Part A: Short-Answer Questions (20 points in total)
Answer the following questions as succinctly as you can. None of the answers should be more than a couple of sentences (100 words or less).
- List the various factors that govern the wavelength and amplitude of wind waves. (2 points)
- Explain why waves get refracted in near-shore areas, and describe some of the implications of this refraction. (3 points)
- Explain the mechanism that has resulted in the presence of post-glacial aged marine deposits tens of metres above present-day sea level at numerous locations along the British Columbia coast. (3 points)
- Describe the property of greenhouse gases that enables them to trap heat within the atmosphere. (3 points)
- Explain the role of albedo in the Earth’s climate, and give an example of an albedo change that is a positive feedback mechanism. (3 points)
- List some of the things that we do as individuals that contribute most significantly to climate change. (2 points)
- Describe the geological origins and timing of the Appalachian fold belt of eastern North America. (2 points)
- Explain what makes the Queen Charlotte Fault a transform fault. (2 points)
Part B: Exercises (45 points in total)
B1: Interpreting waves (15 points)
Figure A5-1 is an aerial view of waves approaching Long Beach on Vancouver Island.
- Using the drawing tools in Word[1], draw in a few lines to show the predominant orientation of the crests of unrefracted waves approaching this coast. (4 points)
- What is the approximate wavelength (in metres) of the unrefracted waves?
(2 points)
- If the amplitude to wavelength ratio is 0.02, what is the amplitude of the unrefracted waves? (2 points)
- Point out some locations where the waves are being refracted, and describe how they are changing. (4 points)
- Describe in words, or show with an arrow, the likely direction of the longshore current under these conditions. (3 points)
Figure A5-1. Waves approaching Long Beach, Vancouver Island, June 2012. Image © Digital Globe Data SIO, NOAA, U.S. Navy, NGA, GEBCO, © Google, © TerraMetrics (Image © Digital Globe, TerraMetrics, Data SIO, NOAA, U.S. Navy, NGA, GEBCO, Map data, © 2018 Google)
B2: Measuring rates of atmospheric CO2 increase (15 points)
Figure A5-2 is similar to Figure 5-6 in Unit 5, except that a trend line (black) has been fitted to the data. The levels of CO2 in 1960 and 1970 are shown (316 and 325 ppm, respectively), and this 9 ppm difference equates to an average increase in CO2 concentration of 0.9 ppm/year over that period.
- Using the same method, determine the annual rates of CO2 increase between 1985 and 1995 and between 2005 and 2015. (6 points)
Figure A5-2. Atmospheric CO2 concentrations as measured at the Keeling Lab on Mauna Loa, Hawaii. © Steven Earle. Used with permission. Data Source: Scripps Institution of Oceanography.
- In 1992, countries around the world (including Canada) signed the Kyoto Protocol and committed to reducing their CO2 emission levels, and most of the signatory countries implemented changes over the following two decades. Comment on what the data in Figure A5-2 tells us about the collective success of these changes. (4 points)
- What accounts for the saw-tooth nature of the Earth’s CO2 curve (the pink line on the graph)? It may help to refer to the inset showing the data for 1998 and 1999 in detail. (5 points)
B3: Terranes and the Mt. Polley map (15 points)
As shown in Figure A5-3, the Mt. Polley map area is almost entirely underlain by Quesnel Terrane rocks, although small parts of two other terranes also are represented on the map—the Cache Creek Terrane in the southwest and the Kootenay Terrane in the northeast. Most of the Quesnel Terrane in this area is volcanic and sedimentary in origin. You should refer to this map when answering the questions below, but the answers can be found on the Mt. Polley map (Geoscience Map 2007-1: Regional Geology of the Mount Polley Area, central British Columbia. Copyright © Province of British Columbia. All rights reserved. Reproduced with permission of the Province of British Columbia), and in the legend.
Figure A5-3. Overview of the terranes represented on the Mt. Polley map. (The Quesnel and Cache Creek Terranes are part of the Intermontane Superterrane, and the Kootenay Terrane is part of ancestral North America.) © Steven Earle. Used with permission.
- What type of rocks make up the Cache Creek Terrane in this area, and how old are they? (3 points)
- What type of rocks make up the Kootenay Terrane in this area, and how old are they? (3 points)
- When the Quesnel Terrane was accreted onto North America in the early Jurassic (at around 185 Ma), it already included some intrusive igneous rocks, but other intrusions appeared later. Identify the post-accretion intrusive igneous rock(s) (i.e., rocks that were intruded after the accretion) and indicate their age(s). (3 points)
- Some sedimentary and volcanic rocks and some still-unconsolidated sediments were deposited in this region after the early Jurassic terrane accretion event (after 185 Ma). Identify these units and indicate their ages. (6 points)
Part C: Longer Questions (35 points in total)
Please answer the following questions. Write as much as you think is necessary to address each question but be as concise and clear as possible. Feel free to use point-form or a table rather than standard essay format. You do not need to reference the text or the material in the course units (excluding images and quotations), but if you use any outside sources, provide in-text citations. Use any referencing style that you are comfortable with.
- Describe the various landforms of coastal erosion, including sea cliffs, sea caves, arches, stacks, and wave-cut platforms. Explain how they form and how they are related to one another. (15 points)
| Sea cliffs | |
| Sea caves | |
| Arches | |
| Stacks | |
| Wave-cut platforms |
- Western Canada’s two main mountain ranges are the Rocky Mountains and the Coast Range. Compare these two ranges from the perspective of their geological (tectonic) origins, major rock types, and ages. Show the approximate extents of the Rocky Mountains and the Coast Range on the map below. (20 points)
| Range | Geological Origins | Rock Types | Age |
Figure A5-4. © Steven Earle. Used with permission
[1] Inside Word, click on the drawing itself, and then under the Insert tab, click Shapes. If you are unable to use the drawing tools in Word, print the image, draw on it by hand, take a photograph, and insert it in your Word document.
