The dwarf could see them basking in the sun, brown and black hummocks with jagged ridges down the center of their shells.

侏儒认出它们在阳光下由其背甲中央向下，边缘粗糙的棕黑小丘反射的光。

But the zone is largely treeless, studded with house-size rocky chunks, called hummocks, that broke off the top of the mountain when it exploded.

然而这个区域还是基本上光秃秃的，布满了房子般大小的岩石块，形成一个个的小山岗，这些都是火山喷发的时候从山顶滚落下来的。

The researchers measured the retreat of the permafrost border byobserving hummocks known as "palsas, " which form naturally over icecontained in the soil of northern peat bogs.

研究人员通过观测被称为泥炭丘的小丘来测量永冻带边界北退的程度，泥炭丘是在北部泥炭沼泽含冰的土壤上自然形成的。

In the large image, the area behind the shoreline is pockmarked by marshes, ponds, and hummocks characteristic of "thermokarst," landscapes created by the melting and refreezing of permafrost.

在大图中，海岸线后面的区域由湿地、池塘、热融冰丘形成了凹陷，融化的以及重新冻结的冻土层形成了这种景观。