Question

Which of the following statements is true?
The Decca navigation system is used today by the U.S. Coast Guard.
SONAR was developed during World War I to track the location of underwater mines.
Seismic profiling uses high frequency radio waves to map the surface of the ocean floor.
All of the above.
None of the above.

Answer 1

Answer:

None of the above.

Explanation:

The Decca system was discontinued in 2001. Loran-C replaced the Decca navigation system which was more accurate. Loran-C uses low frequency radio waves.

SONAR (sound navigation ranging) was developed in World War I for threats like submarines.

Seismic profiling uses frequencies lower than 3 to 30 Hz which is not considered as high frequency.

Answer 2

Answer:

none of the above

Explanation: