Using measurements of the elevation of the Antarctic ice sheet made by a suite of satellites, the researchers found that the Southern Antarctic Peninsula showed no signs of change up to 2009. Around 2009, multiple glaciers along a vast coastal expanse, measuring some 750km in length,
Sunday, May 24, 2015
Savannahs slow climate change, experts say
Tropical rainforests have long been considered Earth's lungs, sequestering large amounts of carbon dioxide from the atmosphere and thereby slowing down the increasing greenhouse effect and associated human made climate change. Scientists in a global research project now show that the vast extensions of semi-arid landscapes occupying the transition zone between rainforest and desert dominate the ongoing increase in carbon sequestration by ecosystems globally, as well as large fluctuations between wet and dry years.
Tuesday, May 13, 2014
Sunday, May 11, 2014
Types of Mountains
Mountains make up a large proportion of the earth's surface. Based on their mode of formation, four main types of mountains can be distinguished.
1. Fold mountains. These mountains are by far the most widespread and also the most important. They are caused by large-scale earth's movements, when stresses may be due to the increased load of the underlying rocks, flow movements in the mantle, magnetic intrusions into the crust, or the expansion or contraction of some part of the earth. When such stresses are initiated, the rocks are subjected to compressive forces that produce wrinkling or folding along the lines of weakness. Folding effectively shortens the earth's crust, creating from the original level surface a series of waves. The upfolded waves are called anticlines and the troughs or downfolds are synclines.
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