Daily Archives: February 27, 2015

drumlin

Does this word resonate with you? Does it have a hollow sound, a soft echo, or a rumbling? Does it seem to have a shape? It has that drum, of course, which is impossible to ignore. And it makes me think of hard things tumbling in the drum of my clothes dryer. On the other hand, to the eyes it might suggest a drum line, a long thin rank of people in a drum corps. Or you could just assume that it has an arbitrary association between sound and sense and leave it at that. (But what’s the fun in not even tasting the sound of it?)

You may recognize this word. If you don’t know just what it’s a name for, you may still remember it from high school geography. Something to do with glaciers? Didn’t I just blog about glacial stuff yesterday and the day before? Right, this must be something like… uh… It’s not a moulin, is it? Or maybe more like a monadnock or nunatak or…

Imagine a heap of gravel and dirt. Imagine it in the middle of a stream. Imagine the stream flowing around it, so that the heap turns into something of an oval or teardrop shape, almost reminiscent of a cross-section of an airplane wing (or perhaps a mandolin). Now imagine that the stream is a glacier. And that the heap is about 30 metres (100 feet) high, and the glacier is all gone now.

That’s a drumlin: an oblong hill that demonstrates that aerodynamics, hydrodynamics, and glacier dynamics have some things in common. You can tell which way the glacier was flowing because the drumlin’s downslope is long and gradual in that direction, and steep and short on the upstream side.

They can be found in many parts of the world, not just near glaciers. After all, much of the world was covered with glaciers at one time (and I don’t mean last Tuesday, however it may have felt). They’re all over the place in eastern North America – it wouldn’t take me too long to drive to one. They tend to appear in clusters. Whether you’re in Berlin or Dublin, you’re not too far from a drumlin.

And if you’re in Dublin, you’re around where they got their name. Yes, like esker, this word comes from an Irish word. Irish Gaelic for ‘ridge’ is druim (pronounced like something between “drim” and “thrim”). That got a diminutive suffix, as either English drumling or Irish droimnín (droim and druim are pronounced the same), and from that we ended up with drumlin. I wouldn’t say phonological changes are glacial, whether by effort conservation or by analogy, but they do have their effect on the shape of a word.

So the word has an arbitrary association between sound and sense, originally. It didn’t come from a rumbling of tumbling boulders and sediment. But tell me now you can think of a drumlin without thinking of it in some vague way as having a drum shape.

Thanks to Laurie Miller for suggesting today’s word.