February 4th, 2010 Category: Image of the day, Volcanoes

USA - December 20th, 2009

The full version of this orthorectified image stretches from the northernmost point of the island of Hawaii, across the volcano of Mauna Loa, to Ka Lae (or South Point), the southernmost point on the island.

As one may suppose from the area occupied by the volcano in the full image, it is the largest volcano on earth. This active shield volcano has a volume of about 18,000 cubic miles (75,000 km³), although it is not the highest peak on the island.

Ka Lae, also known as South Point, is the southernmost point on the Big Island of Hawaii as well as the southernmost point of the 50 United States. A confluence of ocean currents just offshore makes this spot one of Hawaii’s most popular fishing spots, although dangerous for swimming. The confluence of currents also means the area is prone to accumulation of marine debris.

Tags: ASAR Hawaii Ka Lae Mauna Loa Orthorectification South Point USA |  Print This Post |  Email This Post | | Leave a comment

February 3rd, 2010 Category: Snapshots

Italy - December 16th, 2009

The Venetian Lagoon, along the coast in the lower half of this  orthorectified image, is the enclosed bay of the Adriatic Sea in which the city of Venice is situated. The lagoon is the largest wetland in the Mediterranean Basin.

The Venetian Lagoon stretches from the River Sile in the north to the Brenta in the south, with a surface area of around 550 km². It is around 8% land, including Venice itself and many smaller islands. About 11% is permanently covered by open water, or canal, as the network of dredged channels are called, while around 80% consists of mud flats, tidal shallows and salt marshes.

It is connected to the Adriatic Sea by three inlets: the Lido, Malamocco and Chioggia inlets. Sited at the end of a largely enclosed sea, the lagoon is subject to high variations in water level, the most extreme being the spring tides known as the acqua alta (Italian for “high waters”), which regularly flood much of Venice.

Tags: Adriatic Sea ASAR Brenta River Chioggia Inlet Europe Italy Lido Inlet Malamocco Inlet Mediterranean Basin Orthorectification River Sile Venetian Lagoon Venice |  Print This Post |  Email This Post | | Leave a comment

January 31st, 2010 Category: Image of the day, Volcanoes

USA - December 14th, 2009

Valles Caldera (or Jemez Caldera), is a 12-mile-wide collapsed volcanic caldera in the Jemez Mountains of northern New Mexico, visible as a circular area towards the center of this orthorectified image. It is part of the Valles Caldera National Preserve, created on July 25th, 2000. The preserve has a land area of 89,716 acres (140.18 sq mi, or 363.07 km2), and is located in northeastern Sandoval County and southern Rio Arriba County, just west of Los Alamos.

Valles Caldera is one of the smaller volcanoes in the supervolcano class. The circular topographic rim of the caldera measures 19 kilometers (12 miles) in diameter. The caldera and surrounding volcanic structures are the most thoroughly studied caldera complex in the United States.

The Valles Caldera is the younger of two calderas known at this location, having collapsed over and buried the Toledo Caldera, which in turn may have collapsed over yet older calderas. The associated Cerros del Rio volcanic field, which forms the eastern Pajarito Plateau and the Caja del Rio, is older than the Toledo Caldera. These two large calderas formed during eruptions 1.47 million and 1.15 million years ago. The caldera and surrounding area continue to be shaped by ongoing volcanic activity.

Tags: ASAR Caja del Rio Cerros del Rio Volcanic Field Jemez Caldera Jemez Mountains Los Alamos New Mexico Orthorectification Pajarito Plateau Rio Arriba County Sandoval County Toledo Caldera USA Valles Caldera Valles Caldera National Preserve |  Print This Post |  Email This Post | | Leave a comment

January 30th, 2010 Category: Image of the day, Volcanoes

Equatorial Guinea - December 20th, 2009

Bioko, lower left quadrant, is an island off the west coast of Africa in the Gulf of Guinea. It is part of Equatorial Guinea despite its proximity to Cameroon (top). Bioko has a total area of 2,017 km2 (779 sq mi). It is 70 km long from north-northeast to south-southwest, and about 32 km across. It is volcanic and very mountainous with the highest peak Pico Basile (3,012 m (9,882 ft)). It lies on the Cameroon Volcanic Line.

In this orthorectified image, the city of Malabo can be seen on the northern coast of Bioko. The city, which is the capital of Equatorial Guinea, is located on the rim of a sunken volcano. Its population has grown rapidly over the past ten years to about 100,000.

