Question

Radiometric dating of a magnetic anomaly stripe of rock that is 225 km away from the mid-ocean ridge axis gives an age of 9 million years. Assuming a constant rate, seafloor spreading in this area occurs at a rate of __________.
A. 5 cm per year
B. 1,012.5 km per year
C. 20,000 cm per year
D. 50 km per year

Answer 1

Answer:

The seafloor spreading in this area occurs at a rate of 5 cm per year.

Explanation:

It is given that, the radiometric dating of a magnetic anomaly stripe of rock that is 225 km away from the mid-ocean ridge axis gives an age of 9 million years.

We need to find the rate at which the seafloor is spreading in this area. The total distance will be, d = 225 km × 2 = 450 km

Time, t = 9 million years

The rate at which the seafloor is spreading in this area is given by :

$v=\dfrac{d}{t}$

$v=\dfrac{4.5\times 10^7\ cm}{9\times 10^6\ year}$

$v=5\ cm/year$

So, the seafloor spreading in this area occurs at a rate of 5 cm per year. Hence, this is the required solution.