世界上最长的海底山脉_地理世界之最

编者:地理学者 来源:最有料 时间:2014-12-09 10:05 最签:最长 浏览:

中洋脊是伴有地震和火山活动的巨大海底山系。它纵贯太平洋、印度洋、大西洋和北冰洋,彼此相连,总长约8万公里,为地球上最长最大的山系,换句话说中洋脊是世界上最长的海底山

  中洋脊是伴有地震和火山活动的巨大海底山系。它纵贯太平洋、印度洋、大西洋和北冰洋,彼此相连,总长约8万公里,为地球上最长最大的山系,换句话说中洋脊是世界上最长的海底山脉。

  在板块构造模式中,大洋中脊顶部标出了海底扩张轴线,属分离型板块边界。它既是巨大的海底地形单元,也是最重要的海底构造单元之一。中洋脊又名大洋中脊、中隆或中央海岭。隆起于洋底中部,并贯穿整个世界大洋,为地球上最长、最宽的环球性洋中山系。在太平洋,其位置偏东,称东太平洋海隆(海岭)。大西洋中脊呈“S”形,与两岸近于平行,向北可延伸至北冰洋。

  

世界上最长的海底山脉

 

  印度洋中脊分3支,呈“入”字形。三大洋的中脊在南半球互相连接,总长达8万公里,面积约1.2亿公里2,占世界海洋总面积的1/3。其脊部通常高出两侧洋盆底部1~3公里,脊顶水深多为2~3公里,少数山峰出露于海面形成岛屿,如冰岛、亚速尔群岛等。洋中脊常被一系列与其正交或斜交的断裂带错开(称断错带),其中大西洋中脊在赤道附近的罗曼什断带(Romanchegap),东西错动距离达1000多公里。沿断裂带有狭长的沟槽、海脊和崖壁。在大西洋和印度海中脊的轴部,一般有深约1~3公里、呈纵向分布的中央断裂谷地。

  洋中脊是现代地壳最活动的地带,经常发生火山活动、岩浆上升和地震,水平断裂(转换断层)广布。根据海底扩张和板块构造学说,洋中脊是洋底扩张的中心和新地壳产生的地带。热地幔物质(熔融岩浆)沿脊轴不断上升,凝固成以超基性和基性岩组成的新洋壳,并不断向两侧扩张推移。扩张的半速度(即每边速度)多为1~5厘米/年。

  Mid ocean ridge is a great Cordillera with earthquake and volcano activities. It runs through the Pacific Ocean, India ocean, the Atlantic ocean and Arctic Ocean,connected to each other, a total length of 80000 km, for Earth's longest and biggestmountain ridge, in other words, is the world's Longest Undersea mountains.

  In the tectonic pattern plate, top of the ridge in the ocean marked the seafloor spreading axis, the separation plate boundary. It is not only a huge submarinelandform unit, one of the most important submarine tectonic unit. Mid ocean ridge,also known as the mid ocean ridge in the central ridge augmentation or. On the bottom of the ocean in the central uplift, and throughout the world ocean on earth, the longest, the most wide Global Ocean Department of Zhongshan. In the Pacific, its location east, said the East Pacific Rise (ridge). The Atlantic ridge was "S" shape,parallel and cross strait near, can be extended to the Arctic Ocean to the north.

  The world's Longest Undersea mountains

  India ridge is divided into 3 branches, is "into the" font. The ridge in the three oceansare connected to each other in the southern hemisphere, a total length of 80000 kilometers, an area of about 120000000 km 2, accounting for the total area of the oceans of the world 1/3. The ridge is usually high out of both sides of ocean bottom 1~ 3 km, ridge top depth is 2 ~ 3 km, a few peaks exposed on the surface of the seaislands are formed, such as Iceland, the Azores etc.. Mid ocean ridges are oftenstaggered breaking a series of orthogonal or oblique band (called fault zone), of whichthe Atlantic ridge near the equator Romansh fault zone (Romanchegap), the wrong things moving distance of 1000 kilometers. Along the fault with narrow grooves, ridges and cliffs. In the Atlantic and India sea shaft ridge, generally have a depth of about 1to 3 kilometers, is the central fault valleys of the vertical distribution of.

  A mid ocean ridge is the most modern crustal activity zone, often occurring volcanic activity, magma ascent and earthquake, horizontal fracture (transform fault) wide cloth. According to the seafloor spreading and plate tectonics, mid ocean ridge is the sea floor spreading center and new crust to produce area. Hot mantle materials(molten lava) along the ridge axis rising, solidified into a new ocean crust to ultrabasicand mafic composition, and to continue to expand on both sides of the passage. Halfspeed expansion (i.e., each edge speed) ranged from 1 to 5 cm / year.

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