Unit 10

Unit 10. Page 31

Q. 26.Page 13…………………………………………

Q. 35 Q. 33 Seismic belts are located: Unit 9. Page 16 Q. 33 Seismic belts are located: At ocean ridges and next to ocean trenchs and young mountain ranges. Q. 35

Page 17. Question 38

What is a subduction zone?

Consolidation Page 24 78. What is subduction and where does it happen? Subduction is the process in which the oceanic lithosphere moves under the continental lithosphere (or oceanic lithosphere in the case of island arcs) and into the mantle. It happens at ocean trenches. 79. The Mid-Atlantic Ridge passes through Iceland. What will happen to the island with the passage of time? Iceland will eventually rift apart as the divergent plates beneath it will split

Consolidation. Page 46

Unit 10. Study skills. Page 47

Consolidation. Page 46

Page 37……Question 24

……………………. Page 46 Horizontal fault

Page 46. The deformation of rocks Question 56 What kind of force do we use when we chew gum? And when we blow up a balloon? When we chew gum, compressional stress, and when we blow up a balloon, tensional stress.

continental-continental collision tend to have a little of everything: Earthquakes, few volcanoes,folds, normal faults *

The formation of mountains between India and Tibet

Andean orogeny

ANDES: classic example of marginal mountain range“cordillera” View from Nev. Pisco, Cordillera Blanca NASA satellite image *

Oceanic-continental plate

Japan

Methods for studying the Earth´s interior. Page 8

Seismic method

11. Look at the graph and answer the questions. a) What does this graph show? The graph shows the speed and the depth at which P and S waves travel. b) Which waves are moving faster, the S or P waves? Why? P waves. We know this because they are represented above S waves on the graph.

c) How many seismic discontinuities can we see on the graph c) How many seismic discontinuities can we see on the graph? What is their depth? We can see two discontinuities on the graph: the Moho discontinuity after a few kms and the Gutenberg discontinuity after 2 900 km. d) According to the graph, how many layers are there in the Earth’s interior? Three: the mantle, the inner core and the outer core.

Consolidation Page 24. Q.71 Why did scientists find much less marine sediment on the ocean floor than they had expected? Because the ocean floor is much younger than they expected, so it had not had enough time to accumulate sediment. 72. Describe the movement of the plates at ridges and trenches. Plates are moving closer together at trenches, while at ridges, they are moving apart.

The birth of plate tectonics Q. 75 Are earthquakes randomly distributed over the Earth or are they concentrated in certain areas? They are concentrated in certain areas. Q.76. What are the areas described above called? What do they represent? They are known as seismic belts and they represent the borders between plates.

Mountain orogeny summary Orogeny = mountain building Plate tectonics used to explain mountain building Plate collisions- 3 types: oceanic-oceanic oceanic-continental continental-continental Forces: tension, compression, shear Mountain types: faulted, folded, volcanic, complex Know examples of each *

Q.59 Page 23.Why can we find sea-fossils on top of the mountains?

Page 23. Q. 59 This is because when two continents collide, the marine sediment found in their continental shelves folds, changes shape and is pushed up, so the marine sediment forms part of the new mountain range formed during collision. Therefore, any marine fossils originally found in the marine sediment can then be found on the mountain range.

Isostasy (Greek isos = "equal", stásis = "standstill") is a term used in Geology It is a term used in Geology to refer to the state of gravitational equilibrium between the earth's lithosphere and upper part of the Mantle, such that the tectonic plates "float" at an elevation which depends on their thickness and density.

Unit 9 Page 10. 18. Explain, using isostasy, if the lithosphere would rise or fall in these situations: a) Erosion of a mountain range. Rise b) Deposit of sediment in a sedimentary basin. Fall c) Rising of a mountain range. d) Formation of an ice cap.

A similar process occurs with mountain building and mountain erosion. The addition of glacial ice on the Earth's surface causes the crust to deform and sink (a). When the ice melts, isostatic rebound occurs and the crust rises to its former position before glaciation (b and c). A similar process occurs with mountain building and mountain erosion. Source: PhysicalGeography.net