ice age on the earth

 hello, today is also a good day! don' t you think so? if NO, just hope tomrrow will be a better day!

  do you see the movies<Ice Age>?
  I like snow, but I can't image that the earth became a ice ball. can you?  So I think the earth in the ice age is the same in those movies, but not so many lovely animals.
   The Ice Age, which began about 2 million years ago, was very complex period characterized by a number of advances and with drawals of glacial ice. Most of the major glacial episodes occured during a division of the geologic time scale called  the pleistocene epoch. Perhaps the most convincing evidence for the occurrence of several glacial avdances during the Ice Age is the widespread existence of multiple layers of drift and un uniterrupted record of climate cycles perserved in seafloor sediments.
   Any theory that attempts to explain the cause of glacial ages must answer two basic questions:(1) What cause the onset of glacial condition? and (2) What cause the alternating glacial and interglacial stages that have been documented for the pleistocene epoch? Two of the many hypotheses for the cause of glacial ages involve (1) plate tectonics and (2) variation in Earth's orbit. Other factors that related to climate change during glacial ages include: change in atmospheric composition, variation in the amount of snnlight reflected by Earth's surface, and changes ocean circulation.
    Therefor, I will inrtoduce the glacier.
   
   
    A glacier is a thick mass of ice originating on land as a result of the compaction and recrystallization of snow, and it shows evidence of past and present flow. Today, vally or alpine glacier are found in mountain areas where they usually follow vallys that were originally accupied by steams. Ice sheets exist on a much larger scale, covering most of Greenland and America. In addition, covering some upland and plateaus are masses of glacial ice called ice caps. they occur in many places, including Iceland, and several of the large island in the Artic Ocean. Piedmont glacier occupy broad lowland at the bases of steep mountains and form when one or more alpine glaciers merge from the confining walls of mountain valleys.
   The average velocity of glacial movement is generally quite slow but varies considerably from one glacier to another. The advance of some glacier is characterized by periods of extremly rapid movement called surges.
   Any sediment of glacial origin is called drift. The two distinct types of glacial drift are (1)till, which is unsorted sediment deposyed directly by the ice; and (2) stratified drift, which is relatively well-sorted sediment laid down by the glacial meltwater. Also, landforms made of sratified drift.

   In addition to massive erosional and depositional work, other effects of Ice Age glacier include the forced migration of organism, changes in steam courses, formation of large proglacial lakes, adjustment of the crust by rebounding after the remorval of the immense load of ice, and climate changes caused by the existence of glaciers themselves. In the sea, the most far-reaching effect of the Ice Age was the worldwide change in the sea level that accompained each advance and retreat of the ice sheets.
    Today glaciers cover nearly 10 percent of Earth'land surface; however, in the recent geologic past, ice sheets were three times more extensive, covering vast areas with ice thousands of meters thick. So what make them disappeared? The global warming, or the pollutions, or some other thing? how do you think about it?
    we should know everything that on the earth to make our life better and live longer.

   

Earth's resources

 where does the clothes come from? where does the gus come from? where does the food come from?
  I thought that they are not made but be on the earth before. I'm wrong. some are made by human,and some are produced by the Earth. So what are the Earth's resources?  you will know by reading this blog.
   Resources are commonly divided into two broad categories_ renewable and nonrenewable. Renewable resources can be replenished over relatively short time spans. Example include natural fibers for clothing and tree for lumber. Nonrenewable resources form so slowly that, form a human standpoint, Earth contains fixed supplies. Example include fuels such as oil and coal, and metal such as copper and gold. A rapidly growing world population and the desire for an improved living standard are causing nonrenewable resources to become depleted at an increasing rate.
   Coal, petroleum, and natural gas, the fossil fuels of  our modern economy, are all associated with sedimentary rocks. Coal originates from large quantities of plant remain that assumulate in an oxygen-deficient environment, such as swamp. More than 70 percent of present-day coal usage is for the generation of electricity. Air pollution by the sulfur oxide gases that form from burning burning most types of coal is a significant environment problem.
   Oil and natural gas, which commonly occur together in the pore spaces of some sedimentary rocks, consist of various hydrocarbon compounds(compounds made of hydrogen and carbon mixed together). petroleum formation is associated with the accumulation of sediment in ocean areas that are rich in plants and animal remains that becaome buried and isolated in an oxygen-deficient environment. When conventional petroleum resources are no longer adequate, fuels derived from oil sand and oil shale may become subsititues. Presently, oil sands form the province of Alberta are a sinificant contributor to Canada's oil produce.
 

