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Hi there! I am a recent graduate with an Earth and Space sciences degree and my current work is in assessment development. I am writing to inquire about current teachers understanding of the mechanism of plate movement. For years and year, convection has been the basic description to explain plate motion. I was even taught that in high school. My professors all will agree that ridge push and slab pull (gravity-related phenomena) are the more likely drivers of this process. From what I gather, convection plays far less of a role--if any. However! The framework for K-12 Sci. Ed. still has understanding convection as the primary HS gradeband expectation for plate tectonics. I plan to do a lot more research, just want to get some thoughts from educators out there. Thanks! :)

Hi Kristine, It is an interesting point you raise and I guess reflects the fact that the experts who put together the new standards were either not aware of the new consensus or decided to wait until the revised theory has been more rigorously formalized. As a former geologist, I had heard about the push-pull theory back in my university days (along with the expanding Earth hypothesis) but in recent years had not heard or read anything about the general shift in favor of this mechanism over convection. I just checked Science Daily which is a site some teachers here use and did find an article from 2010 that discusses a new mechanism although surprisingly, no mention of slab pull is made. But this indicates that the revised theory is still relatively new so it may take until the next revision of the standards before we see a change in the curriculum. But now that teachers at this site have seen your post, hopefully they will also discuss the ridge-push, slab-pull mechanism with their students.

Hi Kristine, It is an interesting point you raise and I guess reflects the fact that the experts who put together the new standards were either not aware of the new consensus or decided to wait until the revised theory has been more rigorously formalized. As a former geologist, I had heard about the push-pull theory back in my university days (along with the expanding Earth hypothesis) but in recent years had not heard or read anything about the general shift in favor of this mechanism over convection. I just checked Science Daily which is a site some teachers here use and did find an article from 2010 that discusses a new mechanism although surprisingly, no mention of slab pull is made. But this indicates that the revised theory is still relatively new so it may take until the next revision of the standards before we see a change in the curriculum. But now that teachers at this site have seen your post, hopefully they will also discuss the ridge-push, slab-pull mechanism with their students.

Apologies for the multiple posts!!

According to recent Prentice Hall Tarbuck and Lutgens Earth Science text, slab-pull is thought to be a part of the downward arm of convection. I would think that convective heat loss is still the main driving force of tectonics, and is what I teach in my high school classes.

Hello, In our curriculum we definitely focus on convection when discussing plate movement. If there is new information out there which could correct an older preconceived notion than I would be all for shaking up our standards. Please post when you have conclusive evidence as to a change in any evidence to refute the convection theory, I'd love to introduce it to my students.