Environmental Geology lecture outline
- Earthquake prediction
A successful prediction vs. a successful
The interesting case history of the Jupiter
effect, Iben Browning and the 1990 prediction.
Components/types of predictions:
- as to future location of earthquakes.
- maximum magnitude earthquake for an area.
- recurrence interval for a given size EQ
for an area.
- prediction of location, size, and time
frame of earthquake.
Future location and size of earthquakes
(neglecting time component):
- plate setting, historical record, microseismicity.
- Meers fault in Oklahoma.
- identification of active faults by geomorphic
signature and trenching (e.g. Kerry Sieh, Pallett
Creek and the San Andreas).
- paleoseismic indicators (liquefaction
features and tsunami deposits, e.g. W Washington).
- seismic gaps and locking geometries.
Estimation of recurrence interval:
- Gutenburg-Richter log-log frequency-size
- fractals and fracturing.
- 40% chance of great EQ in southern CA
in next 30 years.
- extending the record with trenching.
- for intraplate EQs.
- use of these estimates for building codes.
Prediction based on dilatancy hardening
theory and the use of precursors.
- dilatancy in the laboratory.
- expression as precursors in the field:
foreshocks, surface bulges, changes in water level, changes in
seismic velocity, changes in radon content of water, localized
changes in earths magnetic field.
- Haicheng, NE China prediction in 1976
of 7.3 RM EQ, 10% success rate claimed in China.
- overall success questionable?
Cost of a precursor monitoring program?
H.D. Maher Jr., 3/2/98
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