ISS019 Earth Sciences and Image Analysis Photographic Highlights

TOP PICKS
Click here to view the complete online collection of astronaut photography of Earth >>

View larger image for ISS019-E-5989
ISS019-E-5989
Red River Floods, North Dakota and Minnesota: When this astronaut photo was captured on April 9, 2009, the Red River was experiencing its second round of spring flooding. (Two weeks earlier, the river had crested at very high levels.) The Red River flows north between North Dakota and Minnesota from the confluence of the Bois de Sioux River (south, image lower right) and the less well drained, meandering Otter Tail River (east, image right). Floodwaters in these two tributaries appear as black shapes against a snowy agricultural landscape that is defined by rectangular fields. The largest flooded areas are low parts of fields (image bottom) along a canalized western tributary of the Wild Rice River, which itself becomes a tributary of the Red River just south of Fargo, North Dakota.

Wahpeton, North Dakota, and Breckenridge, Minnesota, sit opposite each another on the banks of the Red River, and their city-block patterns stand out as dark gray patches against the snow at image top right. The main runway of the Henry Stern Airport lies angled northwest directly south of Wahpeton, and its 1.3-kilometers (0.8-mile) runway gives a sense of scale to the photo. Access roads to the agricultural fields tend to follow an orthogonal pattern, while larger roads leading to the cities cut across this pattern (image upper left, near Wahpeton). A subtle pattern of drainage ditches and plow lines appears as thin, parallel lines throughout fields in the scene.

View larger image for ISS019-E-5501
ISS019-E-5501
Dalmatian Coastline near Split, Croatia: One the world’s most rugged coastlines is located in Croatia along the Adriatic Sea. This astronaut photograph features the Dalmatian coastline of Croatia around the city of Split. Much of the region’s topography is characterized by northwest-southeast-oriented islands and embayments of the Adriatic Sea. These distinctive coastal land forms result from faulting (caused by tectonic activity in the region) and sea level rise since the end of the last ice age.

Split has a long history of human settlement. The Roman Emperor Diocletian retired to Spalatum (present-day Split) in 305, and his palace constitutes the core of the city today. The city is a popular resort destination for its historic sites, Mediterranean climate, and ready access to Adriatic Sea islands (such as Brac(, to the south). Other large cities in the region include Kaštela and Trogir; together with Split, these form an almost continuous urban corridor along the coast (visible as pink regions in the image).

A thin zone of disturbed water (tan patches) marking a water boundary appears in the Adriatic Sea between Split and the island of Brac(. It may be a plankton bloom or a line of convergence between water masses, which creates rougher water. A unique combination of features—including dramatic topography that channels local winds, the complicated coastline, input of fresh water from rivers, and ample nutrients and natural surface oils—produce interesting mesoscale surface dynamics throughout the Adriatic Sea. Over the years, astronauts have taken images of the Split region using sunglint (the mirror-like reflection of the Sun off water) and changes in water color to highlight features like eddies, water boundaries and mixing zones between fresh waters flowing into the saltier (denser) waters of the Adriatic, and wind-driven surface currents.

Split is an important transit center connecting islands in the Adriatic Sea to the Italian peninsula, and it is an important regional manufacturing center of goods such as solar cells, plastics, and paper products. The city was heavily industrialized during the post-World War II period as a member state of Yugoslavia. By the 1980s, the marine environment bordered by Split, Kaštela, and Trogir (known as Kaštela Bay) had become one of the most polluted areas of the Adriatic, both from sewage and industrial pollution. Concerted efforts by the Croatian government and international partners to improve waste handling and treatment infrastructure over the past 10 years seem to have been successful in improving water quality.

View larger image for ISS019-E-6499
ISS019-E-6499
Ankara, Turkey: The central portion of the capital city of Turkey, Ankara, is featured in this astronaut photograph. Ankara is located in central Turkey. The climate there is continental and relatively dry, leading to cold winters and hot summers. The region is prone to major earthquakes, as Turkey experiences tectonic forces from both the African plate to the west and the Arabian plate to the east. Despite the earthquake hazard, the city traces its roots back into antiquity, with a Hittite settlement here prior to 1200 BC. A citadel built and occupied in turn by the Galatians, Romans, Byzantines, and Seljuks overlooks the central portion of the city, and today serves as both a historical and recreational site. Perhaps an even more imposing structure—the mausoleum of the founder of the modern-day Republic of Turkey, Mustafa Kemal Atatürk—is visible on an adjacent hill to the southwest.

Hill slopes around the city (image left and right) are fairly green due to spring rainfall. One of the most striking aspects of the urban area is the almost uniform use of red brick roofing tiles, which contrast with lighter-colored roads; the contrast is particularly evident in the northern (image lower left) and southern (image upper right) portions of the city. Numerous parks are visible as green patches interspersed within the red-roofed urban region. A region of cultivated fields in the western portion of the city (image center) is a recreational farming area known as the Atatürk Forest Farm and Zoo—an interesting example of intentional preservation of a former land use within an urban area.

View larger image for ISS019-E-11922
ISS019-E-11922
Mauna Kea: The island of Hawaii is home to four volcanoes monitored by volcanologists: Mauna Loa, Hualalai, Kilauea, and Mauna Kea. Mauna Kea is depicted in this astronaut photograph; of the four volcanoes, it is the only one that has not erupted during historical times. The Hawaiian Islands chain, together with the submerged Emperor chain to the northwest, forms an extended line of volcanic islands and seamounts that is thought to record passage of the Pacific Plate over a hotspot (or thermal plume) in the Earth's mantle. Areas of active volcanism in the southern Hawaiian Islands today mark the general location of the hotspot.

