August 20th, 2010 Category: Volcanoes

USA- August 14th, 2010

This orthorectified image shows Mount Veniaminof, an active stratovolcano located on the Alaska Peninsula. Veniaminof has one of the highest elevations of Alaskan volcanoes. Partly for this reason, it is covered by a glacier that fills most of the caldera.

The volcano’s caldera was created by a colossal eruption around 1750 BC. In modern times the volcano has had numerous small eruptions (over ten of them since 1930); these are located at a cinder cone in the middle of the caldera. The Alaska Volcano Observatory, however, currently rates Veniaminof at Volcano Alert Level normal.

Tags: Alaska Mount Veniamof Orthorectification USA |  Print This Post |  Email This Post | | Leave a comment

August 17th, 2010 Category: Image of the day, Lakes, Mountains, Sediments, Volcanoes

New Zealand - July 30th, 2010

The two main landmasses visible here are New Zealand’s North Island (above) and South Island (below). The two are separated by the Cook Strait.

Of note on the North Island are Lake Taupo, the dark blue lake in the center of the island, and several volcanoes: Mount Taranaki/Egmont (on a peninsula on the western side), Mount Ngauruhoe (south of Lake Taupo), and Mount Ruapehu (south of the former).

Of note on the South Island are the Southern Alps, the snow-capped mountain chain running down the backbone of the island, the sediments near the Banks Peninsula (central east coast), and the bright blue glacial lakes of the Mackenzie Basin (between the mountains and the southeastern shoreline).

Tags: Lake Taupo Mount Ngauruhoe Mount Ruapehu Mount Taranaki New Zealand |  Print This Post |  Email This Post | | Leave a comment

August 14th, 2010 Category: Volcanoes

Mexico - July 22nd, 2010

This APM image shows the Nevado de Toluca (center left), a large stratovolcano in central Mexico, located about 80 km west of Mexico City near the city of Toluca. The volcano has a 1.5 km wide summit caldera which is open to the west.

It is generally cited as the fourth highest of Mexico’s peaks, although by some measurements, Sierra Negra is slightly higher. The highest summit, 4680 m Pico del Fraile (Friar’s Peak), is on the south side of the crater and the second highest, 4640 m Pico del Aguila (Eagle’s Peak), is on the north.

There are two crater lakes on the floor of the basin at about 4200 m, the larger Lago del Sol (Sun Lake) and the smaller, but deeper, Lago de la Luna (Moon Lake).

Tags: APM Mexico Nevado de Toluca Volcanoes |  Print This Post |  Email This Post | | Leave a comment

August 12th, 2010 Category: Volcanoes

Libya - July 30th, 2010

The tan and golden sands of the Libyan Desert dominate this image of Libya in North Africa. One large, circular area towards the image center differs from its surroundings, as it is brown in color.

This area is the Haruj, a large volcanic field that covers approximately 45000 km2 in the center of the country. Around 150 volcanoes can be found in the field. Other volcanic formations include large craters, cones and lava flows.

Tags: Haruj volcanic field Libya Libyan Desert |  Print This Post |  Email This Post | | Leave a comment

August 10th, 2010 Category: Volcanoes

New Zealand - August 2nd, 2010

Mount Taranaki, or Mount Egmont, is an active but quiescent stratovolcano in the Taranaki region on the west coast of New Zealand’s North Island. The 2518-metre-high mountain is one of the most symmetrical volcanic cones in the world, similar in shape to Mount Fuji in Japan.

Taranaki is considered unusual in that it has experienced at least five of its major eruptions by the method of cone collapse. Few volcanoes have undergone more than one cone collapse. The vast volume of material involved in these collapses is reflected in the extensive ringplain surrounding the volcano. Here, that ringplain appears dark greyish green in color, in contrast to the bright green plains surrounding it.

Tags: Mount Egmont Mount Taranaki New Zealand Volcanoes |  Print This Post |  Email This Post | | Leave a comment

August 10th, 2010 Category: Image of the day, Mountains, Volcanoes

DRC and Rwanda - July 27th, 2010

This orthorectified image shows several volcanoes near the border of the Democratic Republic of the Congo and Rwanda. All of the volcanoes are located in the Virunga Mountains.

