1. <sub id="zy88n"></sub>
        1. <blockquote id="zy88n"></blockquote>
          欧美黑人又大又粗xxxxx,人人爽久久久噜人人看,扒开双腿吃奶呻吟做受视频,中国少妇人妻xxxxx,2021国产在线视频,日韩福利片午夜免费观着,特黄aaaaaaa片免费视频,亚洲综合日韩av在线

          Scientists caught flatfooted by an increasingly "capricious" Magnetic North

          Source: Xinhua| 2019-01-13 14:24:01|Editor: xuxin
          Video PlayerClose

          WASHINGTON, Jan. 13 (Xinhua) -- The geomagnetic field makes lives possible by deflecting harmful radiation and keeping water and atmosphere in place. But now it's acting up, with increasingly unpredictable bipolar course change which renders compasses redundant.

          Unlike previous anomalies recorded at intervals averaging several hundred thousand years, recent movements of the magnetic poles have been alarmingly "erratic" -- frequent and faster -- from around 15 km per year before the mid-1990s to around 55 km right now, skittering away from Canada and towards Siberia, according to science journal Nature.

          The Earth's magnetic field is generated in the fluid outer core of sloshing molten iron by a self-exciting dynamo process. However, abrupt and irregular changes within the core has prompted scientists to update the World Magnetic Model, which describes the the planet's magnetic field and underlies all modern navigation, from the systems steering ships at sea to Google Maps on smartphones.

          The Clock is ticking right now for geomagnetists to release the updated model by the Jan. 15 deadline, the most recent of which issued in 2015 and supposed to last until 2020, according to Nature.

          Researchers from the U.S.-based National Oceanic and Atmospheric Administration and the British Geological Survey in Edinburgh has been checking annually to see if the model is able to capture all the variations in Earth's magnetic field.

          Starting 2018, the World Magnetic Model was not functioning well, its precision close to exceeding "the acceptable (safe) limit for navigational errors," Nature reported.

          Besides such errors, a disrupted geomagnetic field may also leave living beings on the planet vulnerable to an increased dosage of solar radiation.

          TOP STORIES
          EDITOR’S CHOICE
          MOST VIEWED
          EXPLORE XINHUANET
          010020070750000000000000011100001377403181
          主站蜘蛛池模板: 午夜在线观看免费线无码视频| 999zyz玖玖资源站永久| 18禁一区二区每日更新| 99亚洲精品| 亚洲中文字幕一区精品自| 免费啪啪网址| 亚洲精品岛国片在线观看| 国产麻豆精品在线观看| 欧美不卡视频一区二区三区| 久久综合伊人77777| 狠狠躁夜夜躁人人爽天天5| 国产又大又猛的三级视频| 国产人妻无码一区二区三区18| 国模gogo啪啪中国人体| 在线精品视频一区二区三区| 在线日韩日本国产亚洲| 国产精品久久久久久无码五月| 久久久久成人网站| 亚洲AV无码久久精品蜜桃播放| 日日麻批免费40分钟无码| 日本久久久久亚洲中字幕| 国产精品欧美日本韩免费一区二区三区不卡 | 国产乱码精品一区二三区| 亚洲国产精品午夜一区| 免费无遮挡毛片中文字幕| 国产午夜精品鲁丝片| 国产美女91| 亚洲成女人图区一区二区| 扒开末成年粉嫩的小缝视频| 动漫精品视频一区二区三区| 自拍视频在线观看一区| 久久久毛片免费全部播放| 99人中文字幕亚洲区三| 久久久久欧美精品| 最新国产网站| 久久尤物AV天堂日日综合| 国产小屁孩cao大人| 伦精品一区二区三区视频| 玖玖资源站亚洲最大成人网站| 69精品丰满人妻无码视频a片| 亚洲国产欧美国产综合一区|