The distance the seafloor has spread appears to be the same on both sides of the Mid-Atlantic Ridge but not in the Pacific Ocean off the coast of South America where there is no 90 million year old seafloor. The rate of spreading is faster in the Pacific Ocean than the Atlantic Ocean at around 42.6 millimeters per year, which is faster than the average rate of fingernail growth of 3.5 millimeters per month or 42.6 millimeters per year.

1. 11. In the Atlantic Ocean does the distance that the seafloor grew from the ridge appear to be the
same on both sides? Explain. What about in the Pacific Ocean?
12. Provide an explanation for why there is no 90 Ma seafloor in the Pacific, off the coast of
South America.
13. How does the speed of spreading compare between the Atlantic and the Pacific Oceans? Are
the rates of spreading the same? If not, in which ocean is the rate of spreading faster or slower?
14. According to Wikipedia.com, an average persons fingernails grow around 3.5 millimeters per
month (it would be easy to make this measurement, you would simply need to keep track of how
often you trim your fingernails, and how much you trim). Doing a simple unit conversion, we
can change this rate into one similar to the seafloor spreading calculations, in millimeters per
year
3.5 mm = 3.5 mm x 365 days = 42.6 mm
1 month 30 days 1 yr yr
How does the rate of spreading in the Atlantic and the Pacific compare with the rate of fingernail
growth? Is it faster or slower? Explain.