From Hawaii to the bend in the Hawaiian-Emperor chain is about 4000 km. If the Pacific plate is moving 8.0 cm a year, estimate how long ago the direction of plate motion changed. (The San Andreas Fault in southern California became active at about the same time!)
Does anyone have an answer?
Thank you!
To estimate how long ago the direction of plate motion changed, we can use the given rate of motion of the Pacific plate.
Given:
Distance from Hawaii to the bend in the Hawaiian-Emperor chain = 4000 km
Rate of plate motion = 8.0 cm/year
First, we need to convert the distance from kilometers to centimeters:
4000 km = 4000000 cm
Next, we can divide the total distance by the rate of plate motion to find the time it took for the plate to cover that distance:
Time = Distance / Rate of motion
Time = 4000000 cm / 8.0 cm/year
Calculating this:
Time = 500000 years
Therefore, it is estimated that the direction of plate motion changed around 500,000 years ago.
To estimate how long ago the direction of plate motion changed, we can use the rate of plate motion and the distance between Hawaii and the bend in the Hawaiian-Emperor chain.
First, let's convert the distance from kilometers to centimeters. Since 1 kilometer is equal to 100,000 centimeters, the distance becomes 4000 km * 100,000 cm/km = 400,000,000 cm.
Next, we divide the distance by the rate of plate motion to find the time it took for the plate to move that distance. So, 400,000,000 cm / 8.0 cm/year = 50,000,000 years.
So, based on this estimation, the direction of plate motion changed around 50 million years ago.
This sounds more like geology (or planetary studies) than astronomy.
Presumably the direction of plate motion changed where there is a bend in the chain. So..
Divide 4000*10^3 m by 0.08 m/year.
You get 50 million years.