Modified Mercalli Intensity Scale (MMI): describes intensity of earthquake using observed effects at 12 different levels.

Elastic Rebind Theory: earthquakes are the result of the sudden release of energy stored as a result of rock deformation.

Much like a squeezed stress ball, the deformed rock “rebounds” to its original position releasing energy.

Earthquake Induced Natural Disasters: 1. Tsunami 2. Landslides.

Tsunami: seismic sea wave caused by the displacement of water Tsunami: seismic sea wave caused by the displacement of water. Causes: EQ, Volcanoes, Asteroids, Comets

Most Tsunamis are caused by EQ Most Tsunamis are caused by EQ. When the sea floor rebounds at a plate boundary it displaces a large mass of water instantly.

Landslide: the movement of earth and rock down a slope Landslide: the movement of earth and rock down a slope. Triggered by EQs, Volcanoes, human land modifications.

Six LS types: 1. Slide 2. Creep 3. Slump 4. Topple 5. Fall 6. Flow Six LS types: 1. Slide 2. Creep 3. Slump 4. Topple 5. Fall 6. Flow. A more in-depth lesson will follow.

EQs, tsunamis, and landslides occur suddenly and with little or no warning so preparation is key to casualty prevention.

LEDC generally show poor preparation, construction and infrastructure LEDC generally show poor preparation, construction and infrastructure. Every $1 spent, returns $5 in loss prevention.

LEDC are less likely to make the investment in preparedness due to lower GDP/GNP.

LEDC mortality rate is significantly higher LEDC mortality rate is significantly higher. MEDC have reduced mortality from EQs at a rate 10x faster than LEDC.

LEDC economic loss is more likely to exceed GDP of country.

LEDC recover more slowly from EQ damage.

MEDC invest more money into EQ-resistant structures.

Cross-Bracing transfers existing support of floor to the ceiling above Cross-Bracing transfers existing support of floor to the ceiling above. Similar to pillars but CB is within walls.

Base-isolation: floating a building above its foundation using springs or bearings. Stabilizes building position while the foundation moves during EQ.

Shear walls facilitate resistance to horizontal forces by carrying EQ loads to the ground.