Outline

Environmental & Geotechnical Geophysics - GPHY 4114

1. What is the field of "environmental geophysics"?
2. Fundamental Ideas

a.

Determining contrasts in physical properties

b.

Simplifying geological descriptions

c.

Defining objectives

d.

Recognizing limitations

e.

Applying multiple methods

f.

Learning from case histories
3. The Seismic Refraction Method

a.

Seismic waves

b.

Elastic properties

c.

Velocities of rocks and soils

d.

Geophones

e.

Seismic sources

f.

Ray paths, Snell's Law

g.

Critical refraction and apparent velocity

h.

Layer velocity and thickness from first-arrivals

i.

Hidden zones

j.

Finding vertical contacts

k.

Designing a refraction survey

l.

Interpretation of first-arrival curves

m.

Case histories
4. The Gravity Method

a.

Fundamental relationships

b.

Measuring gravity

c.

Adjusting observed gravity

d.

Basic field procedures

e.

Gravity effects of simple geometric shapes

f.

Gravity interpretation

g.

Case histories
5. The Magnetic Method

a.

Fundamental relationships

b.

The Earth's magnetic field

c.

Measuring the magnetic field

d.

Basic field procedures

e.

Magnetic effects of simple geometric shapes

f.

Magnetic interpretation

g.

Case histories
6. The Seismic Reflection Method

a.

Reflection, diffraction, and attenuation

b.

Reflection coefficients

c.

The exploration seismograph

d.

Traveltime equation, normal moveout

e.

Layer velocity and thickness from reflections

f.

The optimal window

g.

Multiple reflections, diffractions

h.

The Common Midpoint (CMP) procedure, stacking diagrams

i.

Data processing

j.

Designing a reflection survey

k.

Interpretation of seismic sections

l.

Case histories
7. Electrical Methods

a.

Ohm's Law

b.

Current flow in a homogeneous, isotropic earth

c.

Electrode pairs

d.

Resistivities of geologic materials

e.

Apparent resistivity

f.

Layer thicknesses and resistivity from apparent resistivity

g.

Finding vertical contacts

h.

Electrode surveying configurations

i.

Interpretation of apparent resistivity curves

j.

Case histories
8. Ground-Penetrating Radar

a.

History of GPR development

b.

Instrumentation

c.

Modes of GPR operation

d.

Conduction currents, displacement currents

e.

Electrical conductivity and dielectric constant of geological materials

f.

Refraction, reflection, diffraction of GPR waves

g.

Designing a GPR survey

h.

Data processing

i.

Interpretation of GPR sections

j.

Case histories

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