alpine glacier_alpine glaciers

alpine glacier_alpine glaciers _alpine glaciers

       alpine glacier的今日更新不仅仅是技术上的更新，更是人们生活方式的改变。今天，我将和大家探讨关于alpine glacier的今日更新，让我们一起探讨它对我们生活的影响。

1.参考文献

2.跪求冰川时期的一些英文资料~

参考文献

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跪求冰川时期的一些英文资料~

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       头部装备需要头灯、备用灯泡和电池、带侧盖的雪镜、滑雪护目镜、棒球帽或面甲、羊毛帽及轻便型和厚重型巴拉克拉法帽。准备一条合成材质的大手帕以保护脖子。另外还需要四副不同的手套：可用在其他手套里面的轻便合成材质手套、户外羊毛手套、防水手套及户外长手套。

       登山装备

       在登山鞋底部扣上卡式冰爪。带好备用冰爪以防损坏。准备适合全副衣装的高海拔攀登吊带一副、带锁钩环和固定钩环各三个、左右上升器各一个、保护器一个、普鲁士绳结（也可以使用长度为12米、直径为6毫米的贝纶绳制作普鲁士绳结）。攀爬洛子峰和冲击峰顶时，冰斧（配有专门设计的腕带）也必不可少。冰斧长度应根据自己的身高进行选择——如果身高不超过1米64，应选择长度为60厘米的冰斧；如果身高在1米64至1米 85之间，则应选择长度为65厘米的冰斧。冰川绳也很重要。有关“绳结制作”和冰川绳索用法的详细信息，请查看Get Outdoors网站上的冰川行走入门(Glacier Travel:Fundamentals)。

       钩环和保护器

       钩环和保护器

       营地物品

       在每个营地中，都需要两个高质量的羽绒睡袋（户外徒步型，至少能抵御零下20至40摄氏度的低温）、至少两个自充气式防潮垫和一个保温垫；在有些营地中，将两块垫子叠起来用可能更舒服一些。

       您还需要准备几顶帐篷：在珠峰大本营时需要一顶大帐篷，海拔越高，所需的帐篷必须越小、越轻、质量越好。指南针或小型GPS设备能帮助您找到珠峰峰顶的位置。携带两个钛质炉头，确保在需要时至少有一个能正常使用（可以加快做饭速度）。至于炊具和餐具，您需要二到三只轻便的锅子（带锅盖）、塑料杯、热水壶、勺子、刀（如莱泽曼(Leatherman)刀具）以及几块隔热垫。

       多准备一些火柴和打火机，取暖和做饭都少不了它们。但要确保打火机质量过硬，在海拔较高地区也能正常使用。准备一架化学净水器能减少您烧水的麻烦，但您需要额外携带净水材料。

       准备两个塑料水壶，再准备一个供小便用的大口壶。有条件的户外运动旅行社会提供煤气和氧气。可使用大容量远足包或登山背包来装运您的装备（您或许还需要一只较小的可随身携带的背包）。背包上必须有可供悬挂冰斧和其他登山装备的挂钩。别忘了在背包里放上防晒霜、润唇膏和一小套个人急救用品。

       电子装备

       The Big Chill

       by Kirk A. Maasch

       During the past billion years, the Earth's climate has fluctuated between warm periods - sometimes even completely ice-free - and cold periods, when glaciers scoured the continents. The cold periods - or ice ages - are times when the entire Earth experiences notably colder climatic conditions. During an ice age, the polar regions are cold, there are large differences in temperature from the equator to the pole, and large, continental-size glaciers can cover enormous regions of the earth.

       Ever since the Pre-Cambrian (600 million years ago), ice ages have occurred at widely spaced intervals of geologic time - approximately 200 million years - lasting for millions, or even tens of millions of years. For the Cenozoic period, which began about 70 million years ago and continues today, evidence derived from marine sediments provide a detailed, and fairly continuous, record for climate change. This record indicates decreasing deep-water temperature, along with the build-up of continental ice sheets. Much of this deep-water cooling occurred in three major steps about 36, 15 and 3 million years ago - the most recent of which continues today. During the present ice age, glaciers have advanced and retreated over 20 times, often blanketing North America with ice. Our climate today is actually a warm interval between these many periods of glaciation. The most recent period of glaciation, which many people think of as the "Ice Age", was at its height approximately 20,000 years ago.

       Although the exact causes for ice ages, and the glacial cycles within them, have not been proven, they are most likely the result of a complicated dynamic interaction between such things as solar output, distance of the Earth from the sun, position and height of the continents, ocean circulation, and the composition of the atmosphere.

       Climatic Cooling from 60 million years ago to present day

       Between 52 and 57 million years ago, the Earth was relatively warm. Tropical conditions actually extended all the way into the mid-latitudes (around northern Spain or the central United States for example), polar regions experienced temperate climates, and the difference in temperature between the equator and pole was much smaller than it is today. Indeed it was so warm that trees grew in both the Arctic and Antarctic, and alligators lived in Ellesmere Island at 78 degrees North.

       But this warm period, called the Eocene, was followed by a long cooling trend. Between 52 and 36 million years ago, ice caps developed in East Antarctica, reaching down to sea level in some places. Close to Antarctica, the temperature of the water near the surface dropped to between 5 and 8 degrees Celsius. Between 36 and 20 million years ago the earth experienced the first of three major cooling steps. At this time a continental-scale temperate ice sheet emerged in East Antarctica. Meanwhile, in North America, the mean annual air temperature dropped by approximately 12 degrees Celsius.

       Between 20 and 16 million years ago, there was a brief respite from the big chill, but this was followed by a second major cooling period so intense that by 7 million years ago southeastern Greenland was completely covered with glaciers, and by 5-6 million years ago, the glaciers were creeping into Scandinavia and the northern Pacific region. The Earth was once more released from the grip of the big chill between 5 and 3 million years ago, when the sea was much warmer around North America and the Antarctic than it is today. Warm-weather plants grew in Northern Europe where today they cannot survive, and trees grew in Iceland, Greenland, and Canada as far north as 82 degrees North.

       We are still in the midst of the third major cooling period that began around 3 million years ago, and its effect can be seen around the world, perhaps even in the development of our own species. Around 2 and a half million years ago, tundra-like conditions took over north-central Europe. Soon thereafter, the once-humid environment of Central China was replaced by harsh continental steppe. And in sub-Saharan Africa, arid and open grasslands expanded, replacing more wooded, wetter environments. Many paleontologists believe that this environmental change is linked to the evolution of humankind.

       Possible Explanations for the Past 60 Million Years of Cooling

       Climate change on ultra-long time scales (tens of millions of years) are more than likely connected to plate tectonics. Plate motions lead to cycles of ocean basin growth and destruction, known as Wilson cycles, involving continental rifting, seafloor-spreading, subduction, and collision. Several explanations of the latest cooling trend that involve a climate-tectonic connection are summarized below.

       Geographic Distribution and Size of Continents

       Through the course of a Wilson cycle continents collide and split apart, mountains are uplifted and eroded, and ocean basins open and close. The re-distribution and changing size and elevation of continental land masses may have caused climate change on long time scales. Computer climate models have shown that the climate is very sensitive to changing geography. It is unlikely, however, that these large variations in the Earth's geography were the primary cause of the latest long-term cooling trend as they fail to decrease temperatures on a global scale.

       Likewise, changing topography cannot, by itself, explain this cooling trend. Computer model experiments performed to test the climate's sensitivity to mountains and high plateaus show that plateau uplift in Tibet and western North America has a small effect on global temperature but cannot explain the magnitude of the cooling trend. Plateau uplift does, however, have a significant impact on climate, including the diversion of North Hemisphere westerly winds and intensification of monsoonal circulation.

       Geometry of Ocean Basins

       Another theory explaining these changes in climate involves the opening and closing of gateways for the flow of ocean currents. This theory suggests that the redistribution of heat on the planet by changing ocean circulation can isolate polar regions, cause the growth of ice sheets and sea ice, and increase temperature differences between the equator and the poles.

       Ocean modeling experiments suggest that the ocean could not have carried enough heat to the poles to maintain the early warm climates. But atmospheric climate modeling experiments show that even if the ocean did transport enough heat up to the coast of Antarctica to maintain sea surface temperatures at 10 to 15 degrees Celsius, the interior conditions would still be much colder - and this is contrary to the geologic record. It is possible, however, that changes in heat transport caused by variations in ocean gateways may have played a significant role in cooling trends over the last 60 million years, and, in particular, may help explain some of the relatively sudden cooling events.

       Atmospheric Carbon Dioxide

       Changes in the concentration of carbon dioxide in the atmosphere are a strong candidate to explain the overall pattern of climatic change. Carbon dioxide influences the mean global temperature through the greenhouse effect. The globally averaged surface temperature for the Earth is approximately 15 degrees Celsius, and this is due largely to the greenhouse effect. Solar radiation entering earth's atmosphere is predominantly short wave, while heat radiated from the Earth's surface is long wave. Water vapor, carbon dioxide, methane, and other trace gases in the Earth's atmosphere absorb this long wave radiation. Because the Earth does not allow this long wave radiation to leave, the solar energy is trapped and the net effect is to warm the Earth. If not for the presence of an atmosphere, the surface temperature on earth would be well below the freezing point of water.

       Through a million year period, the average amount of carbon dioxide in the atmosphere is affected by four fluxes: flux of carbon due to (1) metamorphic degassing, (2) weathering of organic carbon, (3) weathering of silicates, (4) burial of organic carbon. Degassing reactions associated with volcanic activity and the combining of organic carbon with oxygen release carbon dioxide into the atmosphere. Conversely, the burial of organic matter removes carbon dioxide from the atmosphere.

       Plate collisions disrupt these carbon fluxes in a variety of ways, some tending to elevate and some tending to lower the atmospheric carbon dioxide level. It has been suggested that the Eocene, the early warm trend 55 million years ago, was caused by elevated atmospheric carbon dioxide and that a subsequent decrease in atmospheric carbon dioxide led to the cooling trend over the past 52 million years. One mechanism proposed as a cause of this decrease in carbon dioxide is that mountain uplift lead to enhanced weathering of silicate rocks, and thus removal of carbon dioxide from the atmosphere.

       In addition, the collision of India and Asia led to the uplift of the Tibetan Plateau and the Himalayas. While topography may not be enough to explain the cooling trends, another mechanism may account for changing climate. The uplift may have caused both an increase in the global rate of chemical erosion, as well as erode fresh minerals that are rapidly transported to lower elevations, which are warmer and moister and allow chemical weathering to happen more efficiently. Through these mechanisms, then, it has been hypothesized that the tectonically driven uplift of the Tibetan Plateau and the Himalayas is the prime cause of the post-Eocene cooling trend.

       Kirk A. Maasch is a professor at the University of Maine, in the Department of Geological Sciences.

       好了，关于“alpine glacier”的话题就讲到这里了。希望大家能够通过我的讲解对“alpine glacier”有更全面、深入的了解，并且能够在今后的工作中更好地运用所学知识。