Tags: Africa ASAR Bioko Island Cameroon Cameroon Volcanic Line Equatorial Guinea Gulf of Guinea Malabo Orthorectification |  Print This Post |  Email This Post | | Leave a comment

January 29th, 2010 Category: Rivers

USA - December 19th, 2009

The Brooks Range is a mountain range that stretches from west to east across northern Alaska, USA, and into Canada’s Yukon Territory. The total length of the range is about 1100 km (700 mi), although only a section in Alaska is visible in this orthorectified image.

The mountains top out at over 2,700 m (9,000 ft). Mount Chamberlin, 9020 ft (2,749 m), is the highest peak in the range. Other notable peaks include Mount Isto, 8,975 ft (2,736 m) and Mount Michelson, 8,855 ft (2,699 m). The range is believed to be approximately 126 million years old.

Upon opening the full image, several rivers can be seen flowing down from the mountains, including the Colville River. It rises in an isolated area of the DeLong Mountains, at the western end of the Brooks Range, north of the continental divide in the southwestern corner of the National Petroleum Reserve.

Tags: Alaska ASAR Brooks Range DeLong Mountains Orthorectification USA |  Print This Post |  Email This Post | | Leave a comment

January 28th, 2010 Category: Mountains, Snapshots

Spain - January 3rd, 2010

The peninsula reaching out from mainland Spain into the Mediterranean Sea in this orthorectified image is the Cap de Creus (meaning Cape of Crosses in Catalan). It is located at the far northeast of Catalonia, some 25 km south from the French border.

It is a peninsula of 190 square kilometres of an extraordinary landscape value; a very rocky dry region, with almost no trees, in contrast with a seaside rich in minuscule creeks of deep blue sea to anchor. Mountains are the last eminences of the Pyrenees which make the natural border between France and Spain.

Tags: ASAR Cap de Creus Catalonia France Mediterranean Sea Orthorectification Spain |  Print This Post |  Email This Post | | Leave a comment

January 27th, 2010 Category: Image of the day, Volcanoes

Galapagos Islands, Ecuador - January 5th, 2010

The ring-like structures on Isabela Island (right) and Fernandina Island (bottom), in this orthorectified image of the Galapagos Islands, are volcanic caldera. Isabela Island, the largest of the group, was formed by several volcanoes. Here, Volcán Wolf (above) and Volcán Darwin (below) can be observed.

Fernandina Island is an active shield volcano and youngest of the Galápagos Islands. The summit caldera is about 6.5 km (4 miles) wide. The caldera underwent a collapse in 1968, when parts of the caldera floor dropped 350 meters. A small lake has intermittently occupied the northern caldera floor, most recently in 1988.

Tags: ASAR Darwin Volcano Ecuador Fernandina Island Galapagos Islands Isabela Island Orthorectification South America Volcán Darwin Volcán Wolf Wolf Volcano |  Print This Post |  Email This Post | | Leave a comment

January 26th, 2010 Category: Mountains, Snapshots

Mexico - December 20th, 2009

This orthorectified image shows the Sierra de la Giganta, a mountain range of Baja California Sur state in northwestern Mexico. The range extends parallel to the coast of the Gulf of California, west of the town of Loreto. The Sierra de la Giganta is one of the landforms in the Peninsular Ranges, which extend 1500 km (900 miles) from Southern California to the southern tip of the Baja California Peninsula.

Also visible is the large Bahía Concepción,  upper left quadrant, a bay on the east coast of the state of Baja California Sud. It is one of the largest bays in the state, between the Baja California Sud peninsula’s mainland and the rocky, barren Concepción Peninsula.

Tags: ASAR Bahía Concepción Baja California Peninsula Baja California Sur Concepción Peninsula Gulf of California Loreto Mexico Orthorectification Peninsular Ranges Sierra de la Giganta |  Print This Post |  Email This Post | | Leave a comment

January 25th, 2010 Category: Image of the day, Rivers

USA - December 19th, 2009

The Kuskokwim River or Kusko River is an approximately 724 mile (1,165 km) long river in southwest Alaska. It is the ninth largest river in the United States of America, ranked by average discharge volume at its mouth; seventeenth largest by basin drainage area.

The river provides the principal drainage for an area of the remote Alaska Interior on the north and west side of the Alaska Range, flowing southwest into Kuskokwim Bay on the Bering Sea. Except for its headwaters in the mountains, the river is broad and flat for its entire course, making it a useful transportation route for many types of watercraft.

In this orthorectified image it can be seen in a more mountainous area, flowing past two buttes (center and left edge) that reach elevations of over 3000 feet.

Tags: Alaska Alaska Range ASAR Kusko River Kuskokwim River Orthorectification USA |  Print This Post |  Email This Post | | Leave a comment