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Traces of Humankind – South Africa

30.2S 24.6E

July 3rd, 2013 Category: Earth Observation, Snapshots VIIRS/MODISSuomi-NPP/Aqua

South Africa – July 1st, 2013

VIIRS – Night Visible Image

MODIS – True-Color Image

Satellite images are an incredible tool to assess the health status of the Earth.

However, while macro-effects of human activities are clearly evident (i.e. deforestation, oil spill, etc.), the real impact of mankind on our Planet was not always easy to identify from Space.

Sometimes it is possible to understand how a region is changing just by combining data from different satellite instruments. Paradoxically, sometimes you just simply turn off the light to notice details not otherwise visible.

The main image represents the combination of the Night band of the VIIRS instrument (on-board the NASA’s Suomi-NPP satellite) with the True-Color band combination of the MODIS instrument (on-board the NASA’s Aqua satellite).

The extent of urban areas captured by the Night Image is clearly visible using the True-Color Image as a background. Small agricultural fires are visible as small groups of white dots close to the major villages (in the middle right part of the image).

The city of Cape Town is visible in the lower left part of the image, while the municipalities of Johannesburg, Pretoria, Vereeniging, Brits and Rustenburg (in the upper right part of the image) show that the extent of the towns has become a single (giant) urban area.

In the small boxes at the beginning, the two images used for the combination.

Cities Along East Coast of China

23.6N 120.9E

June 30th, 2013 Category: Snapshots VIIRSSuomi-NPP

China – June 29th, 2013

The cities of Shanghai and Hangzhou (above) and Hong Kong (lower left) stand out along the shoreline of China, as do populated areas along the west coast of the island of Taiwan. Shanghai is China’s most populous city, situated on the eastern coast of the country, a port on the estuary of the Yangtze River.

Hong Kong is a former British dependency on the southeastern coast of China. The area comprises Hong Kong Island, the Kowloon peninsula, and the New Territories, additional areas of the mainland. Hong Kong has become one of the world’s major financial and manufacturing centers.

Cities of Southern USA

25.7N 80.2W

May 5th, 2013 Category: Snapshots

USA – May 5th, 2013

Cities, towns, and other reflective surfaces appear as a bright white web of circles and lines in this image of southern USA. With regards to population, more than half of the population growth in the USA in 2006 occurred in southern states. As of 2010, an estimated 114,555,744 people were living in the South, or thirty-seven percent of all of the U.S.

Cities and Towns Across Landscape of India

15.2N 75.2E

May 3rd, 2013 Category: Snapshots

India – May 2nd, 2013

Many cities and towns appear like starry constellations across the landscape of India. India is often cited as a country having an overpopulation problem. In nature, the evaluation of overpopulation is conceptually straightforward. If a group relies on a local area for its sustenance, then its population will be limited by the productivity of that area.

As of July 2003, India had a population of just over one billion. With around 170 million hectares of arable land, it has the potential to produce among the world’s highest crop yields. Whether or not this amount of food could sufficiently cover the needs of the population, two things are clear without dispute: millions of Indians’ fundamental biological needs are not met, and should the population continue to rise, it will not be possible to produce enough food to cover those needs (click here for more information).

Isthmus of Tehuantepec Between Gulf of Mexico and Pacific Ocean, Mexico

17.5N 94.5W

March 26th, 2013 Category: Snapshots

Mexico – March 23rd, 2013

The Isthmus of Tehuantepec is an isthmus in Mexico. It represents the shortest distance between the Gulf of Mexico and the Pacific Ocean. At its narrowest point, the isthmus is 200 km (120 mi) across from gulf to gulf, or 192 km (119 mi) to the head of Laguna Superior on the Pacific coast. The northern side of the isthmus is swampy and densely covered with jungle.

The Sierra Madre breaks down at this point into a broad, plateau-like ridge. Since Sierra Madre de Oaxaca mountains flatten out to form Chivela Pass before the Sierra Madre de Chiapas mountains resume to the south, geographically the isthmus divides North America from Central America.