...science as a whole; scientists are constantly making new observations to develop solutions which are then accepted, rejected, and retested by others. The snowball earth hypothesis and controversy together reveals the significance of innovation and scientific debate to the progress of science. The snowball earth hypothesis was first introduced by Joseph Kirschvink after years of other scientists finding peculiar continuous layers of limestone (calcium carbonate rock) or dolostone (magnesian calcium carbonate rock) within other layers of rocks near the equator. These limestone or dolostone layers are called “cap carbonates”, and they form on top of sedimentary rock after major glaciation periods (Hoffman). Therefore, scientists can use observations of cap carbonates to date the time and duration of glaciation periods. Kirschvink suggested that a snowball earth could...
Words: 1530 - Pages: 7
...following: Describe the various geologic events that have occurred in the region around your feature. Describe the geological features and various types of rocks that formed in the area, such as mountains, craters, canyons, volcanoes, fault lines, or folds. What is the most prevalent rock type of your feature? Describe the rock type’s mineral composition. How old is your geologic feature? Estimate the absolute age of the feature, and discuss methods used to determine the age. What geologic event created your feature? Discuss the process of plate tectonics related to the formation. Explain the significance of igneous, sedimentary, and metamorphic rocks in your region. Describe the types of weathering and erosion processes that have likely affected the physical appearance of your feature. Describe any significant water, ocean, desert, or glacial features associated with your region, and the process involved with creating one of them. Explain what resources are abundant in the region and the importance and economic value of these resources to the region. In conclusion, explain why you selected this geologic feature for your presentation. Include graphics. Include details in speaker notes . http://wisconsingeologicalsurvey.org Climate change—the long view Updated December 12, 2011 URL: http://www.uwex.edu/wgnhs/reverse_grading.htm © 2009 by Board of Regents of the University of Wisconsin System Equal Opportunity/Affirmative Action...
Words: 2406 - Pages: 10
...This would be roughly 6,000 years after the retreat of the Wisconsinan glaciation. The deglaciated terrain would need sufficient time to develop a soil profile substantial enough to support the needs of the Basswoods. The succession of the area would have begun with the pioneer species that, after an ample period of time, would have broken down the bedrock and provided organic materials to create soils. Therefore, we cannot expect Basswoods to occupy the deglaciated terrain until subsequent stages of succession. Additionally, the Basswoods require damp soils in order to grow and reproduce. Moist soils would imply moist environments. The time period that best allows for a moist environment based on palynological evidence is approximately between 8,500-5,000 years ago. This was a warm and wet period after the glaciations of the Northeast. The cool and dry climate that existed before this time period, as indicated by Menking et al. (2012) would not have been an ideal climate for the expansion of...
Words: 1608 - Pages: 7
...eference is likely to be made to changes in the dominant processes – from vertical erosion nearer the source to lateral erosion becoming more dominant lower down. Deposition may also be referred to here. There should be understanding of these, why they are dominant in different sections and the impact they have on the valley cross profile. Reference to reasons for this relating to graded profile, the effect of height/gravity in connection with potential energy and the impact of increasing discharge on kinetic energy are valid here. May refer to meander migration in connection with widening the valley. May refer to other factors, such as geology, rejuvenation, glaciation, mass movement, quarries. Level 1 (1-4 marks) Is aware of the changing processes responsible. Begins to explain – in the context of erosion/deposition processes. Some use of appropriate terminology present at the higher end. Level 2 (5-7 marks) Processes responsible are linked clearly to changing shape. Explanation is developed, with reference to underlying reasons – changes in energy, links to graded profile/base level. Appropriate geographical terminology is used. (4 marks) AO1–1 AO2–1 AO3–2 1 (a) (ii) 1 (b) (4 marks) AO1–1 AO2–1 AO3–2 (7 marks) AO1 – 4 AO2 - 3 Geography 2030 - AQA A Level Mark Scheme 2010 June series Section A Question 1 5 Geography 2030 - AQA A Level Mark Scheme 2010 June series 1 (c) Content will depend on case studies used. Flooding may be defined within the answer...
