Magma Rising at a Seafloor Split

In the picture

1. 1Rock plate edge: solid crust moving away from the gap
2. 2Central crack: an opening where the plates separate
3. 3Rising magma: hot melted rock moving upward from below
4. 4Pillow lava: cooled lava building new seafloor crust

Examples

• Two ice floes drifting apart with water rising in the gap between them
• A loaf of bread tearing open as it rises in the oven

Quiz: Magma Rising at a Seafloor Split (Age 14)

1. 1

   Where does new oceanic crust form?

   • Where two plates slide past each other without separating
   • Where two plates push into each other
   • Where two plates pull apart
2. 2

   At a seafloor split, what does the hot magma do?

   • It stays sealed deep below the plates
   • It pulls the two plates back together
   • It rises upward through the crack
3. 3

   What is true about most of this plate-spreading activity?

   • It happens underwater and stays hidden
   • It only happens in dry desert regions
   • It happens on land where people can watch it

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.