    Mineral resources are the endowment of useful mineral ultimately available commerially. Resources inlcude already idenfied deposits from which minerals can be extracted profitably, called reserves, as well as know deposits that are not yet economically or technologically recoverable. Deposits inferred to exist but not yet discovered are also considered mineral resources. The term ore is used to denote those useful metallic minerals that can be mined for a profit, as well as some nonmetallic minerals, such as fluorite and sulfur, that contain useful substances.
 




     How long can our remaining resources sustain the rising standard of living in today's countries and still provide for the growing needs of developing regions? How much environmental deterioration are we willing to accept in pursuit of resources? Can alternatives be found? If we want to live longer and longer, we should to understand our resources and their limits.

the study of landforms

   Before I talk about the landforms, you can watch the vedio. It can make you understand easily.

   We all familar with the magificent array of scenry on Earth's surface. It varies from the ice-covered to dry desert to teamy jungles. Geomorphology is the study of the varied landforms on the surface of the Earth, which I will talk about.
   Three primary influences affect the type of scenery that may be produced at a given point on Earth's surface. The first is the local geology_the type of rocks and structures that make up the land. The second is the local climate, cliamte varies with latitude; it is warm and wet the equator and cold and dry at the poles. Climate also varies as a result of atmospheric circulation. Time is the third major influence on landforms. Earth's contients are moved around on teconic plates, slowly changing position on the surface of globe. Accrodingly, the local climate will change with the time, and so well the landscapes that are formed. In a wod, Landforms are controlled by the local geology and climate,and by time.
   Before examing different geomorphologic environments, we must explore the role of gravity(mass wasting) and running water(the hydrologic cycle) in shaping the planet's surface.

    Mass wasting refers to the downslope movement of rock, regolith, and soil under the direct influence of gravity. In the evolution of the most landforms, mass wasting is the step that follows weathering. The combined effects of mass wasting and erosion by running water produce stream valleys.
   The hydrologic cycle describs the continuous interchange of water among the oceans, atmosphere, and continents. Powered by energy from the Sun, it is a global system in which the atmosphere provide the link between the oceans and continents. The processes involved the hydrologic cycle include precipitation, evaporation, infiltration(the movement of water into rocks or soils through cracks and pore spaces), runoff(water that flows over the land), and transpiration(the release of water wapor to the atmosphere by plants). Running water is the most important agent sculpting Earth's surface.
      Now the following will examine landforms.
      One of the most common landforms is valley. This feature is carried by small steams and rivers, and take a wide variety of forms_ from wide broad plains, such as the Grand Canyon of the Calorado River. The shape of a river valley depends on many factors such as the cliamte, the slope of the land surface, and the nature of soil or rock over which the river flows. The valley will change both in location and with time. In a mountain valley, a glacier can be likened to a river of ice. Like a river of water,it starts high in the mountains where snow collects and is changed into denser ice.
     As with the glacial envrionment, the desert environment is defined by climate. The scarcity of water that serves to define desert regions gives rise to unique landforms, although the basic principles of erosion, sediment transport, and diposition are the same in desert as anywhere on the continents.
       A desert is a part of the world that is literally deserted because of extremes in the environment. Although we may think of desert as being hot or sunny, desert regions are principally characterized by low rainfall. Most of the desert of the world are located in two belts adjacent to the tropic at 30°N and 30°S of the equator. These are regions that receive little rainfall owing to their location on the downflowing limits of atmosphere circulation cells. Desert conditions can also be caused by rainshadow effects.
   Coastlines are a dynamic interface between land and sea. They change position and form through time. On the time scale of single year, the coast at one location can vary from being barren of sediment to forming a sandy beach. Over shousands of years, shorelines have moved inland or regressed from land by several kilometers. The two main agents responsition along coasts are waves and tides. Tides are caused by the gravitational pull of the Sun and especially the Moon. Waves expend their energy by breaking, and the surf is an important agent of coastal erosion and transport.
    As we know, the Earth has many landforms,so I can't write all the forms in my blog. The surface of the Earth is changing slowly by the time, what the earth will be like after thousands of years? Can you image that? No, I can't.
   Hope you can feel the huge of the earth.
   

movement in space

 How do you think the radio? if you see that, you will know the Earth more.

 today I will talk about the Earth of the movement in space.
Three facts about the earth's motions are of vital consequence in the princeples of the earth science: first, that the earth turns on an axis, a motion always called ratation; second ., the axis of ratation is inclinned at a constant angle with respect to the plane of the earth's orbit, or plane of the ecliptic; third, that the orientation of the earth's axis in space with respect to the stars holds nearly constant.
   Earth's rotation is the rotation of the solid Earth around its own axis. The Earth rotates towards the east. As viewed from the North Star Polaris, the Earth turns counter-clockwise.
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. This is a different point than the Earth's North Magnetic Pole. The South Pole is the other point where the Earth's axis of rotation intersects its surface, in Antarctica.
The Earth rotates once in about 24 hours from the point of view of the sun and once every 23 hours 56 minutes and 4 seconds from the point of view of the stars (see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation. Atomic clocks show that a modern day is longer by about 17 milliseconds than a century ago, slowly increasing the rate at which UTC is adjusted by leap second

