iGeo 2012, Писмен тест — Задача 14. Section C: Climate and Climate Change
Written Response Test — Question and Answer Booklet — 9th International Geography Olympiad — Cologne, Germany — 21–27 August 2012 · 21 август 2012 г. · 3 т.
Внимание: Бележка към темата
The Source Booklet (Sources A1–F1) referred to in the questions is not part of this paper's files; only the copies of Source B1 Maps A and B and Sources E1 and E3 printed in the answer booklet are reproduced.
Instructions for the students
- This test consists of 6 sections.
- The maximum total mark is 90. The mark for each question is given at the beginning of the question.
There are a maximum of 15 marks for each section. - Give only the required number of answers (reasons, examples, et cetera). For instance, if the question asks for 2 reasons and you give more than 2, only the first 2 reasons will be marked.
- Answer all questions in the spaces provided in this booklet.
- Check the backs of pages as questions are printed on both sides of a page.
- Fill in your name, team and student number on the front page of this booklet.
- Fill in your iGeo student number in the boxes on top of the pages in this booklet.
- The Source Booklet contains the maps and figures referred to in the questions.
- Time: 180 minutes for non-native English speakers; 150 minutes for native English speakers.
- Non-native English speakers may use bilingual dictionaries during the test.
- You may use a calculator during the test.
- You may use the atlas provided during the test.
Good luck!
Marking scheme - overview
| section A | section B | section C | section D | section E | section F |
|---|---|---|---|---|---|
| 1 - 2m | 1 - 1m | 1 - 3m | 1 - 3m | 1 - 4m | 1 - 4m |
| 2 - 1m | 2 - 1m | 2 - 3m | 2 - 8m | 2 - 1m | 2 - 2m |
| 3 - 4m | 3 - 1m | 3 - 3m | 3 - 4m | 3 - 3m | 3 - 3m |
| 4 - 1m | 4 - 9m | 4 - 2m | 4 - 1m | 4 - 6m | |
| 5 - 1m | 5 - 3m | 5 - 4m | 5 - 1m | ||
| 6 - 2m | 6 - 3m | ||||
| 7 - 4m | 7 - 2 m | ||||
| 15 marks | 15 marks | 15 marks | 15 marks | 15 marks | 15 marks |
Условие
Describe the thermo-haline (thermo – relating to temperature, haline – relating to salt) circulation in the North Atlantic Ocean.
Решение
3 marks
Describe three elements:
- Circulation to the north (warm) ½
- Circulation to the south (cold) ½
- Circulation on the surface ½
- Circulation in the bottom (down) ½
- Change in the density – cooling, freezing, salt (one of these) 1
Description
Thermohaline circulation is driven by differences in density.
Warm salty surface water flows north from the Atlantic Ocean towards the Arctic. As the water flows north, heat picked up in the tropics is transferred into the atmosphere and the temperature of northerly seas is raised. This means countries in northwest Europe such as Norway and Denmark experience more temperate climates than their latitude suggests they should.
The Atlantic water cools as it approaches the Arctic. A combination of evaporation into the atmosphere and cooler Arctic temperatures increase the water’s density. That density is further increased by brine (salt saturated water) dripping from the sea ice as it forms.
This water eventually becomes so dense it overturns – sinking down into the depths of the Arctic Ocean to begin flowing south again. This process is known as North Atlantic Deep Water formation. It is vital to thermohaline circulation.
Оригинал в Архива: 2012WRTQandA.pdf · официални решения: 2012WRTmarkingscheme.pdf