Geophysics

The reflection coefficient is determined by the differences in acoustic impedance, which is a product of density and velocity

Island arcs form where one oceanic plate subducts beneath another, causing volcanic activity along the boundary.

Seismic tomography uses variations in seismic wave velocities to create images of Earth’s internal structure, such as mantle plumes and subducting slabs.

Resistivity surveys measure the resistance of subsurface materials to electrical current flow, useful for detecting water, minerals, and faults.

Magnetic stripes on the ocean floor, caused by periodic geomagnetic reversals, provide direct evidence of sea-floor spreading and plate tectonics.

The Moho marks the boundary between the crust and mantle, typically at greater depths beneath continental crust compared to oceanic crust.

Refracted waves occur due to a change in seismic velocity across layer boundaries following Snell’s Law.

Negative anomalies suggest regions with lower-density structures, such as sedimentary basins or thick continental crust.

The motion of liquid iron and nickel in the outer core creates electric currents that generate Earth’s magnetic field via the dynamo effect.

P-waves are compressional waves that can propagate through solids, liquids, and gases, while S-waves cannot travel through liquids.