Earthquake Seismology

Lars Ottemöller

University of Bergen, Norway

Earthquakes• What are they?• Where do they occur?• When do they destroy?• What do we learn from them?• How are they measured?

Seismology

Study of :• Earthquakes• Elastic wave propagation

Results are:• Images and Dynamics of Earth interior • Basic understanding of the earthquake process

Applications:• Academic, Seismic hazard, hydrocarbon production,

nuclear explosion monitoring, ...

•Analogy to sound and light: reflection, refraction, diffraction

•P, S and surface waves

Seismic monitoring

(Linton and Stein, SRL 2012)

Earthquake simulation

Elastic rebound model

Fault geometry Plate tectonis

Loma Prieta 1989 (Wald et al, 1991)

Northridge 1994 (Dreger, 1995)

Prediction – Forecast

Earthquake cycle

Earthquake hazard

Secondary Hazards

• Landslides• Tsunamis• Soil liquefaction• Fire

Concluding remarks on earthquake monitoring• important in regions of low and moderate

seismicity to understand the hazard• requires long term commitment• high quality monitoring required to understand

the earthquake source • results: earthquake distribution, earthquake

source processes, stress pattern, earth structure, local site effects, ...