geography earthquakes junior cert

earthquake

the sudden shaking of the earth caused by the movement of earths crust

seismologist

scientists who study earthquakes

how earthquakes occur

as plates push against each other it creates friction

this causes energy to build up between plates

the plates then slip at a point in the crust called the focus

shockwaves are sent out in circles from the epicentre which is the point on the earths surface directly above the focus. the earthquake is strongest here

focus

the place where an earthquake begins beneath the earths surface

shockwaves

spread out in circles from the focus

epicentre

point at the earths surface thats directly above the focus of the earthquake the strength of the earthquake is greatest here

fault

large crack in the earths crust where plates get stuck and energy build up between them

how a tsunami occurs

an undersea earthquake occurs which disturbs the seabed and causes powerful waves to move out in all directions

the waves become higher as they approach the shallow waters near the coast

a tsunami can destroy low lying coastal areas

seismograph

instrument used to measure and record the magnitude of an earthquake

richter scale

original scale used to measure the magnitude of an earthquake

goes from 1-8

moment magnitude earthquake

replaced the richter scale as its more reliable for larger earthquakes

goes from 1-10

when the nepal earthquake occured

april 2015

nepal earthquake magnitude

7.8

social impacts of the nepal earthquake

9000 died and 17000 injured

electricity water supplies sewage systems and communication systems affected

avalanche occured at mt everest killing 19

economic impact of the nepal earthquake

9b in cost of damage

3.7m people needed emergency aid

1 m children left without schools to attend

short term response to the nepal earthquake

300,000 migrated from kathmandu to seek shelter

red cross provide support eg water food shelter

long term response to the nepal earthquake

earthquake triggered landslides so areas had to be cleared from the material

infrastructure and buildings had to be repaired and rebuilt

no. of countries provided financial aid for long term costs

when the chile earth occured

febuary 2010

magnitude of the chile earthquake

8.8

social impacts of the chile earthquake

over 500 died and 12000 injured

water electricity and communication systems were affected

coastal towns were hit by a tsunami

economic impacts of the chile earthquake

30b cost of damage

tourist industry was hit hard by cancellations

441,000 homes were destroyed or damged

short term responeses to the chile earthquake

the chilean president arranged retailers to provide nessecary items for free for the days after the earthquake

10000 troops were dispatched to help with the recovery

aid was provided by the un

long term responses to the chile earthquake

roads and airports had to be repaired

grants were provided to many who lost their homes

4 months after the earthquake around 50,000 homes had been rebuilt

how to reduce earthquake damage

construction of earthquake safe buildings eg rubber shock absorbers to absorb the shock waves and open areas for emergency evacuation

planning for earthquakes eg not building a hospital in an area with high risk of an earthquake