Earthquakes and Society

1. Earthquakes and Society Chapter 8 Section 3

2. Earthquake Hazard • A measurement of how likely an area is to have damaging earthquakes in the future • Determined by past and present seismic activity

3. Strength & Frequency • Strength of earthquakes is related to how often the occur

4. Gap Hypothesis • Based on the idea that sections of active faults that have had relatively few earthquakes are likely to be the sites of strong earthquakes in the future Seismic gaps • Areas along a fault where relatively few earthquakes have occurred recently, but where strong earthquakes have occurred in the past

5. 5 Ways to Safeguard Buildings • Mass damper -weight placed in the roof to counteract the building’s movement • Cross braces –placed between floors to counteract pressure that pushes and pulls at the sides • Active tension system – like mass damper only in the basement • Base isolators – acts as a shock absorber • Flexible pipes – prevent waterlines and gas lines from breaking

6. Earthquake Safety