问题 问答题 简答题

说明各种海面高度变化研究理论

答案

参考答案:

(1)大洋容积的变化:如果大洋水体为一常量的话,海洋容积的变化自然会引起海岸地区的海面变动。

(2)海水体积的变化:当全球性的冰盖形成时,将大量水体固着在大陆上,可能数万年不回归海洋。海洋失去了水量,海水体积发生变化,将引起海面降低。

(3)天文因素引起海面变化:认为天文因子影响地球冰期与间冰期的转变。

(4)冰冻型海面变化:由于全球性的气候变化,导致大陆冰盖发育和山地冰川的扩展,海水体积大为减少,引起冰冻型海面升降。

(5)地动型海面变化:地球内外力运动改变了洋盆容积,形成地动型海面变化,也称构造型海面升降运动。不论是沉积物的填充,还是洋底构造的上升或下沉,都会引起大洋容积的变化,从而导致海面变化。

(6)大地水准面变化引起的海面变化:大洋水体和其他物体一样,都受到地球重力的影响。重力也要控制大洋水面的分布,引起海面变化。

(7)地壳回弹作用引起的海面变化:当地球表面在冰盖的重压下,地壳往往会发生下沉。一旦冰盖融化,从前下沉的地区会终止下沉,甚至会出现地壳重新升起,直至达到一个新的平衡时才停顿,由于冰川的消长比较明显,在地质学上称为地壳回弹现象。

(8)海水的热膨胀引起的海面变化:大洋表层的海水吸收大气的热量向深部输送,其过程是表层混合层——温跃层——大洋底层。输送到混合层需3-6年,温跃层内50-250年,到达大洋深处需500-1000年。

(9)全球海面升起特征的理论性假说:根据克拉克的模拟计算,把全球海洋划分为六大区,每个区有自己特征的海面变化曲线,而各区之间的海面曲线都不相同。

阅读理解

阅读理解

      The first harvest means the death of the crops as grain is gathered, and the thanksgiving of the people

to the goddesses who provided them with life sustaining grains.

     Late July and early August mark the middle of summer and the beginning of the harvest season.

"Famine (饥荒) was common during July as the previous years' harvest supplies were almost totally used UP. Harvesting grains in August ensured the continuance of life and was recognized by many cultures as a

time of thanksgiving.

      In ancient Rome the grain goddess Ceres was honored on the first harvest called Ceresalia in her

honor. Our modern word cereal comes from her name. Other goddesses celebrated at the first harvest

were Demeter, Persephone, Venus and the Corn Mother. Many native American tribes honor the Corn

Grandmother during the Festival of Green Corn. It was held during the full moon when the corn was

ready to be harvested. The celebration lasted for several days and was a time to be thankful and a time

of forgiveness.

     Lughnasadh was a happy time regarded as the first of three harvest festivals. Lughnasadh honors the

god Lugh, and his foster-mother Taillte who died while clearing the fields of Ireland for agriculture. In

Old Irish "Lunasa" means "August". The Celts celebrate this day from sunset of August 1 to sunset on

August 2 as the wake of Lugh, the Sun-King whose light began to decline after the summer solstice (夏至). At this time oaths ( 誓言) were taken and contracts were signed.

     This day was known to the Saxons as Lammas, or loaf-mass, a time when grains were harvested and

baked into bread. The grain was harvested, giving its life so that people might live. The grain was made

into bread, and the bread was symbolic of the gods. Christians later adopted this holiday as a day when

bread, made from the first fruits of the harvest, was brought to the church to be blessed.

     August is a time to reflect on the past year, on things that have come to fruition and things that failed.

A time to let go of regrets and say farewell to things that have passed and preserve all the fruits that have

been gathered to hold onto for future memories.

1. The passage should be entitled ______.

A. August Harvest Festivals            

B. August Tradition

C. Gathering Grain                    

D. Special August Time

2. What was the significance of harvesting grains in August?

A. It welcomed the death of the crops.  

B. It provided the chance of thanksgiving.

C. It guaranteed the continuance of life.    

D. It marked the middle of summer.

3. Which of the following is NOT a close relationship according to the passage?

A. Ancient Romans - the grain goddess Ceres. '

B. Native Americans - the Corn Grandmother.

C. Christians - the god Lugh and his foster-mother Taillte.

D. The Celts - Lugh, the Sun-King.

4. From the last sentence of the 4th paragraph "At this time oaths were taken and contracts were

   signed", we can infer that the Celts are ______.

A. happy at that time    

B. Serious about the day  

C. are full of hope        

D. thankful at that time

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