Aeolian Features and Processes - Assignment Example

Question One On Blackboard you will find an image of a small region of the southern hemisphere of Mars. This image has several features indicative of fluvial erosion and deposition as well as aeolian activity. Clearly identify each of the features consistent with fluvial activity, and make sure to indicate which features are dominantly erosive and which are depositional. Then, describe in words the geological activity in this scene and an interpretation of the processes involved. Be specific in your description and focus directly on the features in the scene, not generic fluvial activity The features labeled A and B are associated with fluvial deposition while those labeled C and D relate to fluvial erosion. The features labeled E and F are formed as a result of Aeolian activity. Each of these features and processes are discussed in the sections below. Fluvial Erosion and Deposition Fluvial erosion and deposition refers to the changing of the landscape of a planet due to the movement of water on its surface. Specifically, fluvial erosion happens when debris is moved from a place as water flows and thus the place is left with a natural trench as the natural material that existed at that place is washed away by water. On the surface of Mars, there is evidence of fluvial erosion (Lancaster, 1). For example, the features labeled C and D were formed due to fluvial erosion. They are natural trenches that were formed as a result of water flowing and moving debris with it as it did. This happened millions of years ago when Martian surface could allow liquid water. When debris is moved by water from one place due to fluvial erosion, it is deposited at a different place. This process of depositing debris is called fluvial deposition. In the Martian image provided above, fluvial deposition is represented by A and B. The features look like hills on the image since they comprise of materials that were deposited as fluvial erosion occurred. Aeolian Activity This refers to change in a planet’s landscape due to wind. When wind blows on the surface, it carries some materials and debris along with it (Lancaster, 1). The difference between Aeolian and fluvial activities is that Aeolian activities do not leave deep trenches like fluvial activities do. In the image, E and F show Aeolian activity as it shows sections that look like valleys; where materials have been carried away from. This happens considering that Mars has some of the strongest winds that even cause wind storms that last for years. Question Two On Blackboard you will find a Powerpoint file with images of various faults. For each image, indicate a. The location of the fault(s) b. The direction that each side of the fault has moved c. The name of the type of fault in the image. Image 1 Image 2 A fault refers to a fracture or breakage in a rock that has been caused by the movement of earth and which leads to a significant displacement of a mass of earth from its original position to a new position. As a result, one point of the mass shifts either down, or right, or left of its original position. For example, in the image that has been labeled ‘Image 1’ the fault lines are indicated as A and B. the displacement in A was bigger than the displacement in B and therefore the land slid more downwards in A than in B. In the image labeled ‘Image 2’, the fault line is represented by C and it shows movement in form of a curve that makes the dip to be steeper near the surface and shallower as depth increases. Therefore, the locations of the faults are A, B and C. In image 1, the fault has caused displacement from up to down while in image 2 the displacement is from left to right. This displacement is important as it tells direction. In image 1, the direction of the fault is vertical while in image 2 it is horizontal to the right. The image labeled image 1 shows a normal dip slip fault. This is because the hanging mass of earth has moved downwards relative to the foot mass. In the image labeled image 2, the fault is a listric fault since it is almost perfectly horizontal except for the fact that the dip is steeper than the surface. Question Three On Blackboard you will find a PowerPoint file with an image that contains evidence of a portion of Mars that contains multiple indicators of aeolian activity (for reference the large crater in the image is ~750 meters in diameter). Locate and indicate good examples of each type of landform. Then justify whether or not you think that each of these landforms is consistent with the same wind pattern. There are various Aeolian landforms which include yardangs, lag deposits and ventifacts. On the surface shown above, the landforms are labeled as A, B, C and d where A shows ventifacts, B shows a yardang, C shows an erosion and D shows lag deposits. A ventifact is formed when the existing land is raised after debris is deposited from one place to another. A yardang is formed when wind shapes the material without necessarily going through the process of erosion or deposition. A ventifact is land that is left without material due to wind erosion and finally lag deposits refer to situations where debris and materials are deposited at one place from another place. Question Four Below is a list of a few unresolved questions in planetary science. Choose one of these questions. Then prepare a written discussion taking one of the following viewpoints. a. Justifying why this is an important fundamental question worthy of further study. b. Justifying why this is not an important, fundamental question worthy of further study. c. Discuss approaches to solving this problem and why these approaches are appropriate to the question. Possible topics include (pick only one) • When did Mars last have liquid water at its surface? • How are chondrules formed? • How much tectonic activity has there been on Mercury? • How did material similar to calcium aluminum-rich inclusions end up in cometary materials such as found by Stardust? • What is dark matter? The topic of my choice is ‘When did Mars last have liquid water at its surface?’ and the viewpoint that I will pick is ‘Justifying why this is an important fundamental question worthy of further study’. Mars has become a center of attention whenever the human race focuses on the possibility of domesticating a planet for the sake of making it a habitat for human settlement. However, settlement requires that the region should be able to sustain life; which cannot happen unless there is adequate water in liquid form. The answer as to when Mars had liquid water on its surface will come with many revelations including why the water disappeared, ways of making the ice water in the subsurface to liquefy and come to the surface and whether there can be abundant water to sustain life of any kind. For instance, science holds that Martian water disappeared billions of years ago due to the planet’s loss of its atmosphere; a factor which led the planet’s temperature to drop below freezing point. This ensured that all the liquid water that existed was converted to solid water. Understanding this is important as it can indicate whether the same process that saw the loss of the planet’s atmosphere can revert naturally or artificially with time (with specific interest on the time period it would take) In understanding when liquid water last existed on Martian surface, it becomes easy to understand ways of liquefying the subsurface ice that has been proven to exist on Mars. This is because an examination of the processes that led to its freezing can result in ways of ensuring that the necessary conditions are put in place so that it does not freeze again. Ultimately, understanding the concepts above will make it clear as to whether the planet can be domesticated or not and if it can be domesticated, it will be easy to understand for how long its water can be sustained in liquid form. Question Five The plots below represent the results of one possible way that the solar system evolved after the gas from the protoplanetary disk was gone. The four circles, each in a slightly different shade of gray, represent the four giant planets in our solar system. Each of the black dots is a smaller minor body. If all these smaller bodies were placed together in one body it would have the mass of 35 Earths. Each plot represents a particular time in the evolution of this solar system model. Also shown is the time point after formation of the Sun that each plot represents Your task is to very carefully examine each panel and to deduce two things: (1) What is the sequence of events that occurs between panel (a) and panel (d)? and (2) What would be the likely consequences for the Earth and Moon of this scenario? Pay very close attention to the similarities and differences between each plot. Prepare a written description explaining what appears to be happening (1 above) with details and reference to the panels of figures. Also describe the consequence for the Earth and Moon (2 above), preferably with some discussion of whether these consequences are consistent with what we know about these bodies at around this timeframe. From the diagram, panel a represents the initial stages after the formation of planets and moons. Due to availability of so much matter and debris, there are so many small moons which orbit the large planets. This is because of the fact that the gravitational force of the large planets is able to keep the small moons in orbit positions. However, since they are small, their orbits will be altered every now and then due to the attraction force of the planets and therefore the moons will tend to move towards the planets. This distortion of the orbits and attraction towards the planets makes the moons to be concentrated more closely to the ring of the planets and thus justifies the concentration that is evident in panel b. However, the same concentration and alteration of the moons’ orbits makes them to collide a lot among themselves and with the planets which keep attracting them. The collisions have two main effects; first, they reduce the number of moons as some moons combine under the collision pressure and second they alter the eccentricity of the resultant moons and their distances from the planets. This explains why in panel c the moons seem to be wildly scattered and some have moved very closely to the planets (since the planets’ gravity is very strong and always pulls debris that have altered orbits). Therefore, there is constant collision with the planets as well. However, continued combination of the moons gives the resultant bodies enough mass to resist planetary attraction while at the same time reducing the number of moons and continued changing of their orbits eventually settles them in specific distances and orbits from the planets. This explains why panel d has fewer moons that have specific orbits. The process explains what happened between the moon and earth. Both were formed from debris of the big bang but the earth was much bigger than it is and the moon either never existed or was much smaller (plane a and b). A collision between earth and a bigger body resulted in a lot of material (in form of small moons) being detached from earth and this material collided and attracted each other to form one solid mass; the moon as we know it. Eventually, earth’s gravity settled the moon in its orbit. Works Cited Lancaster, Nicholas, Aeolian features and processes, The Geological Society of America, 2009, Pp. 1 - 25 Read More