University of Liverpool data indicates that the Earth’s inner core originated 1-1.5 billion years ago as it solidified from the molten iron outer core. Credit: Kay Lancaster, Department of Earth, Ocean and Ecological Sciences New data from the University of Liverpool reveals that the Earth’s...
(2016) Earth's air pressure 2.7 billion years ago constrained to less than half of modern levels. Nature Geoscience: DOI: 10.1038/NGEO2713.Som, S. M., Buick, R., Hagadorn, J. W., et al. (2016). Earth's air pressure 2.7 billion years ago constrained to less than half of modern ...
83. About 2 billion years ago, the oxygen content in the earth's atmosphere began to increase dramatically. This increase in atmospheric oxygen had important implications for the evolution of life on the planet. Which of the following is/are a result of this oxygen increase?(①)(a) The ...
6 billion years old. However, the mountains, valleys(山谷), hills,rivers, deserts and forests we see today are much younger than that.For example, Mount Qomolangm a is about 60 million years old and the Amazon rainforest is only 10 million years old. The youngest se a in the world ...
Certainly the processes of internal convection, segregation of minerals by partial melting and recrystallization, and basaltic volcanism were operating more vigorously in the first billion years of Earth’s history, when the planet’s interior was much hotter than it is today; nevertheless, how the ...
Astrophysicists from theUniversity of Toronto (U of T)have shed light on the mystery of why Earth’s day, which was gradually increasing due to the moon’s tidal influence, paused in its lengthening for over a billion years. Their research indicates that from around two ...
Transient marine bottom water oxygenation on continental shelves by 2.65 billion years ago Oxygenated bottom water existed transiently on continental shelves with O2penetrating into underlying marine sediments by about 2.65 billion years ago, according to a study of thallium isotopes in Archaean shales. ...
EversinceEarthformedroughly4.5billionyearsago,itsclimatehasgonethroughanumberofincrediblechanges.AllyouhavetodoislookatimagesoftheJurassicPeriod(侏罗纪时期)toknowthatatonetime,muchofourplanetwascoveredinextremelyhotandhumidjungle.Skipaheadacouplemillionyearsandyougettoaniceageevent,whenglobaltemperatureexperiencedahuge...
In fact, all of the iron-60 that may have been native to Earth and on the planet through the more than 4 billion years of Earth’s history, should already be gone. The iron isotope has a half-life of just 2.6 million years.
解析:题干大意:科学家估计,地壳在30亿年前就开始变化。文章第三段第二句提到:They’ve found new evidence suggesting that Earth’s crust started shifting atleast 3.8 billion years ago.他们发现新证据——地壳至少在38亿年前就开始变化。题干所述把文章信息的年份缩短了,故答案选B。反馈 收藏 ...