Words: 330 - Pages: 2
...ESCI 1040 Test 2 Due March 29, 2011 Directions: Answer the following questions in your own words using your text (ch 7-10 and 12). Several of the questions refer to multiple chapters. Please keep in mind that because this is a take-home, open book test, your answers should demonstrate that you understand the material. Your answers should be well thought out, complete yet succinct, well written, with references cited. This is not a group effort; please make sure your work is your own. Please be careful with the use of images, if you do not explain your images you will receive no credit for them. Please e-mail me the test completed, including the multiple choice questions that follow the essay/shot answer questions, as a doc, docx or pdf file. Good Luck! 1. Differentiate between relative and absolute dating. List, define and discuss the principles used to define relative age. Discuss isotopic dating: what atomic particles are involved, what are some common isotopes that are used, and what are some uses of isotopic dating? Be sure to explain the calculation of the age of a rock. Relative dating is telling us the age of something compared to that of the substances around it, more plainly stated the sequence of events. Absolute dating tells how old something is, an amount of time can be associated with an object unlike in relative dating. There are four stratigraphy principles used to determine geologic history of a locality or a region: 1) original horizontally...
Words: 4905 - Pages: 20
...Fluvio – glacial landforms The aims of this booklet are to help you fully understand how Varves, Kames, Eskers, outwash planes, stream terraces and Kame Terraces form. They are all landforms of fluvio glacial origin. Read through the booklet and add the locations of each landform to the map of North America below, ensuring that you record what landform it is and the place name Kame Deltas Define what a Kame Delta is; Define what a Kame Delta is; In the box draw a sketch diagram of the Kame Delta indicated, adding labels to show key relief features In the box draw a sketch diagram of the Kame Delta indicated, adding labels to show key relief features Fully explain how a Kame Delta forms, mentioning sediments, erosion, deposition, rivers discharges and braiding. Fully explain how a Kame Delta forms, mentioning sediments, erosion, deposition, rivers discharges and braiding. A large kettle hole near Dorback Lodge, developed in thick meltwater deposits and set within a series of moraine ridges A large kettle hole near Dorback Lodge, developed in thick meltwater deposits and set within a series of moraine ridges Kame and Kettle topography - Kettle Lakes Describe the shape of the Kettle hole and its situation Describe the shape of the Kettle hole and its situation Explain how kettle holes form using the diagrams below. You could use http://www.fettes.com/Cairngorms/kettle%20hole.htm to help Explain how kettle holes form using the diagrams below. You...
Words: 1072 - Pages: 5
...As regions of Mediterranean climate generally experience hot, dry summers and cold, wet winters, plants within them must have evolved to suit these environments. Rich diversity can be seen in much of the Mediterranean flora, prompting scientists to believe that speciation events and evolutionary processes, ranging from colonization to isolation, must have occurred over time allowing these plants to thrive in this specific climate. There is evidence of ancient isolation occurring in the Miocene and early Pliocene, as the separation of African and Eurasian tectonic microplates (surrounding the Mediterranean basin) led to geographical isolation of many species, which were now on separate sides of the landmass. Further isolation occurred due to frequent glaciation episodes experienced by the European landscape. During this time, the Basin served as refuge for many organisms, which later recolonized the areas affected by glaciation. Human influence has also played a large role in changing spatial distributions of species and their natural functions and...
Words: 930 - Pages: 4
...factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming". Scientists actively work to understand past and future climate by using observations and theoretical models. A climate record — extending deep into the Earth's past — has been assembled, and continues to be built up, based on geological evidence from borehole temperature profiles, cores removed from deep accumulations of ice, floral and faunal records, glacial and periglacial processes, stable-isotope and other analyses of sediment layers, and records of past sea levels. More recent data are provided by the instrumental record. General circulation models, based on the physical sciences, are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change. Terminology The most general definition of climate change is a change in the statistical properties of the climate system when considered over long periods of time, regardless of cause. Accordingly, fluctuations over periods shorter than a few decades, such as El Niño, do not represent climate change. The term sometimes is used to refer specifically to climate change caused by human activity, as opposed to changes in climate that may have resulted as part of Earth's natural processes. In this sense, especially...
