Earthquakes

Earthquakes are vibrations caused by earth’s movements at plate boundaries and at major fault lines (cracks in the earth’s surface)

They can occur at all four major plate boundaries but the most severe ones are found at conservative and destructive boundaries

Focus: the point below ground where seismic waves start

Epicentre: the point directly above the focus on earth’s surface where seismic waves spread out from. It is the area that will experience the worst effects

How earthquakes are caused

• Tectonic plates are always moving. If they get stuck, huge pressure can build up

• When plates break free or one plate gives way the energy released causes an earthquake beneath Earth’s surface - at the focus.

• Seismic waves spread out from the focus through the rock and reach the surface at the epicentre

Isoline map: a map where areas with the same value are connected with a line

Tsunamis

Tsunamis are technically just bigger waves, but they are caused by energy originating underwater (e.g. earthquakes, underwater volcanoes) instead of wind, like normal waves.

They can move at speeds of up to 500mph

Ways to protect places include sea walls, channels to divert the water away, early detection & warning systems

When they get closer to shore and into shallow water, they slow down but increase their height, growing up to 100ft tall

→ 20 mins after the earthquake, a tsunami hit the shores of Sulawesi, especially the town of Palu

Sulawesi Impacts & Responses

Impacts

Houses Damaged: would lead to a rise in homelessness and poverty for people who lost their homes. Could lead to rise in disease if people are living out in the open/in poverty/ill

Airports & ports closed: 3 of 9 airports and ports closed, reducing the amount of international aid that can arrive from other places. This means less people can be evacuated.

Responses

Air transport: helps bring international aid, can evacuate people, combats closed ports & airports

Family tents: means people won’t have to sleep/live outside, reduces risk of disease for homeless people

Water purification: reduces risk of water borne diseases, reduces deaths, everyone can have safe water

Medical assistance: will reduce deaths from injury and diseases

Coral reefs

Flora: plants

Fauna: animals

Polyps or corals contain algae which exist with them in a symbiotic relationship - the polyps give the algae a home and the algae give the polyps the food that they generate through photosynthesis.

How to structure 6 mark questions

• Use PDD (point, develop, develop - think ‘so what?’) x2

• Must use specific evidence from the resources e.g. facts & figures (’as seen in figure 3…’)

• If question requires evaluation (command words: assess, evaluate, to what extent, discuss, analyse) make sure to include this - come to an overall conclusion at the end that links back to the question (’overall…’)