Density currents drive 3D movements within the world’s oceans that dwarf surface currents by volume. Density-driven movements due to temperature/salinity differences keep the world’s oceans well mixed & help to re-distribute heat from tropical areas towards polar areas. Resultant upwelling creates some of the world’s richest ocean ecosystems. Density movements known as turbidity currents are the world’s largest
The sediment in Lake El'gygytgyn, (pronounced EL-ge-GIT-gin) located in NE Siberia, holds one of the longest records of climate change anywhere in the continental Arctic. How does sediment (clay and mud) tell us something about past climate? Proxy data! By studying the microfossils of diatoms and pollen in the sediment, we can re-construct the lake environment millions of