n. (如极地的)永久冻土;多年冻土
网络 永冻层; 永久冻土; 永冻土
Their roots don´t grow very deep, so the permafrost doesn´t interfere with their growth.
它们的根长得不深,所以永久冻土不会影响它们的生长。
Beneath this active layer is a second layer called "permafrost", which is frozen all year around, and is impermeable to water.
在这一活跃层下面,是被称为“多年冻土”的第二层,终年冻结,不透水。
There´re two reasons for this: first, they live in the active layer, which, remember, contains water that doesn´t penetrate the permafrost.
造成这种情况的原因有两个:首先,它们生活在活动层中,请记住,活动层中包含的水不会渗透永久冻土。
Geologists think that this fluidized ejecta crater indicates that a layer of permafrost, or water ice, lies just a few meters under the surface.
地质学家认为,这个具有流体化喷出物的陨石坑表明,在地表下几米深处有一层永久冻土层或水冰。
The answer may be that virtually all the water on Mars is now locked in the permafrost layer under the surface, with more contained in the planet´s polar caps.
答案可能是,现在火星上几乎所有的水都被锁在地表下的永久冻土层中,更多的水被包含在这个星球的极地冰帽中。