sway n.v.摇摆;摆动;影响;控制;
wax and wan 兴衰
关于冰川纪出现的周期和长度有不同学说。1说是轮回出现,因为绕日公转,阳光照射程度不同。2说地球变冷和变热是相互独立的,研究了沙漠里面一个洞里的水,跟海洋沉积物里面的数据不一样。还有些人支持1,说2的数据是错的
P1 theory 1: occurred in cycles
- Earth sways while orbiting >> fluctuations in the density of sunlight
- MM's evidence: oxygen isotopes>>ocean sediments
P2 new study: warmed and cooled independently
- Study DH
○ IW
○ Rate of decay of u to r
○ Data differ significantly
○ Suggesting: warm periods twice longer
- Conclusion: ice ages >complex interactions
P3 some scientist: critic new study
- Due to geo variation in climate/marine or freshwater
1. Theory to explain ice age: depends on earch's orbit cycle around the sun
2. Opposing theory: by checking mineral data, M says the warm age and ice age are depend on more complex interaction btw thing on earth
Other opinion: science support throey1 and reject 2 for the data is incorrect
主题:有关冰川周期形成原因的几种观点讨论
MM:earth sway → ice cycle
--JI supportxygen isotopes in shells
W:interaction →cycle
--uranium data ≠ sediments data
I:+MM; explain the difference in studies