1. HAZARDS Seismic hazards
The nature of seismicity and its relation to plate tectonics

2. Seismicity
Seismology is the study of earthquakes and the elastic properties of the Earth
Seismicity refers to the intensity and frequency of earthquakes in an area
Seismic waves are earthquake shock waves generated from the earthquake focus within the earth’s crust
A seismometer (or seismograph) is a scientific instrument which records seismic waves
A seismogram is the record of an earthquake produced by a seismograph - shows the magnitude, frequency and duration of the seismic waves produced by an earthquake

4. Seismicity by numbers 9.5 9.0 24km 40.4m 10km 1 minute 20,000
$300 billion
3.8
8km

5. Seismicity by numbers
9.5 biggest earthquake recorded in 20th century Chile 1960
9.0 magnitude of earthquake Tohoku Japan 2011
24km depth of earthquake focus Tohoku Japan 2011
40.4m maximum height of tsunami Tohoku Japan 2011
10km furthest distance inland reached by tsunami Tohoku Japan 2011
1 minute warning time for Tokyo from earthquake warning system Tohoku Japan 2011
20,000 estimated people lost (dead and missing) Tohoku Japan 2011
$300 billion estimated cost of damage earthquake Tohoku Japan 2011
3.8 magnitude of Oakham earthquake Oakham Rutland, UK January 2015
8km depth of Oakham earthquake Oakham Rutland, UK January 2015

7. Global distribution of earthquakes

8. Global distribution of earthquakes
red = shallow focus 0-70km green = intermediate focus km blue/purple = deep focus km