These are physical models that have been made over the years in order to demonstrate the workings of mid-ocean ridge transform faults.
The first paper model below was handed out to us by J.Tuzo Wilson at my very first scientific meeting. (For a description of that event, click here.)

A second paper (and cardboard box) model is much easier to manipulate. For this, you cut narrow slots into the top of a cardboard box to match the spacing of the folds in the paper strip. Feed the folds down into the slots and pull them down in from the underside. When you pull on the edges, the new "sea floor" will emerge, offset by a transform fault, and the fracture zones will grow in length.

Download: Paper and cardboard transform fault demonstration models. (401 KB)

The third model, made of cloth and wood, is much more elaborate. It is worth building if it will be used in various classes over numerous years. It is a box with an open bottom and slots cut into the top. Cloth ocean floor is then pulled apart, pulling cloth strips out of the slots. The strips are weighted so that they don't pull all the way out and so that, after use, they pull the strips back into the box to reset the geometry. Chuck Anderson designed and built the wooden box version shown below. Click the Download link below and you will get a description of the construction of that box.

Note: You don't need to be a carpenter to make a useable version of this model. My first version used a cardboard box; it held up for several years before it caved in from the weights. Chuck's wooden box version has held up through more than a decade of hard use, though the cloth strips are beginning to fray.

Download: Wood and cloth sea floor spreading demonstration model.

Comments on this and all of the materials offered on this site are welcomed: atwater@geol.ucsb.edu