2nd Year: Geophysical Methods in Geology

Trinity Term 2006

Week 4:

Fri. 10-11 Lecture 1 : Seismic refraction

Instruments and survey design. Travel-time distance graphs. Interpretation of layer thickness and velocities. Dipping layers, hidden layers, time term method.

Week 5:

Tues. 10-11 Lecture 2 : Seismic reflection

Instruments and survey design. Shot gathers and Common Depth Point (CDP) stacks. Velocity analysis. Normal Moveout. Multiples.

Powerpoint slides

Fri. 10-11 Lecture 3 : Electrical methods

The resistivity of rocks. Electrode arrays and apparent resistivity. Resistivity data interpretation. Pseudo-sections. Self potential (SP).

Fri. 11-1 Practical :

Reflection seismic data processing

Week 6:

Fri. 10-11 Lecture 4 : Electrical methods

Induced polarisation (IP). Time and frequency domain IP methods. Basic principles of electromagnetic prospecting. Tilt-angle, phase and VLF methods.

Fri. 11-1 :

Mendips geophysical data processing and reduction

Week 7:

Fri. 10-1

Mendips geophysical data processing and reduction

Mendips field data

Seismic data:

NOTE: Sample interval = 0.000125 secs

When looking at the .xls files, remember that if there is a 0.02 sec pre-trigger

before shot time zero, time zero sample number = 0.02/0.000125 = 160.

So travel time from the .xls file = (sample number - 160) * 0.000125 secs

Seismic lines shown on the map Location of seismic lines

are as follows:

A Thursday morning

B Thursday afternoon and Friday morning

C Saturday and Sunday

2nd Year: Geophysical Methods in Geology Trinity Term 2006