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CH 4 Earthquakes - Coggle Diagram
CH 4 Earthquakes
Earthquake proof buildings
Rubber shock absorbers between foundations + building above
Steel foundations in the bedrock
Steel cage to stabilize buildings
Safe open areas for people to gather
ID number for helicopters to identify buildings
Reinforced lifts with tensioned cables
Shutters that come down automatically
Waves + Measuring
Waves
Body waves : Primary
are fast and travel through molten interior of earth. They compress and expand material causing back and forth vibrations.
Secondary
are slow and move through solid rock. They vibrate at right angles.
Surface
: Slowest type. They travel along surface cause up and down movements and side to side. Devastating and most destructive.
Measuring
1 .Seismometer
Seismograph
Richter Scale- Magnitude
Mercalli Scale - Intensity + Observations
Effects + How to limit them
Effects
Primary
: Death, destruction, flooding, mudflow, homelessness, fires.
Secondary
: Tsunami, diseases, homelessness, unemployment, migration, increased crime rates.
How to limit
Early warning systems
Improved construction standards
Awareness programmes
Formation + Types
Formation
- Plates are constantly moving, they sometimes stick together and puts the rock under stress. A build up of energy is stored in rocks. When stress is too much plates slip and energy is released causing earthquakes.
Types
Shallow
- Occurs when focus close to surface, more common than deep earthquakes. Associated with plate boundaries. Cause most damage on surface and produce stronger tremors.
Deep
- Focus greater than 300km up to 700km deep. Associated with subduction zones. Rarely cause damage on surface because energy is lost before it reaches surface.
Scales + Forecasting
Scale
Richter Scale
- Measures magnitude, each unit increase represents a 10 fold increase. Goes up to 10. less than 3.5 not felt but recorded, 6.0 major damage to buildings, 8.0+ can cause serious damage in areas over several hundreds of km.
Mercalli Scale
- Measures intensity of earthquake and is based on peoples observations. It ranges from 1-12. 1-2 people don't feel movement. 5-6 hard to walk, objects fall, plaster on walls crack. 11-12 almost everything is destroyed, ground moves.
Forecasting
looking at patterns of seismic activity. Seismic gaps. Early warning systems detect and signal immediate warning. Animal behavior.