he performed in the depths of the Gulf to quantify the disaster, helping to settle heated conflicts swirling around the oil gushing from BP’s broken well head. In addition to its vast scale, the spill posed other uniquely challenging conditions, says Camilli: the well’s depth of 5,000 feet required robotic tools for examination or intervention, and enormous undersea pressures encouraged the formation of hydrate crystals, as a mix of oil, gas and other chemicals shot out of the pipe at high temperature, and mixed with much cooler water. Through technological innovations, Camilli was able to measure the flow rate of this “multiphase fluid” as it spewed from the well. With specially rigged equipment, Camilli’s team “listened” to fluid velocity, and imaged the flow with sonar, putting both kinds of measurements together to arrive at the volumetric flow rate. Camilli calculated a daily flow rate for oil from the well, and then its total output, and came up with a net leak of 4.2 million barrels. He also learned that oil from this deep reservoir contained a large fraction of gas, an important finding in terms of environmental impact. While running this research, Camilli discovered a coherent “oil emulsion layer,” a subsurface plume, which he was able to investigate nearly immediately due to a fast turnaround government grant. This time, Camilli deployed a NASA-designed, free-swimming, autonomous undersea device (AUV), which runs a preprogrammed mission then “swims to the surface and waits to be picked up.” Using the AUV, Camilli tracked the plume “meandering along the continental shelf” at around 1,100 meter...