Hi all, there was just a M6.4 earthquake near the equator, near the Mid Atlantic Ridge. It plots on a transform fault that connects offset spreading segments. Tuzo Wilson, who is dead, in a famous paper in 1965 predicted that for a left offset of a spreading center (actually, a left "step"), you would expect right-lateral strike-slip earthquakes. A couple years after, Lynn Sykes, who still works at Lamont, calculated focal mechanisms of earthquakes that showed the prediction was right-it was an important test of plate tectonics. Earthquakes have "focal mechanisms" that can be calculated that show the slip plane and the plane that is perpendicular to the slip plane. Unless you have other information, like a linear trend of aftershocks, it is hard to tell which plane is the correct one. In the case today, the ENE-WSW plane parallel to the mapped transform is right-lateral as predicted.

Speaking of the 60s and plate tectonics, I was taught in elementary school that the earth was shrinking like an apple, causing mountains. In the 1980s, I was told that it was still widely thought in the soviet union that spreading centers existed, but subduction did not, so the earth is expanding. I'm not sure where the extra material was supposed to be coming from. Anyway, its a good idea to look at ideas and not believe them-show a little discretion. Hint Hint. In fact, maybe I made up everything in this post. Or, maybe it is all true. Its to you to figure out what is true in this post.
1: There was a 6.4 EQ Dec 21 2003(T/F)
2: The ENE-WSW nodal plane is right-lateral.
3: Tuzo Wilson published on transform faults.
4: Mountains are formed because the earth is shrinking like an apple.
5: I was told in elementary school that mountains are formed because the earth is shrinking like an apple.
6: The earth is expanding.
7: I heard a famous soviet scientist say that the earth was expanding.
8: I was told second-hand by a French graduate student that she had been taught that the earth was expanding by a Soviet scientist.
9: It has been conclusively demonstrated on this page that solar flares trigger earthquakes, and we should all accept this as fact and just move on to stating that as a starting point.
etc.
Chris

• transform earthquake