The P-wave shadow zone is largely the result of ________.
refraction of P waves crossing the mantle-outer core boundary
The Earth's magnetic field originates by ________.
weak electrical currents associated with fluid motions in the outer core
The Earth's magnetic field ________.
is a self-generating and self-reversing dynamo in the outer core
Which of the following best characterizes how the diameter of Earth's core and the nature of the outer core were discovered?
by analysis of the P-wave and S-wave shadow zones
The fact that ________ is good evidence for a solidified, inner core.
P waves are faster in the inner core than in the outer core
Dense forms of ________ are probably major components of the inner core.
crystalline iron and nickel
The ________ is the seismic discontinuity that forms the boundary between the crust and mantle.
The ________ of the Earth is enriched in the elements silicon, potassium, sodium, and aluminum compared to the most common types of stony meteorites.