在中国的西北部，沙漠条件保存了长城最偏远的部分。科学家们正在探索着2000年前的建筑材料，以寻找该地区过去气候的迹象。
isotopes
Posted inScience Updates
How Great was the “Great Oxidation Event”?
Geochemical sleuthing amid acid mine runoff suggests that scientists should rethink an isotope signal long taken to indicate low levels of atmospheric oxygen in Earth’s deep past.
Posted inNews
Carbon Cycles Through Plants More Quickly Than Expected
A radioactive isotope produced by nuclear weapons reveals that plants take up more carbon—but hold on to it for less time—than current climate models suggest.
Posted inResearch Spotlights
Radioactive Isotopes Trace Hidden Arctic Currents
Tracing anthropogenic radionuclides shows researchers how water from the Atlantic flows into and mingles with Arctic currents.
Posted inNews
Toxic Metal on the Rise in the Baltic Sea
Postwar reconstruction is likely the cause of elevated thallium levels, but low-oxygen, high-sulfide conditions keep the material, which is extremely dangerous to mammalian health, from moving into the human food chain.
Posted inResearch Spotlights
Mantle Heat May Have Boosted Earth’s Crust 3 Billion Years Ago
Information from igneous zircon molecules gives researchers new insight into the workings of inner Earth.
Posted inScience Updates
Submarine Avalanche Deposits Hold Clues to Past Earthquakes
Scientists are making progress on illuminating how undersea sedimentary deposits called turbidites form and on reconstructing the complex histories they record. But it’s not an easy task.
Posted inNews
Hiroshima Fallout May Offer a Glimpse of the Early Solar System
Bits of glass called Hiroshimaites may have formed by processes similar to those that formed the Sun and the planets.
Posted inEditors' Highlights
What Happens to Nutrients After They Leave Agricultural Fields?
To better quantify the fate of nutrients after they are released from agricultural fields, scientists examine storage and nitrate export regimes in agricultural hydrology systems.
Posted inResearch Spotlights
Metals Could Reveal Corals’ Past Lives
Examining the role of stable metal isotopes in biological activities such as photosynthesis provides a promising new avenue of research into how coral responds to environmental stressors.