Explore the "Andesite Problem" and Earth's unique characteristics in this 50-minute Bowen Lecture from the 2012 AGU Fall Meeting. Delve into the bimodal height distribution of Earth's surface, examining the differences between oceanic and continental crusts. Investigate the formation of andesitic continental crust at convergent plate boundaries and the challenges it presents. Analyze the role of mantle convection, plate tectonics, and liquid water in shaping Earth's geology. Examine seismic imaging of the IBM (Izu-Bonin-Mariana) arc system, melting regimes, and the evolution of subduction zones. Consider the factors that make Earth a "shore planet" and how they contribute to its distinctive features. Gain insights into the complex interplay of geological processes that define our planet's unique nature.
The Andesite Problem: Why is This Planet to be the Earth? - Bowen Lecture
Overview
Syllabus
The Andesite Problem: Why is this planet to be the Earth?
The Shore Planet Earth
Continent vs. Ocean
Continental Crust vs. Andesite
Tectonic Evolution of IBM
Seismic imaging of IBM crust/mantle
Characteristic Seismic Structure
Origin of a characteristic middle crust
Melting Regime of IBM Basalt
Volume of Restite/Cummulate after Middle Crust Formation
Arc evolution: creating continental crust and anti-continent
Fate of anti-continent
Subduction zones working as a factory
Chemical modification via dehydration
Isotopic evolution of sediment & MORB
Fate of the anti-continent: isotopic evolution
Subduction Factory
Mantle Convection vs. Plate Tectonics
The presence of water at the surface: the ultimate cause of being the Earth
Taught by
AGU