Near the center left is Mount Nyamuragira, an active volcano that is only 13 km north-north-west of Nyiragongo, the volcano which caused extensive damage to the city of Goma in its 2002 eruption.

Mount Nyiragongo, whose main crater is flanked by two other indentations, is a stratovolcano just west of the border with Rwanda. The main crater is about two km wide and usually contains a lava lake.

Moving eastward, one comes to the Mikeno Volcano. Southeast of that peak is Mount Karisimbi, an inactive volcano on the border between Rwanda and the DRC. At 4507 m, Karisimbi is the highest of the eight major mountains of the mountain range.

Karisimbi is flanked to the east by Mount Bisoke, an extinct volcano that straddles the border of Rwanda and the Democratic Republic of the Congo, although the summit is located in Rwanda.

The peak furthest east, near the right edge of the image, is Mount Sabyinyo, an extinct volcano. The summit of the mountain, at 3645 m, marks the intersection of the borders of the DRC, Rwanda, and Uganda.

Tags: Karisimbi Nyamuragira Nyiragongo Sabyinyo Virunga Mountains |  Print This Post |  Email This Post | | Leave a comment

August 6th, 2010 Category: Fires, Image of the day, Mountains, Volcanoes

Russia - July 30th, 2010

A wildfire in the upper part of Russia’s Kamchatka Peninsula blows a thick plume of smoke to the east-northeast. West of the blaze, a river spills brown sediments into Penzhina Bay.

Visible southwest of the fire are the snow-capped peaks of the Kamchatka Range, also known as the Central Range, which runs down towards the tip of the peninsula. Several nearby volcanoes appear capped with snow or ringed by clouds.

Tags: Fires Kamchatka Peninsula Penzhina Bay Russia |  Print This Post |  Email This Post | | Leave a comment

July 28th, 2010 Category: Image of the day, Lakes, Volcanoes

Iceland - July 21st, 2010

Several lakes and volcanic features can be observed in this orthorectified image of eastern iceland. The full image stretches from the Öxarfjörður fjord on the northern coast to the Vatnajökull glacier to the south.

Visible as a black patch near the upper edge of the image thumbnail is Mývatn, a shallow eutrophic lake situated in an area of active volcanism. The lake was created by a large basaltic lava eruption 2300 years ago, and the surrounding landscape is dominated by volcanic landforms, including lava pillars and rootless vents (pseudocraters).

Almost directly south of Mývatn is Öskjuvatn, a lake in the Highlands of Iceland. It is identifiable here by its ringed form due to its location in the crater of the volcano Askya, in the north-east of the glacier Vatnajökull. The lake’s surface area is about 11 km², and with a depth of 217 m it is the deepest lake in Iceland.

Northeast of Öskjuvatn is Kollóttadyngja, a volcano situated in the Ódáðahraun lava-field. Its height reaches 1,177 metres, with a diameter of 6–7 kilometers. The summit crater is 800 meters in diameter, but only about 20–30 meters deep, and in its center, there is a bowl of about 150 meters in diameter, with a depth of about 60–70 meters. This rounded shape is visible here.

Tags: Iceland Kollóttadyngja Mývatn Öskjuvatn Volcanoes |  Print This Post |  Email This Post | | Leave a comment

July 27th, 2010 Category: Image of the day, Lakes, Rivers, Volcanoes

Mexico - June 23rd, 2010

Greenish sediments flow forth from the Colorado River, around Montague Island, and into the Sea of Cortes, left of the image center. Upon opening the full image, more of the sea and the Baja California peninsula in Mexico can be observed.

Near the north shores of the sea is the Gran Desierto de Altar, part of the Sonoran Desert. The dark brown circular area amidst the tan dunes is the Pinacate Peaks (Sierra Pinacate), a volcanic group of volcanic peaks and cinder cones.

Following the river northwards, one comes to an irrigated area in this arid region – the Imperial Valley in southern California. Continuing northwards through the agricultural zone, one finds the Salton Sea, a saline lake. The largest such lake in California, it covers a surface area of approximately 376 sq mi (970 km2).

Tags: Colorado River Gran Desierto de Altar Pinacate Peaks Salton Sea |  Print This Post |  Email This Post | | Leave a comment