Author Question: On the Geologic Time Scale, the time unit representing the largest span of time is the A) ... (Read 51 times)

maegan_martin · **on:** Jul 29, 2018

On the Geologic Time Scale, the time unit representing the largest span of time is the

A) Phanerozoic.
B) Precambrian.
C) Proterozoic.
D) Mega-annum.

Question 2

Why does sea level rise when spreading rate increases?

What will be an ideal response?

aidanmbrowne · **Reply #1 on:** Jul 29, 2018

Answer to Question 1

Answer: B

Answer to Question 2

Answer: Sea level rises because a faster spreading rate means warmer ocean crust (same cooling rate as during periods of slower spreading), which is less dense than colder ocean crust. Since it is less dense, the ocean crust rides higher on the asthenosphere, forcing seawater onto the continents.