Advanced Placement Physics BC: Period 7
6 June 2011
Climate History from Deep Sea Sediments
In this lab, we were studying the effects of global warming by analyzing plankton life in oceanic sediment cores. Using the CHRONOS database, we found data for zones with two different species of plankton. First, we browsed between areas with bedrock between 50 million to 100 million years old, usually along but distanced from plate boundaries. These were easiest to find around Antarctica and the southern Atlantic Ocean. Using datasets provided within the Virtual Ocean program, we were able to locate appropriate drilling locations (specifically site 113-690B) and analyse the age-depth and vane shear models in graphs as shown below:
There is a notable change in shear strength circa 170m deep with an indicated change at 57.054 million years ago, indicating plankton death. We followed this result up with an analysis of two species, Acarinina praepentacamerata (red) and Morozovella velascoensis (blue), which was then highlighted in the following image:
These two species were found beyond their usual tropical regions and far closer to the South Pole, indicating that there was a change in water temperature due to their presence in typically cold environments despite their habituation for tropical climates. This appearance of plankton in new areas indicates that the PETM was a global event that affected climates around the world. The samples containing plankton near the South Pole shows that the water near Antarctica was warmed to near tropical temperatures. This warming shows a drastic change in climates around the world.
This data relates to thermodynamics and fluid dynamics. The spread of warm water throughout the world demonstrates the fluid dynamics of the ocean currents, while the increase in overall temperature of the earth shows the effects of thermodynamics. With only a slight increase in the energy being transferred to the earth, the temperature and climates can change dramatically.