You Are Doing a Hydrographic Survey by the Sand Heads

Multiple Choice

You are doing a hydrographic survey by the Sand Heads Light, off the mouth of the Fraser River in very silty green water. You lower a bar to check its reflection and calibrate your sounder. You find that the fresh river water has dropped the speed of sound to 1483 m/sec. If the bottom registers at 15 milliseconds (0.015 sec) , how deep is the top of the Fraser delta? Use the equation: depth (m) =

A) 2250 m
B) 11.12 m
C) 22.25 m
D) 11.25 m