The essential feature is differential movement parallel to the plane of the fracture. Let's get closer and use the compass to measure the attitude of that inclined plane.

断层最基本的特征就是平行破裂面有差异运动的产生。我们走近些，然后用罗盘测量一下那个倾斜的断面的产状。

youdao

Suppose you decide to make a trek to the North Pole. You can't catch a plane there. So instead, you pull out your compass, watch the needle swing northward and plot a path, right?

假设你决定长途跋涉去北极，又不能坐飞机去，那么只好拿出指南针，根据指向北方的指针绘制出路径，对么？

youdao

Rick: I know. It's OK. With this kind of compass, we'll be able to make our way back to the plane if we get lost inside this big old ship and can't find our way out.

我知道啦。用这种指南针的话，即使我们在这巨大而又古老的飞船里迷了路，我们也能找到回飞机的路。

youdao