In astronomy, the Earth's orbit is the motion of the Earth around the Sun, from an average distance of approximately 150 million kilometers away. A complete orbit of the earth around the Sun occurs every 365.256363 mean solar days (1 sidereal year)^. This motion gives an apparent movement of the Sun with respect to the stars at a rate of about 1°/day (or a Sun or Moon diameter every 12 hours) eastward, as seen from Earth. On average it takes 24 hours—a solar day—for Earth to complete a full rotation about its axis relative to the Sun so that the Sun returns to the meridian. The orbital speed of the Earth around the Sun averages about 30 km/s (108,000 km/h), which is fast enough to cover the planet's diameter (about 12,700 km) in seven minutes, and the distance to the Moon of 384,000 km in four hours.
 So this blog is difficult to write.I don't know the movement of the earth very well. But I want to know how can the earth move in the sapce .
 The movement of the earth creat the time and the season,so we can see the flower or the snow by diffierent seasons,and we can live by death and bron. I think is magical.
 











 

Earth system reservior

    hello everyone! we have been in a new year now, and I hope that this year will be a good year for you guys!
   tody I will talk about the Earth system reservior.
    The physcial environment is divided into three major parts: the water portion of our planet, the hydrosphere; Earth's gaseous envelope, the atmosphere; and,the solid Earth, or geosphere.moreover, the biophere, which is the totality of all plant and animal life on our planet.Thus, Earth can be thought of as consisting of four major spheres: the hydrosphere, atmosphere, geosphere,and biosphere. in addition, I will also introduction the fifth focus:the anthrosphere, which gives us the opportunity to consider resource use in built and technological envronments, as well as human influences on other parts of the Earh system.
    The hydrosphere is a dynamic mass of water that is continually on the move, evaporating from the oceans to the atmosphere, precipitating to the land, and running back to the ocean again. The global ocean is certainly the most prominent feature of hydrosphere, blanking nearly 71 percent of the Earth's surface to an average depth of about 3800 meters. It accounts for about 97 percent of Earth's water. However the hydrosphere also includes the fresh water found underground and in steams, lakes, and glaciers.
  
     
  
  



The atmosphere is the mixture of gases--predominantly nitrogen, oxygen, argon, carbon dioxide,and water vapor--that surrounds Earth.The atmosphere seems very thick to us, but in the context of the whole planet it is a very,very thin layer. The atmosphere  provides many crucial sercices, such as protecting life from damaging solar radiation, and being the reservior for oxygen and carbon dioxide, two gases that are essential for the biosphere. The outermost layer of the atmosphere is, in effect, the boundary of the Earth system, seperate us from our surrounding in space.
    The geosphere is the solid Earth, composed principally of rock and regolith. the surface of the geosphere is a particularly interesting and dynamic place, where energy that comes into the Earth system from outside sources meets energy that comes from within the planet. These forces combine and compete to build up and wear down the materials at Earth's surface, creating the enormous diversity of landscapes around us. the dynamic nature of the geosphere can also be hazardous for human interests, by way of process such as landslides, earthquakes, and volcanic eruptions.
    The biosphere includes all life on Earth. ocean life is concentrated in the sunlit surface water of the sea. Most life on land is also concentrated near the surface, with tree roots and burrowing animals reaching a few meters underground and flying insects and birds reaching a kilometer or so into the atmosphere. A surprising variety of life forms are also adapted to extreme environments.On land, some bacteria thrive in rocks as deep as 4 kilometers and in boiling hot spring. Moreover, air currents an carry microorganisms many kilometers into the atmosphere.
    The anthroposphere is the "human sphere". It comprises people and their interests, as well as huaman impacts on the natural Earth system. The anthroposphere is the part of the natural system that has been modified by humans, for human purposes or as a result of human activities. Another term that applies to the anthroposphere is technosphere, which refers specifically to technology, machines, and the built environment.
    The Earth we live on have many  systems. The life can be live on the planet is beacsuse that the Earth is the right distance from the Sun--not too near, and not too far.
    On the Earth, we can change the enviroment. When the pollution is large, the systems will be changed. There are now so many of us that we are changing Earth  just by being alive and going about our business.
    So if we want to live on the Earth longer, what we should to do for us, or for the Earth?