Waking The Giant Flashcards
Chapter 1-3
Approximately 4 billion year ago there was a cataclysm, perhaps the most important we know of. What was it and why is it so important?
Early earth collided with a large object called Theia. During the collision, Theia disintegrated. Earth was damaged but remained more of less whole. Some of Theia’s mass was absorbed by Earth to give it a bigger core. This may have given Earth a stronger magnetic field and more solar protection.
The rest of Theia formed a “cloud” of debris around Earth that eventually collapsed to form the moon, A larger moon causes significant tides in earth’s ocean.
What was the ‘Great Oxidation Event and why is it so important?”
The appearance of significant amounts of oxygen in the Earth’s atmosphere. As oxygen accumulates in the atmosphere, new opportunities for life to evolve appear; and life does evolve. However, the more primitive life forms that already exist are now restricted to where they can live. Oxygen is poisonous to them. Also the chemistry of the atmosphere changes with the presence of oxygen and it’s ability to form other molecules such as CO2.
What was the ‘Great Dying’ and why did it happen?
The largest known mass extinction about 250 million years ago at the end f the Permian period.
This thought to have been the result of large, sustained volcanic eruptions in what is now Siberia in Russia.
Effusive eruptions (non explosive like Hawaii) released large concentrations of CO2. This then changed the nature of the atmosphere and oceans.
What is the PETM and how did it happen?
Paleocne Eocene Thermal Maximum.
What is the Pleistocene Ice Age and how was it started?
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What is the Eemain Interglacial?
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What is the Younger Dryas and how did it happen?
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The four events listed in question 1 - 4 describe the Earth’s climate at various stages in the past. Why do these events say about our climate and why is this so important?
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There is little doubt that volcanic eruptions have had a significant impact on the Earth’s Climate. What are the three things from a volcanic eruption that have the greatest impact on Climate. Briefly explain each.
Volcanic eruptions release abundant gas that can cause climate change. These include:
- Sulfur Dioxide. In the atmosphere it reacts with water to provide sulfuric acid. This absorbs and blocks solar radiation causing the earth to cool.
- Carbon dioxide. This gas traps solar radiation which warms the earth.
- Other volcanic gasses such as chlorine that depletes the ozone layer.
What is the asthenosphere, how does it form and why is this so important.
The lower crust and upper mantel (100-250km deep) that is partially melted. Only about 10% has melted. More of it is close to melting. The asthenosphere is the primary source of magma due to pressure induced heat.
What is Paul’s Volcano and why is it significant?
An active stratoVolcano in Alaska near the Pacific Ocean. It is important because it tends to erupt only during certain times of the year - in the winter.
The regular eruption pattern of the volcano is thought to be cause by higher sustained sea level and therefore more weight at the coast caused by winter winds blowing fro the Pacific Ocean to the coast. This additional weight changes the crust in and around the volcano causing it to bend differently. This change in the crush then changes the volcano in such a way that magma reaches the surface more easily.
What is the ‘volcano season’ how does it happen?
A regular pattern of eruptions related to weather and climate, The underlying cause is changes in the distribution of weight in the form of water, as part of the water cycle. Inparticular this changes:
- Changes in sea level
- Changes in precipitation
- Changes in glacial ice,
The idea that climate change has significant impact on volcanic activity is based on three factors. Explain each.
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