The Evolution of Terrestrial Planets: Insights from Models of Planetary Evolution with Coupled Internal, Atmospheric/Surface Development

ended

It is critical to integrate knowledge from multiple disciplines in order to gain a better understanding of the Earth and other terrestrial planets evolution, as well as the effects of this evolution on the expression of surface tectonics. While plate tectonics is currently observed on Earth, both its onset and length of activity are uncertain. Here we will use models of planetary evolution to begin to understand the implications for coupled internal/surface processes through changing lid states over planetary timescales (e.g. C, H2O, and O2, cycles, generation of atmosphere, dynamo generation, and coupled lithosphere-asthenosphere evolution). Further, the internal chemical composition, heterogeneities, and initial conditions within the mantle may be critical factors in setting the evolutionary path of a planet, as such we will determine what role these heterogeneities may play in the evolution of the planet. Finally we seek to understand the controls on the dynamics of a transitional episodic-lid, a state suggested for the early Earth, such as its onset, duration, recurrence interval, and location of overturns, and use these results to assess the implications for planetary development (e.g. dynamo heat flow, generation of atmosphere). This work will begin to address the following open questions: (A) What role does the coupling of internal and surface processes have through changing lid-states? (B) What role do heterogeneities (in viscosity, radiogenics and composition) play in the evolution of the planet? (C) What controls the dynamics of the enigmatic transitional episodic-lid?