Wednesday, October 19, 2016

How Did Recent Ice Ages Impact Brazil?

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. 


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. 

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

Sunday, October 16, 2016

History of Brazil's Geography

Back in Time 

Brazil is entirely on the South American Platform- a portion of the South American plate that is continental. Evidence suggests the South American Plate broke from Pangea- the super-continent formed approximately 300 million years ago. The Nazca plate has been converging with the South American plate for the past 70 million years. This convergence partially led to the formation of the Andes- a massive mountain range in Brazil. Brazil became solid on the South American plate sometime in the Paleozoic period- the oldest era of the Proterozoic period.

The dark red section is Brazil which rests on the South American Plate 

Sources

http://www.brcactaceae.org/geology.html
https://www.britannica.com/science/Proterozoic-Eon
http://americastectonics.weebly.com/south-american-plate.html

Current Climate of Brazil

Perfect Vacation Spot

Because of Brazil's tropical location, the region is perfect for a warm vacation getaway. In the winter time, temperatures on average range from 55 to 64 degrees Fahrenheit, and the summer range is between 86 and 104 degrees Fahrenheit. Winter time is Brazil is three months long- June to August. Brazilian summer, on the other hand, is from December to February. Though the warm temperatures of the summer in Brazil are appealing, they come with frequent rainfall and a high humidity. 



The table above shows the average monthly temperatures in Brasilia, Brazil's capital, from 2010 to 2015.



Different Climate Conditions

Brazil is a massive country that houses various climate conditions. On the coast, it is hot and humid for most of the year, with a dryer season from March to November. Similarly, the Amazon jungle and surrounding areas are the hottest in the region, and have incredibly humid conditions. In the southern part of Brazil in the mountains, air temperatures can be a lot colder than the country's average, even dropping as low as 32 degrees Fahrenheit.


A rain forest in the Amazon Jungle where temperatures can reach up to 104 degrees Fahrenheit


Sources

http://www.worldtravelguide.net/brazil/weather-climate-geography
https://weather-and-climate.com/average-monthly-Rainfall-Temperature-Sunshine-in-Brazil
https://weather-and-climate.com/average-monthly-Rainfall-Temperature-Sunshine,Brasilia,Brazil
http://www.buzzle.com/articles/amazon-rainforest-facts.html