Final answer:
The understanding of the Earth's crust and upper mantle has improved significantly in recent decades through advancements in Geography.
Step-by-step explanation:
The subject of this question is Geography and the grade level is High School.In the last few decades, our understanding of the Earth's crust and upper mantle has significantly improved. We now know that the Earth's crust and upper mantle are divided into tectonic plates, which fit together like puzzle pieces. These plates are constantly moving due to the slow convection of the mantle, where heat escapes from the interior through the flow of warmer and cooler material.This improved understanding has led to advancements in topographic mapping science and the ability to analyze the chemistry of upper mantle material through samples ejected from volcanoes.