#E1523D
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Pale Blue dot
Seen from about 6 billion kilometers (3.7 billion miles), Earth appears as a tiny dot (the blueish-white speck approximately halfway down the brown band to the right) within the darkness of deep space.
Sagan pointed out that “all of human history has happened on that tiny pixel (shown here inside a blue circle), which is our only home” (speech at Cornell University, October 13, 1994.)
via: wiki
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Real-time Earthquake Map -
Ianna Andréadis, Terres, 1985/1986
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On October 28, 2002, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this true-color image of the ongoing eruption of Europe’s largest and most active volcano, Mt. Etna, on the island of Sicily. The volcano’s thermal signature was detected by MODIS and is marked with a red overlay. On the northern slopes of the volcano, the thermal signature is possibly a second lava flow. A dense plume of what is likely ash and smoke is streaming southward from the volcano and out over the Mediterranean Sea.
via: Earth Observatory
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An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth’s surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of extra cold climate are termed “glacial periods” (or alternatively “glacials” or “glaciations” or colloquially as “Ice Age”), and intermittent warm periods are called “interglacials”.
Glaciologically, ice age implies the presence of extensive ice sheets in the northern and southern hemispheres; by this definition we are still in the ice age that began at the start of the Pleistocene (because the Greenland and Antarctic ice sheets still exist).
Glacials are characterized by cooler and drier climates over most of the Earth and large land and sea ice masses extending outward from the poles. Mountain glaciers in otherwise unglaciated areas extend to lower elevations due to a lower snow line. Sea levels drop due to the removal of large volumes of water above sea level in the icecaps. There is evidence that ocean circulation patterns are disrupted by glaciations. Since the Earth has significant continental glaciation in the Arctic and Antarctic, we are currently in a glacial minimum of a glaciation. Such a period between glacial maxima is known as an interglacial.
The Earth has been in an interglacial period known as the Holocene for more than 11,000 years. It was conventional wisdom that “the typical interglacial period lasts about 12,000 years,” but this has been called into question recently. For example, an article in Nature argues that the current interglacial might be most analogous to a previous interglacial that lasted 28,000 years. Predicted changes in orbital forcing suggest that the next glacial period would begin at least 50,000 years from now, even in absence of human-made global warming. Moreover, anthropogenic forcing from increased greenhouse gases might outweigh orbital forcing for as long as intensive use of fossil fuels continues. At a meeting of the American Geophysical Union (December 17, 2008), scientists detailed evidence in support of the controversial idea that the introduction of large-scale rice agriculture in Asia, coupled with extensive deforestation in Europe began to alter world climate by pumping significant amounts of greenhouse gases into the atmosphere over the last 1,000 years. In turn, a warmer atmosphere heated the oceans making them much less efficient storehouses of carbon dioxide and reinforcing global warming, possibly forestalling the onset of a new glacial age.
Left Picture: Minimum (interglacial, black) and maximum (glacial, grey) glaciation of the northern hemisphere.
Right Picture: Minimum (interglacial, black) and maximum (glacial, grey) glaciation of the southern hemisphere. -
World of Change: Urbanization of Dubai
To expand the possibilities for beachfront tourist development, Dubai, part of the United Arab Emirates, undertook a massive engineering project to create hundreds of artificial islands along its Persian Gulf coastline. Built from sand dredged from the sea floor and protected from erosion by rock breakwaters, the islands were shaped into recognizable forms, including two large palm trees. The first Palm Island constructed was Palm Jumeirah, and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite observed its progress from 2000 to 2011.
In these false-color images, bare ground appears brown, vegetation appears red, water appears dark blue, and buildings and paved surfaces appear light blue or gray. The first image, acquired in November of 2000, shows the area prior to the island’s construction. The image from February 2002, shows the barest beginnings of the artificial archipelago. By October 2002, substantial progress had been made on Palm Jumeirah, with many sandy “palm fronds” inside a circular breakwater.
By November 2003, the palm tree has been constructed, and buildings and vegetation populate Palm Jumeirah in the images from November 2004, October 2005, September 2006, March 2007, and November 2008. The final image, acquired in February 2011, shows vegetation on most of the palm fronds, and numerous buildings on the tree trunk.
Inland, changes are just as dramatic between November 2000 and February 2011. In the earliest image, empty desert fills the lower right quadrant of the image, as cityscape primarily hugs the coast. As the years pass, urbanization spreads, and the final image shows the area almost entirely filled by roads, buildings, and irrigated land.
Look at the animation and learn more: earthobservatory
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A satellite composite image of Antarctica (Blue Marble)
via: Wikinfo
