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Posts tagged Currents

Point Reyes, the Marin Hills and San Francisco, California

38.0N 122.8W

August 7th, 2009 Category: Snapshots

California, USA - July 3rd, 2009

California, USA - July 3rd, 2009

Water currents in the Pacific Ocean off the west coast of California make interesting patterns as they swirl around Point Reyes (top) and out of the San Francisco Bay (right).

Point Reyes is a prominent cape in Marin County approximately 30 mi (48 km) west-northwest of San Francisco. The term is often applied to the Point Reyes Peninsula, the region bounded by Tomales Bay on the northeast and Bolinas Lagoon on the southeast. The headland is protected as part of Point Reyes National Seashore. In this orthorectified image, Inverness Ridge can be seen running along the peninsula’s northwest-southeast spine.

To the southeast, the city of San Francisco glows at the northern end of the San Francisco Peninsula, with the Pacific Ocean to the west and San Francisco Bay to the east. The Golden Gate Bridge can be seen connecting the peninsula to the Marin Hills in southern Marin County.

Part of the San Francisco-Oakland Bay Bridge (to the right of the Golden Gate) and the Richmond-San Rafael Bridge (above the Bay Bridge) can also be seen.

Mount Etna, Sicily

37.7N 14.9E

July 26th, 2009 Category: Volcanoes

Italy - July 1st, 2009

Italy - July 1st, 2009

Wind and water currents, as well as passing ships, create different patterns in the Strait of Messina and the Mediterranean Sea, between Sicily and mainland Italy.

Onland, another interesting feature of this orthorectified image includes the  Mount Etna volcano (lower left), whose flanks are covered in fertile volcanic soil that supports extensive agriculture. The sides of the volcano appear smoother in contrast with the mountains and hills to the north.

Santo Antão and São Vicente, Cape Verde

17.0N 25.1W

July 26th, 2009 Category: Snapshots

Cape Verde - July 1st, 2009

Cape Verde - July 1st, 2009

Santo Antão (above) is the westernmost and largest of the Barlavento islands of Cape Verde. The nearest main island is São Vicente to the southeast, separated by a channel named Canal de São Vicente. The lines in the water in and near this channel indicate that the current is moving westward, around the islands.

The island is entirely made up of volcanic material. The island is divided into north and south by a mountain range, whose peaks can be seen clearly in this orthorectified image. The tallest mountain is Topo de Coroa, reaching a height of 1,979 m. The second tallest is Pico da Cruz at 1,585 m.

São Vicente (below), also belonging to the Barlavento islands group of Cape Verde, is roughly rectangular in shape with a surface area of about 227 km2 (88 sq mi). From east to west it measures 24 km (15 mi) and from north to south no more than 16 km (9.9 mi).

Although volcanic in origin, the island is quite flat. Its highest point is Monte Verde, located in the northeast-central part with an altitude of 725 metres (2,380 ft).  Other mountaintops include Monte Cara and Topona. Although a great amount of erosion has taken place, some craters still remain — in particular near the bay of Mindelo.

Ice off Greenland’s East Coast

79.4N 21W

June 17th, 2009 Category: Snapshots

Greenland - June 7th, 2009

Greenland - June 7th, 2009

Part of Greenland’s eastern coast is visible here, bordered by the Greenland Sea. All towns and settlements of Greenland are situated along the coast, although the population is concentrated along the west coast.

Here, changes in ice solidity create swirled patterns in the sea. This arm of the Arctic Ocean is the ocean’s main outlet to the Atlantic. The progressively colder waters of North Atlantic Current sink in the Arctic Ocean, returning south in the form of cold East Greenland Current, an important part of the Atlantic conveyor belt.

The Aeolian Islands, Italy

38.4N 14.9E

June 4th, 2009 Category: Volcanoes

Aeolian Islands and Sicily, Italy - May 11th, 2009

Aeolian Islands and Sicily, Italy - May 11th, 2009

The Aeolian Islands or Lipari Islands are a volcanic archipelago in the Tyrrhenian Sea north of Sicily.  Above, in the full image, the spiralling shape of currents in the sea is visible.

The largest island is Lipari (in the thumbnail image, the fourth from the left edge). The other islands include Vulcano, Salina, Stromboli, Filicudi, Alicudi, Panarea and Basiluzzo.

The present shape of the Aeolian Islands is the result of volcanic activity over a period of 260,000 years.

There are two active volcanoes – Stromboli (in the full image, the island farthest north) and Vulcano (to the right of Lipari). However, most of the islands experience volcanic activity from steaming fumaroles and thermal waters.

Below, on the island of Sicily, the famous Mount Etna volcano can also be observed. As this image has been orthorectified, the volcano and the mountains and hills in this area can be seen without geometric distortion.