Words: 4109 - Pages: 17
...Describe the spatial characteristics of drumlins in Ireland and explain their relationship to the evolution of the last lowland ice sheets in Ireland. Drumlins are undoubtedly among the most intensively studied of all glacial landforms and have bee particularly widely used as ice-directional indicators. They frequently occur in ‘fields’ or ‘swarms’ in lowland areas where there was little obstruction to the passage of ice, or in piedmont zones where flow was radiative or dispersive. They are also occasionally found on the floors of glacial troughs. Many are ellipsoidal in form, some kilometres in length have been observed (Lemke 1958). Most possess a prominent stoss end with a trailing distal slope. It is generally agreed with the direction of the drumlin long axis reflects local direction of ice movement with the stoss end usually pointing up-glacier. The ice moulded or streamlined form appears to be produced by variations in stress levels at the base of the ice, although the precise mode of formation of the features is far from clear. The Kingscourt drumlins mentioned below gives a detailed account of the spatial characteristics and it’s internal components. ‘In addition to the regional ice flow trends displayed by their long axes, the overall shape of drumlins can provide information on former glacial dynamics, such as indications of basal ice pressure and rate and type of ice flow (Doornkamp and King 1971)’[1]. The recent work on drumlins has tended to concentrate...
Words: 1981 - Pages: 8
...Landforms Hydrologic Cycle The field of Hydrology is primarily concerned with how water falls from the atmosphere, to the Earth; rolls downhill via gravity eventually out to the ocean and then back up into the atmosphere starting all over again. Biological processes of animals and plants have evolved over millions of years to adapt to, and depend on, when the right amount of water is available (Lutgens & Tarbuck, 2014, p. 83). The hydrologic cycle goes through many processes; This continuous cycle of water releases up into the air, forms into a cloud, rains down to the Earth and then evaporates again, repeating this continuous process. Some amount of groundwater also releases back into the atmosphere through a process called transpiration which is evaporation of water from plants. The remaining water on the earth's surface is runoff, which finds its place in the lakes, streams and rivers, which eventually enters the oceans, starting the repetition of the hydrologic cycle. (Tallman, 2011). In Colorado, all of these concepts of the water cycle apply to the Colorado River Basin. Most of the storms that bring moisture into Colorado come from the Pacific Ocean and travel east through the atmosphere. Because of the altitude in the Rocky Mountains this moist air results in huge amounts of snow on the western slope. The Colorado River Basin is often called a snowmelt dominated system because this snow often sits in a deep snowpack until the spring when the temperature raises...
Words: 759 - Pages: 4
...happen and these flash floods will cut gullies and scarps into the landscape. Sand dunes are also a very common sight in a desert. These are created by winds that blow the sand around and eventually deposit them into different formations. Sand can travel many miles during the course of a year and can be devastating to anything in its path. Dunes can take on many shapes and characteristics. They include dome, crescentic, linear, star, parabolic, Seif, transverse, and reversing dunes. The shape and characteristic of the aforementioned dunes are dependent on the interaction with the wind. Silt and sand deposited by the wind is scientifically known as loess. The wind can also cause erosion. Wind erosion can occur through two processes, deflation and abrasion. Abrasion is the wearing away of solid surfaces as a direct result of the impact of high speed particles. One could think of it as sandblasting. This process works close to the ground. Deflation is the removing of sand, silt and loose clay by strong winds. Deflation can...
Words: 1186 - Pages: 5
...Unit 1 : Many Planets, One Earth Overview Astronomers have discovered dozens of planets orbiting other stars, and space probes have explored many parts of our solar system, but so far scientists have only discovered one place in the universe where conditions are suitable for complex life forms: Earth. In this unit, examine the unique characteristics that make our planet habitable and learn how these conditions were created. Surfaces of Mars, Moon, Venus, Earth. Source: NASA Sections: 1. Introduction 2. Many Planets, One Earth 3. Reading Geologic Records 4. Carbon Cycling and Earth's Climate 5. Testing the Thermostat: Snowball Earth 6. Atmospheric Oxygen 7. Early Life: Single-Celled Organisms 8. The Cambrian Explosion and the Diversification of Animals 9. The Age of Mammals 10. Further Reading Unit 1 : Many Planets, One Earth -1- www.learner.org 1. Introduction Earth's long history tells a story of constant environmental change and of close connections between physical and biological environments. It also demonstrates the robustness of life. Simple organisms first appeared on Earth some 3.8 billion years ago, and complex life forms emerged approximately 2 billion years ago. Life on Earth has endured through many intense stresses, including ice ages, warm episodes, high and low oxygen levels, mass extinctions, huge volcanic eruptions, and meteorite impacts. Untold numbers of species have come and gone, but life has survived even the most extreme fluxes. To...
