The type of stress that pulls on and thins an area of Earthis crust is called*

The type of stress you're referring to is known as "tensional stress." This interesting aspect of geology causes the crust to stretch and thin, often resulting in the formation of rift valleys or mid-ocean ridges. It's like a cosmic game of tug-of-war, where the Earth's plates are pulling away from each other, leading to fascinating geological formations! In real-world applications, understanding tensional stress is crucial for predicting geological events such as earthquakes and volcanic activities. Engineers also take this knowledge into account when designing structures near tectonic plate boundaries. By appreciating these stresses, we can build safer buildings and ultimately protect communities from the unpredictable whims of our restless planet!