Previous Glacial Period
From 110,000 to 12,000 years ago, the Earth experienced the most recent glacial period. This time period was during the pleistocene epoch when ice covered a vast amount of the world. Large sheets of ice covered most of North America, northern Europe, and Asia. Parts of South America were also covered in large ice caps. Since the sea level was around 120 meters lower during the last glacial period than it is today, Brazil was affected by this ice age. The weight of the ice pushes down on the Earth's crust, which displaces the fluid mantle under the crust and causes a bulge. When that ice melts, then, the crust slowly returns back to its normal state. Since the entire world was affected by this period, it can be assumed that Brazil experienced some of this bulging and re-stabilizing.
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| A map of the world during the last ice age. Notice the white ice caps extending up South America into Brazil. |
Ice Age Effects on South American Climate
Until recently, many researchers believed that South America, the continent in which Brazil lies, was dry and arid during the ice ages of the pleistocene epoch. Sediment core samples from Lake Titaca shows 25,000 years of precipitation records that may disprove the theory of dryness. Geologist Paul Baker and his colleagues took core samples, some up to 46 feet long, from the bottom of the lake. After analyzing the oxygen, magnetism, concentrations of calcium carbonate, and fossils of algae, the scientists concluded that the lake's surroundings were wet during the last Ice Age. Brazil, which neighbors both Peru and Bolivia where the lake lies, then, would have also had a wet climate during the last ice age.
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| Lake Titaca which lies between the border of Peru and Bolivia. The lake is close to Brazil. |
Sources
https://www.scientificamerican.com/article/ice-age-south-america-was/
http://bodaciousdreamexpeditions.com/fox-glacier-mega-magilla/
http://www.crystalinks.com/laketiticaca.html
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