Words: 8890 - Pages: 36
...Climate change From Wikipedia, the free encyclopedia For current and future climatological effects of human influences, see global warming. For the study of past climate change, see paleoclimatology. For temperatures on the longest time scales, see geologic temperature record. [pic] |Atmospheric sciences | |[pic] | |Aerology | |Atmospheric physics | |Atmospheric dynamics (category) | |Atmospheric chemistry (category) | |Meteorology | |Weather (category) · (portal) | |Tropical cyclone (category) | |Climatology | |Climate (category) | |Climate change (category) | |Global warming (category) · (portal) | |v · d · e | Climate change is a long-term change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average (e.g., more or fewer extreme weather events). Climate change may be limited to a specific region or may occur across the whole Earth. |Contents ...
Words: 3883 - Pages: 16
...landform, such as the Yellowstone Caldera volcano, is formed by specific processes and present distinct interactions with their surrounding environment. This as well as the rarity of it as a landform will be discussed in this report. 2.0 Table of contents: Title page: ………………………………………………………………...p1 1.0 Abstract: ......................................................................................p2 2.0 Table of contents: ………………………………….……………..…p2 3.0 Introduction: …………………………………………….………..…..p3 4.0 Structure and composition of Yellowstone volcano: ………….…p3-p4 5.0 Yellowstone volcano processes: ……………………………….….p4-p5 6.0 Yellowstone volcano interactions: …………………………….…...p5-p6 7.0 Rate of recurrence of caldera volcanoes as a landform: ……….p6 8.0 Conclusion: …………………………………………………………..p6 9.0 References: …………………………………………………………..p7 3.0 Introduction: The purpose of this report is to research and present reliable and detailed information on the Yellowstone caldera volcano. Through the examination of a range of published journal articles and internet sites on the topic of volcanic landforms, and more specifically on the Yellowstone caldera volcano, this report describes the Yellowstone caldera landform and goes into detail on four main topics of the volcano. These topics include the structure and composition of the selected volcano, its specific processes as a landform, how it interacts with other landforms or systems, and the...
Words: 2367 - Pages: 10
...Earthquakes I Earth’s composition Earth is a dense, stratified planet with many layers: core (inner and outer), mantle and crust Inner core: most dense material, solid iron and nickel Outer core: second most dense, liquid, iron and nickel Mantle: composed of oxygen, silicon, magnesium, aluminum Crust: composed of sodium and potassium rich silicate rocks Upper 100-350 km of upper mantle makes up asthenosphere: fluid layer due to heating from core Plate tectonics Earth’s uppermost layer, the lithosphere, broken up into 7 plates due to movement of asthenosphere underneath Plate tectonics- name for dynamic interactions of these plates Plate boundaries 3 types: divergent, covergent, and transform Divergent boundaries: tension from deep earth pulls two plates away from each other, allowing lava to upwell through the cracks and create new seafloor Covergent boundaries: two plates coming together as stress pushes plates toward each other- one plate forced under another in a subduction zone Transform boundaries: two plates slide past each other horizontally-frequent cause of destructive forces like earthquakes The nature of earthquakes Cause = abrupt movements on faults Fractures in earths lithosphere Normal fault- block above the fault has moved downward relative to the black below Reverse fault- upper block, above the fault plane, moves up and over the lower block (aka thrust fault) Right lateral strike slip fault- two blocks slide past one another Earths crustal...
Words: 11141 - Pages: 45
