Question

part a: mid - atlantic ridge data
the table below shows the ages of oceanic crust at different distances from the mid - atlantic ridge.
distance from ridge (km) age of oceanic crust (millions of years)
0 0
100 10
200 20
300 30
400 40
500 50
questions:

1. what happens to the age of the oceanic crust as the distance from the ridge increases?
2. describe the pattern you see in the data.
3. which crust is the youngest? which is the oldest? where are they located?
4. how does this data support the idea of seafloor spreading?
5. if you measured 700 km from the ridge, how old would you predict the crust to be?

Explanation:

1. As the distance from the ridge increases, the age of the oceanic crust increases. This is because new crust is formed at the ridge and moves away over time.
2. The pattern is a linear relationship. For every 100 - km increase in distance from the ridge, the age of the oceanic crust increases by 10 million years.
3. The youngest crust is at a distance of 0 km from the ridge (age = 0 million years), and the oldest crust in the data set is at 500 km from the ridge (age = 50 million years). In general, the youngest crust is located at the Mid - Atlantic Ridge and the age increases with distance from it.
4. Seafloor spreading suggests that new oceanic crust is formed at mid - ocean ridges and moves outward. The data shows that the crust closest to the ridge is the youngest and as you move away, the crust gets older, which is consistent with the concept of seafloor spreading.
5. Since the relationship is linear (10 million years per 100 km), for a distance of 700 km from the ridge, we can calculate the age. The age increase for 700 km compared to 0 km is $\frac{700}{100}\times10 = 70$ million years.

Answer:

1. The age of the oceanic crust increases.
2. There is a linear relationship where the age increases by 10 million years for every 100 - km increase in distance from the ridge.
3. The youngest crust is at 0 km from the ridge with an age of 0 million years. The oldest crust in the data is at 500 km from the ridge with an age of 50 million years. The youngest is at the ridge and age increases with distance.
4. The youngest crust is at the ridge and it gets older with distance, which is consistent with seafloor spreading where new crust forms at the ridge and moves outward.
5. 70 million years.