While travelling through Namibia’s hot and sandy Namib Desert or barren Skeleton Coast, it is hard to imagine that this area was once covered by ice and snow. However, geological formations in the Namib Desert, in a remote region between the Huab and Ugab rivers suggest that this may have been the case.
During 1990, geologists led by Paul Hoffman first noted similarities between rocks found in these mountainous deserts of Namibia, and the kind of rocks that are forming beneath the Arctic today due to glacial activity. This indicates that the Namib rocks also came into existence while submerged beneath icy tundra, and even the ocean, at some point in the earth’s history all those millennia ago.
This discovery adds credibility to Brian Harland’s ‘Snowball Theory’ of 1964, which suggests that during the Pre-Cambrian era (700 million years ago), the continents were all bunched together in the Southern Hemisphere and that the planet was covered almost totally by glacial ice sheets.
According to this theory, for tens of millions of years, Earth was quite literally a giant sphere of ice and snow revolving lifeless through space.
Although ‘Snowball Theory’ can still not be proved beyond a shadow of doubt, these Namibian discoveries have increased the probability of this early ice age.
In theory, it is possible that reduced solar radiation and a decrease in greenhouse gases would cause the polar ice sheets to grow. If ice continued to form below about 30 degrees latitude this would cause ‘ice-albedo’ feedback, which in turns leads to surface temperatures falling. This ice albedo feedback refers to the reflection of the sun off the white surface of the ice, i.e. more ice leads to more reflection which leads to a decrease in temperature, which in turn leads to more ice forming and so on.
Although many scientists have their doubts as to how life on earth survived this, there are organisms in the Arctic that thrive in these extreme temperatures. It’s believed that volcanic activity after the ‘big freeze’ served to melt the ice bit by bit and add warming CO2 to the atmosphere, gradually reclaiming land from the sea.
It is fascinating to imagine the underwater world that once existed here and the timelessness of the rocks and stones upon which we tread, and it’s a past that deserves to be visited. Why not take a trip to the fascinating world of the Namib Desert and see these remarkable discoveries yourself?