Every week, The Sassy Scientist answers a question on geodynamics, related topics, academic life, the universe or anything in between with a healthy dose of sarcasm. Do you have a question for The Sassy Scientist? Submit your question here.
Senna asks:
I’m torn between mantle dynamics and lithosphere dynamics as a research topic. Which shall I choose?
Dear Senna,
Could you follow my little Jekyll and Hyde routine over the past two posts, railing about lithosphere dynamics and mantle convection? Some people did not, as my inbox will testify. This is basically what it has been over the past few decades. Let’s be clear: we don’t live in the 70’s anymore. We’re capable of more subtlety and have to live in the in-between: the world is full of grey tones (yes, also shades of grey).
Numerical modelling of mantle convection systems that includes oceanic and continental lithosphere has greatly improved. Producing tessellation of the Earth’s surface and long-term supercontinent cycles in combination with realistic surface kinematics is a big step forward. Does this mean we completely understand the solid Earth system? Definitely not. Do mantle convection modellers have to realise that the relative importance of the mantle on surface kinematics may only be a transient feature on a regional scale, and that surface motions may be unrelated to mantle flow? Maybe. Do lithosphere dynamics modellers have to realise that the relative importance of the mantle on surface kinematics may only be a transient feature on a regional scale, and that this doesn’t mean that the mantle definitely always or never influences surface motion? Maybe. Does everybody involved need to realise that their idea of the truth may not be the whole truth? Definitely. Is there a place for both lines of inquiry into understanding the solid Earth system? Undoubtedly.
I’ll come back to your question. There is no mutual exclusivity between mantle convection and lithosphere dynamics. It’s all part of the same system. So whatever you choose, just realise this: do not blindly step into the mantle convection gateway or lithosphere dynamics portal to the maze of solid Earth dynamics and kinematics. Both alleyways will probably end up in the same central square of enlightenment.
Yours truly,
The Sassy Scientist
PS: This post was written after getting hammered repeatedly by the Editor-in-Chief over my previous two posts.
