STAG6314

What is the primary difference between seismic refraction and seismic reflection surveys?

• Refraction uses only P-waves, while reflection uses S-waves.

• Refraction measures waves that bend at interfaces, while reflection measures waves that bounce off interfaces.

• Refraction works in soft sediments only, while reflection works in hard rocks only.

• Refraction is used for deeper subsurface exploration, while reflection is used for shallow investigations.

Which physical property is most crucial in determining seismic wave velocity in subsurface materials?

• Temperature

• Elastic modulus

• Porosity

• Density

In near-surface geophysics, which of the following methods is commonly used to measure the Earth's gravitational field?

• Gravimetry

• Magnetometry

• Seismology

• Resistivity

Which of the following waves travels fastest through the Earth's subsurface?

• Rayleigh waves

• S-waves (Shear waves)

• P-waves (Primary waves)

• Love waves

In a near-surface geophysical survey, an anomaly in a magnetic field is most likely associated with:

• Changes in moisture content

• Variations in subsurface density

• Presence of ferromagnetic materials

• Subsurface electrical conductivity

Which principle explains the bending of seismic waves as they pass through materials with different velocities?

• Snell's Law

• Coulomb's Law

• Hooke's Law

• Newton's Second Law

In Electrical Resistivity surveys, which of the following factors would lead to a decrease in measured resistivity?

• High porosity and saturated materials

• Low moisture content

• Highly compacted dry soils

• Increased temperature of the subsurface

Which of the following is true about Rayleigh waves in near-surface geophysics?

• They are compressional waves that travel through the Earth's interior.

• They are surface waves that cause both vertical and horizontal ground motion.

• They travel faster than P-waves and S-waves.

• They are commonly used to measure magnetic anomalies.

What is the primary purpose of performing a gravity survey in near-surface geophysics?

• To detect seismic wave arrivals

• To map subsurface density variations

• To determine groundwater levels

• To measure subsurface resistivity

Which of the following instruments is used to measure the Earth's magnetic field in near-surface geophysics?

• Gravimeter

• Magnetometer

• Seismometer

• Resistivity meter