One way to monitor global warming is to compute the average temperature of the ocean. Researchers are doing this by determining the time it takes sound pulses to travel underwater over large distances. At a depth of 1000 m, where ocean temperatures hold steady near 4 degrees Celsius, the average sound speed is around1480m/s. It is known from laboratory measurements that the sound speed rises 4.0 m/s for every 1.0 degrees Celsius raise in temperature. In one experiment, where sounds produced near California are detected in the South Pacific, the sound waves travel 7900 km.
If the smallest time change which can be reliably detected is 1.0 s, determine the smallest change in average temperature which can be measured?