Rocky Mountain National Park in Colorado contains many U-shaped glacial valleys, each of which ends at bowl-shaped region called a cirque. Cirques are the locations where glaciers accumulate most of their snow and ice, and so are the starting points for most glacial ice. Glacial erosion tends to create steep headwalls that frame in the cirque. The photo above shows the upper reaches of Glacier Gorge, which contains two cirques that merge downwards into one. The small peak (Spearhead) near the center of the photo forms a feature called an arete, as it separates the smaller cirques. (…) In the lower left corner, a hiker is perched on an outcrop of Proterozoic granite, directly in front of Longs Peak. Photo taken July 16, 2011. Credit: Marli Bryant Miller. (via EPOD)
Omulyakhskaya and Khromskaya Bays lie along the northern Siberian coast, southeast of the Lyakhov Islands. The northerly location almost guarantees ice in the adjacent East Siberian Sea, and permafrost blankets the land around the bays. The Thematic Mapper on the Landsat 5 satellite captured this natural-color image on June 15, 2009, when ice lingered on the sea surface and on some inland water bodies. The land around the bays is dotted with thermokarst lakes, which result from water released by thawing permafrost. (…) Because thawing permafrost and thermokarst lakes release carbon and methane—both greenhouse gases—scientists monitor these landscapes closely because of their implications for future climate. (via NASA Earth Observatory)
Puyehue Cordón Caulle Volcanic Complex emitted a pale plume of gas and ash on August 18, 2011. Activity started on June 4, 2011. The ongoing eruption has been characterized by explosive emissions of ash and larger tephra, as well as the outpouring of lava typical of an effusive eruption. Evidence of both styles of eruption are visible in this natural-color satellite image, acquired by the Advanced Land Imager (ALI) aboard Earth Observing-1. A billowing ash plume indicates the explosive nature of the eruption. A fresh lava flow, darker than most of the surrounding, snow-covered landscape, illustrates the effusive aspect of the eruption. Signs of an older eruption are visible to the southwest (lower left) of the fresh lava. A diagonal line of vents and craters marks the location of an eruption that started on May 24, 1960—only 38 hours after a magnitude 9.5 earthquake occured under the Pacific Ocean, about 200 kilometers (120 miles) away from Puyehue Cordón Caulle. This is one of the few eruptions conclusively linked to earthquake activity. Downslope from the vents are thick, snow-covered lava flows, similar in appearance to the lava emitted by the current eruption. (via NASA Earth Observatory)
Macizo del Mercedario (by Mono Andes)
Es la cuarta cumbre de América, de 6770 metros de altura y varios seis miles en el macizo: Cerro Mesa (6120), Polaco (6000), Mesa (6080), Ramada Norte (6410), Ramada Sur (6250), Alma Negra (6120). Como para quedarse. Provincia de San Juan, Argentina.
Fuente: Flickr / monolive
Earth from Space: Summer ice retreat (by europeanspaceagency)
In this image, acquired on 23 June 2011, Envisat captures part of Greenland’s ice sheet and east coast as the winter sea ice recedes. Covering roughly 80% of the surface of Greenland, this ice sheet is the second largest body of ice in the world, after that of Antarctica. Credits: ESA.
Fuente: Flickr / europeanspaceagency
These bizarre snow and ice formations, called “penitentes”, form in high-altitude regions such as the Chajnantor plain [Chile], close to where the ALMA array will be located. These are ice blades produced by the competition between sublimation and melting of the snow. At Chajnantor at the summer solstice, the Sun is close to the zenith at noon, and penitents are vertical. This image was taken in December 2005. Credit: ESO. (via ESO)
I snapped this photo of Mount St. Helens out of the window seat of flight from Vancouver to San Francisco last summer. The explosive eruption of Mount St. Helens on this day in 1980 caused extensive damage in the surrounding area and, unfortunately, 57 people lost their lives. A massive landslide on the flank of the volcano resulted in material erupting from the side as well as up into the atmosphere. You can see the evidence of that in the photo above (the big gap in the rim). (via Clastic Detritus)