Re: What are ocean waves called 'graybeards'?

Hi Mike-

I had a look around, and while there isn't a lot in the oceanographic literature on "greybeards", and all the physical oceanographers I talked to hadn't heard of them, I think I can tell you a bit about them:

Greybeards, also known as "Cape Horn rollers" are, like you said, generally found in the Southern Ocean, which spans all the way around the globe in the southern hemisphere, from about 40S down to Antarctica. I've included a picture of the world ocean that shows how the Southern Ocean spans the globe.

As you may know, the Southern Ocean lies within a zone of winds known as the westerlies, that blow across the entire Southern Ocean from west to east. The winds in that zone can be extremely strong, and mariners often refer to it as "the roaring forties", with good reason. Now, if there's one thing that wind is good for, it's making waves; and the longer the winds blow, and the longer the distance they blow over (known as "fetch"), the larger the waves will be. As you can see from the above picture, the winds in the Southern Ocean have more fetch than anywhere else in the oceans, which means the waves can get to be very big. It doesn't require a big storm to create those big waves, just a steady wind over a long fetch.

Hope that answers your question!
Rob Campbell, MAD Scientist