Deserts, Glaciers, and Climate

1. Compare the geological features of a desert landscape and glacial landscapeBasically, a desert is a type of region or landscape with very little precipitation. Geographically, a desert has very high temperatures at day and low temperatures at night.

The reason for this is because the desert air is so dry that it cannot block sunlight during the day nor can it trap heat during the night (Britannica Encyclopedia, 2008). Most deserts are formed due to rainshadows, which are mountains that block the pathway of precipitation to the desert (Britannica Encyclopedia, 2008).Usually, deserts are composed of rocky surfaces and sand. Certain parts of the desert surfaces are also comprised of ergs, which are sand dunes that are also made up of plateau landforms and hamada, which are stony surfaces that are formed by sand seas. The landscape also has visible rocky terrain (Britannica Encyclopedia, 2008). Other geological features of the desert include desert soils, fluvial deposits, oases, and bedrocks, among others (Britannica Encyclopedia, 2008).

Moreover, a desert also consists of dunes, which are geological features that consist of hills of sands that are created by the aeolian process. This process refers to the wind’s activity and particularly, its ability to form and manipulate the Earth’s surface (United States Geological Survey, 1997). Basically, a wind can transport, deposit and erode material and are highly effective agents in certain regions that have little vegetation and large amount of unformed or unconsolidated elements (United States Geological Survey, 1997).Due to the ability of the wind the shape the surface of the earth, different types of dunes are formed.

These include the longitudinal dune which consists of narrow and long ridges that are parallel to the prevailing wind; the barchan dune which is a crescent shaped dune that point downward across an irrigated field and formed on flat and hard desert floors where the wind is constant and where the supply of sand is limited; the transverse dune which merges with the barchan dune to form asymmetrical and continuous ridges that are perpendicular to the strongest winds; the star dune which are formed by the blowing of the wind in all directions, forming stationary, isolated, star-shaped dunes; and the parabolic dune which are open ends of V or U shapes that face the upwind (Strahler, 2005).On the other hand, glacial landforms are the result of the massive movement of large sheets of ice during the Ice Age. Commonly called glaciers, since the end of the ice age, they are now only developed in certain parts of the world particularly in Antarctica, Greenland, and the highest mountains of the globe (Britannica Encyclopedia, 2008). Basically, the types and geological features of glaciers can be narrowed into two classifications: valley or mountain glaciers and ice sheets or continental glaciers (Britannica Encyclopedia, 2008).Generally, glaciers are modified by a several processes that ultimately result in the formation of certain rocks and deposits.

One noticeable process is erosion, which can take place through two methods: plucking and abrasion (Britannica Encyclopedia, 2008). Plucking happens when a glacier moves over the fractured surface of the bedrock and then softens and raises the blocks of rock into the ice. On the other hand, abrasion occurs when the rock fragments and the ice slide on the bedrock which polishes the surface below and as a result, forms pulverized rock called rock flour (Britannica Encyclopedia, 2008). In other words, other than ice of different shapes and sizes, due to several processes, sediments and rocks are added to the geological features of glacial landforms.Basically, the main difference between a desert and a glacial landscape is their origin. Deserts are formed by blocking precipitation or rainfall why glacial landscapes are formed by movements of ice.

Moreover, the formation of the various geological features of the desert is highly dependent of the movement and activity of the wind while glacial landforms are dependent of the movement of the ground and the ice.2. Summary of climate changes from past to present and prediction of the Earth’s futureAccording to the reading, basically, in the past, long before technology was well-developed, the only thing sure about climate change is that for the past 800,000 years, the Earth has been undergoing a period of cooling but with alterations of glaciations or ice ages that lasted for 100,000 years and followed by warm years called interglacial periods. In short, in the past 2 million years, more or less 20 ice ages have occurred and at present, the earth is nearing the peak of a warm interglacial period, which explains why it is hotter today than the previous years.Other notable climate changes that have happened in the past include the formation of the Isthmus of Panama, which connected North and South America. This developed destroyed the connection between the Pacific and Atlantic oceans and also significantly altered the circulation in the ocean and the atmosphere, which ultimately led to major changes in the global climate.

Moreover, astronomical factors have also contributed to major changes in the Earth’s climate.Based on the reading, the Earth’s eccentricity (the planet’s departure from circularity), the tilting of its axis of rotation, and the wobbling or precession of its axis all determine how much radiation from the sun will reach the Earth’s surface and on what specific times of the year. However, all of these factors that affect climate are moderated by the greenhouse effect. The greenhouse effect is a natural process wherein carbon dioxide, methane, and water vapor store heat that comes from the surface of the Earth and sends it back downward.

On the other hand, at present, possibly most the notable climate change is the constant and rapid increase in the levels of carbon dioxide in the past 50 years.This increase is the result of a highly industrialized human world which gives off more or less 8 billion tons of carbon, mostly in the form of carbon dioxide, into the atmosphere yearly. More importantly, many believe that this rapid increase in carbon levels would eventually lead to global warming, which also explains why every year the Earth’s temperature is becoming hotter.Basically, based on recent climate and geological changes, my prediction is that the temperature in all parts of the Earth will increase and become hotter in the future. The warming of the Earth’s atmosphere is evident in the increase of the ferocity and frequency of typhoons, among others. Moreover, the melting of the Earth’s largest icecaps causing water levels to rise is another sign that hotter temperatures are in store for everyone in the future.

However, I still believe that even if this climate change in the form of global warming does submerge the lands of the Earth underwater, it will again pass the natural cycle of re-cooling and, ultimately, things will get back to normal.