General Interest Publication on the structure of the planet Earth including the crust, the mantle, and the core with drawings to scale on the cover and a table listing the thickness of the parts.
Explains what we know about the early history of the earth and how we study the deposits formed during that time to understand the formation of the earth and life.
Information on the Earth's crust with a contour map of the thickness plus links to a global crustal database, a global crustal model - CRUST 5.1, and regional crustal models.
Discussion and diagrams on plate tectonics and the structure of the Earth for beginners with link to a detailed version: This Dynamic Earth for more information.
We estimate mean volumes of 896 million barrels of oil and about 53 trillion cubic feet of nonassociated natural gas in conventional, undiscovered accumulations within this area, a reduction of our 2002 estimate due to new geologic information.
Long-term reduction in rainfall and increasing temperature threaten Chad's future food production prospects; combined with rapid population growth and zones of substantial conflict, increasing numbers of people will be at risk.
Recent trends in March-June, June-September, and March-September rainfall and temperature, identifying significant reductions in rainfall and increases in temperature over time in this area.
Summer rains have remained steady for the past 20 years, but are below the long-term average. Current population and agricultural trends indicate increasing yields have offset population expansion, keeping per capita cereal production steady.