From that information and information from the composition of isotopic carbon, we can infer changes in temperature for a over 100 thousand years.
Many geoscientists look at this plot and say, "Both temperature and CO decreased from the period 140 ka to 20 ka, and have rapidly and steadily increased in the last 20 ka." Students on the other hand could recognize the trend from 20ka to present but might have a difficult time recognizing the "trend" for 140-20 ka - they might say that the data is "all over the place" or "goes down and then up and then down for a little while and then up....".
Students and teachers could use general-purpose Web search engines, such as Google, MSN, or Yahoo! Does the site give copyright information for the material? How easy is it to search and retrieve the material? Students looking through the search results would have difficulty recognizing a good site from a bad or mediocre one.
Search, to find some of these free quality science sitesif they are willing to wade through the thousands of hits that result from a keyword search. And general search engines do not evaluate or annotate their content.
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12/26/2004 Sumatra quake and tsunami from IRIS ...about the quake models from IRIS NOAA: Tectonic plate movement, 200 million years ago to today USGS animations IRIS animations UC Santa Barbara multimedia visualization center another link to the UCSB multimedia visualization Center Exploring Earth visualizations Animations at RESGI gobookee geology animations Univ.
A more efficient, viable alternative is to search combinations of superb free Web directories/portals and free/fee-based vendor resources, with an emphasis on quality over quantity.