1. Earth scientists are beginning to live what they once considered an impossible dream. They are establishing systems to monitor our entire planet continuously, from the outer fringes of the atmosphere to the deepest seabed. They even are beginning to track the grinding of rock upon rock that generates earthquakes. 2. They are linking communications systems to shunt these data to whomever can work them into useful knowledge. Often this now can be done in minutes instead of hours, days, or weeks. An unprecedented cooperation is developing among nations so that earth scientists will no longer look at our planet in the old, fragmented way. 3. These technological developments have brought humanity to the brink of great opportunities, said American Geophysical Union president John Orcutt at a meeting of the group last week in San Francisco. A few of many instances of such opportunities presented at the meeting illustrate this. 4. Scientists at the Scripps Institution of Oceanography in La Jolla, Calif., where Dr. Orcutt is deputy director, have developed a way to use the worldwide seismic observing network to image earthquake ruptures. Within 30 minutes or less, they can trace the entire crustal rupture that produces a quake anywhere in the world. This information is much more valuable than merely pinpointing the quake epicenter. This is important for tsunami warning systems in which you need to know a pathnot just the original locationof an earthquake, explains Scripps scientist Peter Shearer. 5. Meanwhile, in North America, the EarthScope project is establishing a continent-wide network of GPS locators, seismographs, and other instruments to study whats happening below the crust. 6. The network, which will cover the United States and reach into Canada and Mexico, is beginning to track the interaction of the two great crustal plates that respectively carry the Pacific Ocean and the continent. Its prime feature is an observatory in Parkfield, Calif., which has placed instruments nearly two miles deep into the Earth right up against the San Andreas fault to record every creep, rattle, and grind. The goal is to get into the heart of this earthquake machine and test scientists speculations as to how it works, says William Ellsworth, a geologist with the US Geological Survey in Menlo Park, Calif. 7. Networks of satellites already on orbit or soon to be launched are beginning to provide detailed observations of the workings of the atmosphere, ocean, and continental crust over the entire planet. These data are shared globally through an unprecedented cooperation among 58 nations called the Global Earth Observation System of Systems. 8. Orcutt noted that it will take high-volume high-speed communications to make the most of such sharing. Such a system, now under development, will shunt data a thousand times faster than current high speed broadband Internet links. Orcutt added that a strong commercial incentive exists to develop this system. It would allow movie studios, for example, to transmit a digital motion picture directly to theaters, where it could be shown in real time.
雅思阅读模拟题:new weapon to fight cancer
雅思阅读常见题型解析
雅思阅读高分技巧:猜测词义
雅思阅读备考手册:不能忽视题目说明
雅思阅读配对题解题小技巧
雅思阅读答题的8个常见关系词
如何应对雅思阅读长难句
雅思阅读高分方法:合理安排做题顺序
雅思阅读简答题的七大答题技巧
雅思阅读考试的解题步骤
雅思阅读高分策略:猜词义有技巧
雅思阅读备考高分建议三则
雅思阅读实用应试技巧介绍
雅思阅读高分技巧:单选题解题攻略
如何理解雅思阅读陌生词汇?
雅思阅读段落标题类7大介绍
细数雅思阅读高分必须掌握的技巧
雅思阅读判断题答题小技巧总结
雅思阅读备考须知事宜
解答雅思阅读题目需认真审题
雅思阅读技巧解析
提高雅思阅读效率的备考方法
雅思阅读分阶段备考计划分享
雅思阅读文章的结构和题型介绍
雅思阅读文章的展开方式
三类最常见的雅思阅读文章题材汇总
雅思阅读文章常见结构分析
如何提高雅思阅读效率?
雅思阅读判断题的四个答题技巧
雅思阅读文章来源介绍
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |