esker
/ˈɛskər/
noun
- A long, narrow, winding ridge of sand and gravel, formed by a stream flowing under a glacier.
- Geologists studied the esker to learn about the direction of ancient glacial meltwater.
- Farmers often use the well-drained soil of an esker for growing crops.
- The hikers followed the esker across the flat valley, noticing its steep sides.