In your own words, please explain why does the ocean crust sink?

Follow-Up Question- How do you know this? Please use the ESRT page 10 upper right-hand corner.

(Note- The following images down below should be able to help you out a bit if you're having trouble)

1. crust 1 the metallic layer at the earth's center 2. inner core 3 the firm layer between the crust and the asthenosphere 3. lower mantle 2 the layer surrounding the inner core 4. asthenosphere 4 the semi-solid layer between the top layer and the upper mantle 5. upper mantle 5 the layer between the asthenosphere and lower mantle 6. top layer 6 the earth's outermost layer 7. outer core 7 the hottest part of the mantle

What causes heat transfer in fluids

Since 1980, which three countries have either attacked or been attacked by iraq? a. iran, turkey, united states b. iran, israel, jordan c. iran, kuwait, united states d. iran, saudi arabia, egypt