Earth’s core composition
Earth’s core is mostly iron and nickel, but these alone do not explain its measured properties. Which lighter elements are mixed in, and how are they distributed?
Earth’s interior
Structure, water and rock chemistry, magnetic-field power, and seismic signals from deep inside Earth.
Subjects: Earth science
Problems in this collection
8 problemsLarge low shear velocity provinces
Two enormous regions near the bottom of Earth’s mantle slow seismic waves. What mixtures of heat and material create them, and how have they changed through time?
Early geodynamo energy budget
What supplied the energy to sustain Earth’s magnetic dynamo before the solid inner core grew?
Deep mantle water cycle
How much water do subducting rocks carry deep into the mantle, and how is it exchanged?
Deep-focus earthquake mechanism
How do earthquakes occur hundreds of kilometres down, where ordinary brittle failure is suppressed?
Inner-core seismic anisotropy
Seismic waves travel through Earth’s inner core at different speeds in different directions. What produces the pattern and its changes with depth?
Deep long-period volcanic earthquakes
What produces unusual low-frequency seismic signals deep beneath volcanoes?
Hydrogen generation by serpentinization
How quickly do water and iron-bearing mantle rocks generate hydrogen underground?