冰期和间冰期在地球的历史时期里,曾经数度出现气候异常寒冷、冰川广布的时期,称为“冰期”。在冰期里,地球的年平均温度比现在大约要低10～15℃。当时,全球至少有三分之一以上的陆地被冰雪所覆盖,冰层的厚度平均为1000米左右。由于大量的水变成冰堆积在陆地上,竟使全球的海面比今天要低130～200米,露出了今天被我们称为大陆架的广阔浅海区域。 Ice Age and Interglacial Period In the historical period of the earth, there were several occasions when the climate was unusually cold and the glacier was widespread, which was called “Ice Age.” In the ice age, the Earth's annual average temperature is about 10 ~ 15 ℃ lower than now. At the time, at least one-third of the world's land was covered by ice and snow, with an average ice thickness of about 1,000 meters. As vast amounts of water have become ice-laden on land, the global sea surface has been 130 to 200 meters below today's sea level, revealing vast shallow-sea areas that we call today the continental shelf.