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Photosynthetic Activity of Italy and Coastal Tunisia and Algeria

40.2N 13.3E

November 29th, 2009 Category: Snapshots

Italy - November 17th, 2009

Italy - November 17th, 2009

This FAPAR image shows the vegetation index of Italy, including the islands of Sardinia and Sicily, as well as Corsica and parts of coastal Tunisia and Algeria. The vegetation index corresponds to the Fraction of Absorbed Photosynthetically Active Radiation, which provides data on the planet’s climate system.

In FAPAR images, the color spectrum over land runs from red (1.0), to green, to yellow and white (0.0), while bodies of water appear blue. Dark red regions correspond to agricultural zones for which there is high photosynthetic activity and therefore vegetation productivity, while yellow to white areas, with the exception of white patches of clouds,  indicate a low degree of photosynthetic activity.

Here, some red areas can be seen on the islands of Sardinia and Sicily, while most of Italy and Corsica appears green with some yellow zones. Algeria and Tunisia show photosynthetic activity near the coast, while the area further south is yellow and white, reflecting the low photosynthetic activity of more arid regions.

Santander and Mountains of the Cantabria Region, Spain

43.4N 3.8W

November 28th, 2009 Category: Snapshots

Spain - November 12th, 2009

Spain - November 12th, 2009

Cantabria is a Spanish historical region and autonomous community, bordered on the north by the Cantabrian Sea. Its capital city is Santander, visible at the top center of this orthorectified image along the shores of Santander Bay, the most prominent indentation in the coastline.

Cantabria is a mountainous and coastal region, with important natural resources. The coastal area is a strip of low, wide and gently rolling valleys some 10 kilometers in width, whose altitude does not rise above 500 meters, and which meets the ocean in a line of abrupt cliffs broken by river estuaries, creating rias and beaches.

To the south, the coastal strip rises to meet the Cantabrian mountains. This is a long barrier made up of abruptly rising mountains parallel to the sea. The ranges are mostly made of limestone with karst topography, and occupy most of Cantabria’s area. They form deep valleys oriented north-south. The torrential rivers are short, fast flowing and of great eroding power, so the slopes are steep.

The valleys define different natural regions, delimited physically by the intervening mountain ranges: Liébana, Saja-Nansa, Besaya, Pas-Pisueña, Miera, Asón-Gándara and Campoo. The Escudo Range, a mountain range of 600 to 1,000 metres high that covers 15 or 20 km in a parallel line to the coast in the west part of Cantabria.

Towards the south are higher mountains, whose crests mark the watershed between the drainage basins of the Rivers Ebro, Duero and those that flow into the Bay of Biscay. These peaks generally exceed 1,500 m from the Pass of San Glorio in the west to the Pass of Los Tornos in the eastern part: Peña Labra, Castro Valnera and the mountain passes of Sejos, El Escudo and La Sía. The great limestone masses of Picos de Europa also stand out in the southwest of the region: most of their summits exceed 2,500 m, and their topography is shaped by the former presence of glaciers.

Sandstone Buttes in Northern Arizona, USA

35.3N 110.3W

November 27th, 2009 Category: Snapshots

USA - November 15th, 2009

USA - November 15th, 2009

Clusters of high sandstone buttes characterize this part of the Colorado Plateau in Navajo County, in the state of Arizona, USA. The largest buttes in this orthorectified image reach 6400 feet above the valley floor.

A butte is a conspicuous isolated hill with steep, often vertical sides and a small, relatively flat top; it is smaller than mesas, plateaus, and tables. In some regions the word is used for any hill; however, in differentiating mesas and buttes, geographers use the rule that a mesa has a top wider than its height, while a butte’s top is narrower.

The buttes here are located in Navajo County, in the northern part of Arizona. The county contains parts of the Hopi Indian reservation, the Navajo Indian Reservation and Fort Apache Indian Reservation.

According to the U.S. Census Bureau, the county has a total area of 9,959 square miles (25,795 km²), of which, 9,953 square miles (25,779 km²) of it is land and 6 square miles (16 km²) of it (0.06%) is water.

Desert of Rub’ al Khali on the Arabian Peninsula

19.7N 49.9E

November 26th, 2009 Category: Snapshots

Saudi Arabia - November 16th, 2009

Saudi Arabia - November 16th, 2009

The southern half of the Arabian Peninsula, including Yemen, southern Saudi Arabia and Qatar, as well as parts of the United Arab Emirates and Oman, are visible here. Much of the area is occupied by the sand desert known as the Rub’ al Khali, or “Empty Quarter” in English.

It is one of the largest sand deserts in the world, encompassing most of the southern third of the Arabian Peninsula, including areas of all the countries mentioned above, with the exception of Qatar. In total, the desert covers some 650,000 square kilometres (250,000 sq mi). It is 1,000 kilometres (620 mi) long, and 500 kilometres (310 mi) wide.

Summer temperatures of nearly 55 °C (131 °F) and dunes over 330 metres (1,100 ft) make Rub’ al Kali one of the most forbidding environments on Earth. Geologically, the Empty Quarter is the second most oil-rich place in the world. Vast oil reserves have been discovered underneath the sand dunes.

Mountains of the Cabo de Gata-Níjar Natural Park, Spain

36.9N 1.8W

November 23rd, 2009 Category: Snapshots

Spain - November 12th, 2009

Spain - November 12th, 2009

Cabo de Gata-Níjar Natural Park is a nature reserve in southeastern Spain, near the city of Almería. The city is visible on the coast on the left side of this orthorectified image, while the park runs northeastward along part of the coastline starting at the bottom of the image.

It is the largest terrestrial-maritime reserve in the European Western Mediterranean Sea, covering 460 km² including the town of Carboneras, the mountain range of Sierra de Cabo de Gata, and 120 km² of the sea as a part of a marine reserve.

It is of volcanic origin and is centred around the Cabo de Gata headland. Cabo de Gata-Níjar Natural Park is characterised by volcanic rock formations – lava flows, volcanic domes, volcanic calderas.

Between the village of San Miguel and the Cabo de Gata Point are salt flats (Las Salinas de Cabo de Gata) separated from the sea by a 400 m (0.24 mi) sand bar. The salt flats are a Ramsar site.

The area is semi-arid to the extent of being the driest location in Europe. The average temperature is 18 °C and it has the lowest rainfall in the Iberian peninsula and all of Europe, its average precipitation being a mere 120 to 180 mm (4.72 to 7.09 in) annually.