摘要
据前人统计，厄尔尼诺出现于地球自转速度急剧变慢的第二年。造成这种现象的主因，是地球间歇性不对称膨胀，引起自转速度几年一次的准周期性急剧变慢。在该时期南北半球岩石圈产生强烈的离开赤道的体力，使赤道地区发生东西向张性断裂活动。位于阻力较小的软流层之上的太平洋岩石圈，不仅规模大、动力强，而且存在着东太平洋海隆薄弱带，并与秘鲁海沟应变空间毗邻，故现今太平洋东部赤道地区的东西向张性断裂最为发育，形成规模宏大的卡内基断裂带和加拉帕戈斯断裂带。它们活动促使海底的岩浆和热水喷溢，导致厄尔尼诺的海水升温多从秘鲁－厄尔多尔沿岸开始。地球自转速度变慢过程中，赤道地区的大气和海水获得较多的向东角动量，造成该地区的信风和向西流动洋流减弱、东太平洋冷水上翻涌升流衰缓，加速赤道东太平流海域温度变暖，助长厄尔尼诺的形成。全球大气角动量的季节性变化，也引起地球自转速度冬季慢夏季快的周年项变化，使厄尔尼诺年增温盛期一般出现于年末前后。
As predecessors’ statistics, El Nio comes out in the second year when the rotation speed of the earth changed sudden slowly. Main cause of formed this phenomena is that the earth expands intermittently and unsymmetrically and the rotation speed of the earth sets off a paraperiodic and sudden slow one by several years. During the time the lithosphere of south north semisphere produces a strong sphere strength setting off the equator and makes the equatoric area a series of east west direction tension fractures. The Pacific lithosphere over the flowage bed with the smaller resistance is not only with a big scope and strong motive force, but also with one weak zone of the east Pacific oceanic rise, which borders on the strain space of Peru oceanic groove, so the east west direction tension fractures develop very much in today’s east Pacific equatoric area and formed the Kanyki and Canapogos fractures with a gigantic scope. Their activity gives magma and heat water extrusion and overflowing in sea floor and leads to El Nio phenomena of sea water temperature raising along Peru Ecuador coast. During the rotation speed slow of the earth the atmosphere and sea water in the equatoric area aquire more east direction angular momentum and makes the area the weak trade wind and oceanic current onto the west flowing and slow feeble upwelling oceanic surging current of the east Pacific cool water and quicken temperature raising of the east Pacific current in equatoric sea area as well as support El Nio formation. Seasonal change of the atmosphere angular momentum of the earth gives also an anniversary change of the rotation speed of the earth offering as winter slow and summer fast and makes the height present of temperature raising in El Nio year normally round the year end.
出处
《化工矿产地质》
CAS
1998年第3期199-204,共6页
Geology of Chemical Minerals
关键词
厄尔尼诺
地球自转
赤道地区
东太平洋
张性断裂
El Nio, the rotation of the earth, the equatoric area, east Pacific, tension fracture
