Critical Thinking Questions
Chapter 1: Critical and Creative Thinking Questions 1 And 4
Question 1
Some of the indicators for mechanical weathering in my area are the following: high number of boulders with cracks and joints, fracturing at the surface of rocks and old buildings, slow disintegration of boulders and statues, and surface fracturing on roads and slopes of various hills. On the other hand, the evidences of chemical weathering are; change in color of rocks, darkening of old buildings made of limestone, and gradual wearing out of rocks and walls of some buildings. The significance of these indicators can be determined by comparing the magnitude of the evidence and changes in weather and land scape. Normally, presence of high number of boulders with many cracks and joints signifies high temperature or high frequency of frost. It may also indicate increased tectonic movement. These evidences can be used to assess how safe an area is for construction of buildings.
Question 4
Both slope failures and flows occur where I live. Tilted electrical poles, trees and buildings are signs suggesting that mass wasting is taking place and are present where I live. The rate at which regolith is moved down a slope can be determined through observation of the degree of tilting of buildings and trees found on the slope. Besides, the rate at which trees and buildings lying along a slope fall can also indicate the rate of mass wasting. For instance, slopes that exhibit high rate of movement of regolith is likely to show high rate of falling of tall trees.
Question 1
Estuaries are shallow because they are formed near the sea shores when a stream entering a sea is blocked by a head land such that it does not enter the sea directly. This leads to accumulation of sediments over a long period of time which further makes the estuary shallower.
Question 3
The 25 billion tons of soil lost every year through farming end up in beds of seas, oceans, and lakes and deep inside the earth crust. Soil is lost through soil erosion and leaching. Eroded soil is carried by flowing water and wind to the ocean and seabed where they accumulate and cause the bodies to be shallow. Some of the soil is lost through leaching whereby minerals in the soil are dissolved in water and chemicals used in farming. The water then carries the minerals into the ground.
Question 4
If the depth of sedimentary rock strata is 14km and the oldest stratum was formed 150 million years ago, then the rate of deposition is 9.3333*10-8km per year. This is determined by dividing the depth of the sedimentary rock strata by the period that has passed since the formation of the oldest strata.
Chapter 11: Critical and Creative Thinking Questions 2 & 3
Question 2
Many aspects of water have defined and continue to define human life in the planet Earth. Many wars have been fought over scarcity of water. Scarcity of water has also defined migration pattern of different people. As a matter of fact, the ancient people used to settle in areas close to sources of water. Where people live and how they live is largely dependent on the availability of water. Hardships resulting from disasters associated with water such as flooding have led to mass migration of people from one place to another.
Humanity has always responded to effects of water shortages and disasters associated with water in various ways. For instance, ancient Chinese harvested rain water to avert water crisis during dry seasons. Technological advancement is one of the means through which mankind has sort to tackle water crisis. For instance, development of technology for drilling boreholes has significantly helped in tackling water shortages.
Question 3
The concept of residence time also applies to glaciers and air. Air and glacier move from one reservoir to another in the earth system. It is important to monitor residence time of these substances in order to assess the stability of the earth system at any particular time. Besides, these substances define most conditions of the earth such as weather.
Chapter 13: Critical and Creative Thinking Questions 1, 2, & 5
Question 1
Factors contributing to formation of rain shadow, coastal, and continental desserts are wind patterns, pressure systems, and ocean currents. Rain shadow dessert is formed when a mountain blocks moist air making all the moisture to fall on the windward side. This leaves air crossing over to the leeward side with little moisture hence the air absorbs the little moisture available in the air at the leeward side. Coastal desserts on the other hand are formed when winds blowing towards land passes over cold ocean current. This makes the wind cold hence reducing its ability to absorb moisture. This wind therefore causes no precipitation at the coast hence making the land adjacent to the sea dry. Continental desserts are caused in similar manner as the rain shadow desserts. In this case, winds flowing from the sea towards land lose its moisture before reaching interior lands. When it finally reaches however, it is dry hence has no moisture. Consequently, it absorbs more moisture hence making the land dryer.
Question 2
Sahelian zone in Niger is highly prone to soil erosion. Some of the soil erosion control techniques applied in this region include tree planting, zai, and regeneration of natural woody plantation. In the US however, techniques such as strip cropping, raising wind breaks, and mulching are highly exploited.
Question 5
The rapid retreat of glaciers recorded over the past two decades is mainly due to increase in global temperature. This has caused ice sheets to melt hence leading to the retreat. The retreat is mainly attributed to anthropogenic processes. This is mainly due to the fact that global warming is mainly caused by the release of greenhouse gases into the atmosphere. These gases result from industrial activities. Currently, most glaciers are retreating. For instance, Franz Josef glacier is undergoing a rapid retreat. According to Mills (2012), the glacier is retreating at 125 meters per year.
References
Mills, L. (2012). Franz Josef Glacier's 'rapid' retreat. The New Zealand herald. Retrieved fromhttp://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10818264
Murck, B. W., Skinner, B. J., Mackenzie, D., & National Geographic Society (U.S.). (2008). Visualizing geology. Hoboken, N.J: Wiley.
