Key Question=What are plate boundaries and the resulting hazards? By the end of the lesson you will need to be able to:- Name and the describe the layers of the earth Describe what a plate boundary is and how they move around on the mantle. Identify the 2 types of crust and describe their characteristics Tectonic Hazards

Starter activity-what do you already know about the structure of the earth? What are tectonic plates?

Plate tectonics The map below shows a map of the plate boundaries (where 2 plate boundaries meet). The arrows show the direction of the plate movement and give an indication as to the type of plate boundary.

Plate movement 1_L3fA How do the earth’s tectonic plates move? The Earth's crust is broken up into pieces called plates. Heat rising and falling inside the mantle creates convection currents. The convection currents move the plates around on the mantle.

Types of crust – oceanic and continental Oceanic crust: As the name already suggests, this crust is below the oceans. There, the crust is 4-7 miles (6-11 km) thick. The rocks of the oceanic crust are very young compared with the rocks of the continental crust. The rocks of the oceanic crust are not older than 200 million years. Continental crust The earth's crust is the thickest below the continents, with an average of about 20 to 25 miles (30 to 40 km) and with a maximum of 45 miles (70 km). The continental crust is older than the oceanic crust, some rocks are 3.8 billion years old. The continental crust mainly consists of igneous rocks

Plate Boundaries 1). Constructive plate boundaries Here the land is moving apart It constructs new crust, e.g. Mid Atlantic Ridge You may get earthquakes as friction is caused as they move over the mantle. There is lots of volcanic activity from fissures e.g. Iceland. 2). Destructive subduction plate boundary Here oceanic and continental crust is moving together. The oceanic crust is denser (heavier) and therefore sinks (subducts) underneath the continental crust. This friction causes earthquakes. The land on the edge of the continental plate gets squashed up and makes FOLD MOUNTAINS e.g. the Andes. The oceanic crust melts as it is forced under the continental crust. Once under it is still lighter than the mantle it has entered. It rises up through weaknesses in the crust and reaches the surface explosively as a volcano

Constructive boundary Here the plates move apart, magma moves up from the mantle below and makes new land Landform = mid-ocean ridge (Atlantic)

Destructive boundary Here the plates move towards each other. Oceanic crust is more dense and is forced down (subducted) beneath the lighter continental crust. It melts into the mantle Landform = Ocean Trench Landform = Volcano

Plate Boundaries 3). Conservative/transform plate boundaries Here the plates are moving past each other. There are many earthquakes along these margins as friction builds up There are no volcanoes on a conservative plate boundary. E.g, San Andreas Fault in California (North American Plate & Pacific Plate) 4). Destructive/Collision Zones Here 2 continental plates are pushing into each other. They weigh the same so neither of them sinks and they squash upwards to make FOLD MOUNTAINS, e.g. Himalayas. There are strong earthquakes at these margins because of the huge pressures created. CASE STUDY – Living in a collision zone – Pg12 & 13 – Himalayas (farming; mining; Tourism & living with danger)

No landforms occur here but lots of earthquakes happen

Destructive collision zone Here the plates move together. As they are both continental they weight the same and force each other to fold upwards creating fold mountain ranges. Landform = Fold Mountain

Plenary-True or False-Whiteboard Work 1.A plate boundary is where 2 plates meet. 2.The earth’s crust sits on the outer core. 3.The mantle is liquid rock. 4.There are 5 types of plate boundary. 5.An example of a constructive plate margin is the Eurasian and North American plates. 6.Convection currents move the plates around. 7.Conservative plate margins form new land. 8.There are 3 types of crust. 9.Destructive collision zones happen when the 2 pieces of crust are different densities. 10.Ocean trenches form at subduction zones.

Plenary-True or False-Whiteboard Work 1.A plate boundary is where 2 plates meet. 2.The earth’s crust sits on the outer core. 3.The mantle is liquid rock. 4.There are 5 types of plate boundary. 5.An example of a constructive plate margin is the Eurasian and North American plates. 6.Convection currents move the plates around. 7.Conservative plate margins form new land. 8.There are 3 types of crust. 9.Destructive collision zones happen when the 2 pieces of crust are different densities. 10.Ocean trenches form at subduction zones. Now correct the inaccuracies in the red ones…….What should they say?

Homework -CGP Exam practice work booklet Pg3 Tectonic Plates

Plate boundaries A plate boundary is. Plates are made from the earth’s crust. There are 2 different types of crust. The table below shows the types and their characteristics…. There are 3 types of plate boundary………. 1). Destructive-subductionA global example is

1). Destructive-collisionA global example is 2). ConstructiveA global example is 3). ConservativeA global example is

Plate boundaries Type of plate Destructive subduction Destructive Collision ConservativeConstructive Direction of movement Towards each other and then forced down Type of crust Oceanic forced under continental Global example Nazca Plate under the South American Plate Hazard/ landform Ocean Trench Fold Mountain Volcano Earthquake.