麻豆淫院

(麻豆淫院) 鈥擡arth scientist Dennis Darby is arguing in a Letter article published in Nature Geoscience, that perennial sea ice existed as far back as 44 million years ago. He's developed a technique for dating perennial sea ice that involved analyzing grains of iron oxides found in ice core samples that he claims, date back 26 million more years that current estimates project. He suggests that such grain samples could only be where they are if sea ice existed year round. Catherine Stickley, offers a News & Views Piece in the same journal edition, suggesting that Darby's work could help to more accurately forecast what conditions might be like over the next century as sea ice melts completely every summer.

Earth scientists and climatologists alike are working diligently to predict what life might look like here on planet Earth after polar ice begins melting completely every summer. Clearly, ocean levels will rise, but what other impacts might we expect? Darby doesn't make any predictions, but his work offers a possible peek into the past when the planet underwent a similar transformation.

Our planet has gone through several warm and cold spells, and as it did so, the amount of ice present increased and decreased. Some of the warm spells, scientists believe, were so warm that polar ice melted completely during the warm months. In this new effort, Darby has found a new way to date when it was that ice was maintained at the poles all year round. He's been examining ice core samples taken by the Integrated Drilling Program in the Arctic. He's found grains of iron oxides in the ice, which date back to approximately 44 million years ago. But this conflicts with conventional science, which has found evidence (debris and fossil evidence) for perennial ice only as far back as 18 million years ago.

Darby argues that the grains he's found could only have made their way to where they were found (because of the long duration of the trip) if ice existed year round. Thus, the evidence suggests that perennial ice might not have developed as recently as thought. But if this is true, it causes a bit of a conundrum, as other evidence suggests that worldwide air temperatures should have been warm enough to cause the poles to melt in the summer. If they did not, there had to have been some other, mysterious cause. This could have serious implications for the planet today. Is it possible that predicted temperature rises the world over due to green house gases may not cause the poles to melt in the warm months in the timeframe predicted, due to some unknown cause? And if not, when might it happen instead? Now it appears, scientists may not have the answers.

漏 2014 麻豆淫院