Final answer:
Geographic features such as mid-ocean ridges and rift valleys can form as a result of diverging tectonic plates. These areas often exhibit volcanic activity due to mantle material melting when pressure decreases as plates move apart. Isostasy explains the vertical motion of Earth's crust in response to these processes.
Step-by-step explanation:
As a result of diverging plates, several geographic and topographic features can be formed. When the Earth's tectonic plates move apart, this movement can lead to the formation of mid-ocean ridges, such as the Mid-Atlantic Ridge, where new oceanic crust is created by magma that rises from the mantle and solidifies at the surface. Another formation due to diverging plates is the creation of rift valleys, like the East African Rift, which occur on land and can eventually lead to the development of a new ocean basin as the continent splits.
Additionally, as the crust splits and thins during this divergent movement, volcanic activity is commonly associated with it. The decrease in pressure as the plates pull apart allows for the mantle's heated material to melt and form magma, resulting in various volcanic landscapes.
Related to diverging plate boundaries, we also see the phenomenon of isostasy, which is the Earth's crust in gravitational equilibrium. It's comparable to an iceberg floating in the water; this concept helps explain the vertical movement of the Earth's crust in response to loading and unloading due to erosional processes, deposition of sediments, or tectonic activities.