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How did thermal expansion help form the East African Highlands?

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plateau The Columbia Plateau is uniformly covered with basaltic lava flows and spans an area of about 100,000 square miles in Idaho, Washington, and Oregon.

The East African Highlands were formed through the process of thermal expansion, a tectonic mechanism that occurs when the lithosphere underlying a broad area is heated rapidly.1

This heating is typically caused by the upwelling of hot material from the underlying asthenosphere. As the uppermost mantle warms, it undergoes thermal expansion, which generates an uplift of the surface above it. Because the surface in this region was originally low and lacked prominent relief, this rapid heating and subsequent expansion lifted the land to a relatively uniform, high elevation, creating the extensive plateaus characteristic of East Africa and Ethiopia.1

While this uplift is often associated with volcanism and the development of rift valleys, these features are not required for the formation of such plateaus; for instance, much of the high plateau surrounding Lake Victoria lacks volcanic rock and is only minimally affected by rifting.1