This detailed astronaut photograph illustrates why the volcano is called Mauna Kea (white mountain in Hawaiian). While the neighboring Mauna Loa volcano is a classic shield volcano comprised of dark basaltic lava flows, Mauna Kea experienced more explosive activity during its last eruptive phase. This covered its basalt lava flows with pyroclastic deposits. In addition, former glaciers at the summit of the volcano left till deposits—sediments deposited directly in place as the glacial ice melted. The majority of these deposits are visible as light brown areas to the north and southeast of the white snow at image center. Numerous small red to dark gray cinder cones are another distinctive feature of Mauna Kea. The cinder cones represent the most recent type of volcanic activity at the volcano.

View larger image for ISS019-E-10556
ISS019-E-10556
Circles in Thin Ice, Lake Baikal, Russia: Late in April 2009, astronauts aboard the International Space Station observed a strange circular area of thinned ice in the southern end of Lake Baikal in southern Siberia. Siberia is remote and cold; ice cover can persist into June. The upper image, a detailed astronaut photograph, shows a circle of thin ice (dark in color, with a diameter of about 4.4 kilometers); this is the focal point for ice break up in the very southern end of the lake. A sequence of MODIS images indicates that the feature was first visible on April 5, 2009.

Baikal contained another, very similar circle near the center of the lake above a submarine ridge that bisects the lake (ice circles are indicated by arrows in the lower MODIS image from April 20). Both circles are visible through April 20, 2009. Clouds cover the center of the lake until April 24, at which point the circular patch of thin ice was becoming a hole of open water. Similar circular ice patterns—although not nearly as distinct—have been documented in the same central area of the lake in April 1994 (during the STS-59 Shuttle mission) and in 1985 (during the STS-51B Shuttle mission).

While the origin of the circles is unknown, the peculiar pattern suggests convection (upwelling) in the lake’s water column. Ice cover changes rapidly at this time of year. Within a day, the ice can melt almost completely and freeze again overnight. Throughout April, the circles are persistent: they appear when ice cover forms, and then disappear as ice melts. The pattern and appearance suggest that the ice is quite thin. The features were last observed in MODIS images on April 27, 2009.

What can cause convection, bringing warmer waters to the surface? Hydrothermal activity and high heat flow have been observed in other parts of the lake, but the location of this circle near the southern tip, over relatively deep water, is puzzling.

Lake Baikal is unique in many regards. It is the largest (by volume) and deepest (1,637 meters at the deepest point) fresh water lake on Earth and, as a World Heritage Site, it is considered one of Russia’s environmental jewels. It is also one of the world’s oldest lakes (25-30 million years old); sediment deposited on the bottom is up to 7 kilometers deep. The lake’s long, thin, and deep shape results from its location in the Baikal Rift Valley.

As a United Nations World Heritage Site, Lake Baikal is considered one of Russia’s environmental jewels. It is home to an amazing array of plants and animals, many of them unique to the ecosystem. The lake’s biodiversity includes fresh water seals and several species of fish that are not found elsewhere on Earth.

View larger image for ISS019-E-14473
ISS019-E-14473
Solar Evaporation Ponds, Atacama Desert: Brightly colored solar evaporation (salt) ponds in a desert landscape give this astronaut photo an unreal quality. The ponds sit near the foot of a long alluvial fan in the Pampa del Tamarugal, the great hyper-arid inner valley of Chile’s Atacama Desert. The alluvial fan sediments are dark brown, and they contrast sharply with tan sediments of the Pampa del Tamarugal.

Nitrates and many other minerals are mined in this region. A few extraction pits and ore dumps are visible at upper left. Iodine is one of the products from mining; it is first extracted by heap leaching. Waste liquids from the iodine plants are dried in the tan and brightly colored evaporation ponds to crystallize nitrate salts for collection. The recovered nitrates are mainly used for fertilizer for higher-value crops. They are also used in the manufacture of pharmaceuticals, explosives, glass, and ceramics, as well as in water treatment and metallurgical processes.

View larger image for ISS019-E-7720
ISS019-E-7720
Three Gorges Dam, China: A new reservoir is filling in central China. The Three Gorges Dam on the Yangtze River—the world’s largest dam—was completed in 2006, and the river is filling up its valley behind the dam to form a narrow reservoir extending more than 600 kilometers. This image from April 15, 2009, is one of the first images that astronauts on the International Space Station have been able to capture of the flooding behind the dam. The main objective for the dam is to supply water for the largest hydroelectric plant in the world and to help control the devastating floods that plague the lowlands downstream from the dam.

The epic scale of the dam project is matched by the level of controversy it continues to generate. Concerns about major environmental impacts, the relocation of 1.2 million people, and the flooding of 13 cities, more than 1300 villages, archeological locations, and hazardous waste dumps were raised throughout the planning and implementation. Environmental concerns include increased seismicity from the loading of the water, landslides, changed ecosystems, accumulated pollution, increased chances for waterborne diseases, and salinity changes in the Yangtze estuary.

View larger image for ISS019-E-14918
ISS019-E-14918
Saint Helena Island: Saint Helena Island, located in the South Atlantic Ocean approximately 1,860 kilometers (1,156 miles) west of Africa, was one of the many isolated islands that naturalist Charles Darwin visited during his scientific voyages in the nineteenth century. He visited the island in 1836 aboard the HMS Beagle, recording observations of the plants, animals, and geology that would shape his theory of evolution. This image was acquired by astronauts onboard the International Space Station as part of an ongoing effort (the HMS Beagle Project to document current biodiversity in areas visited by Charles Darwin.

This astronaut photograph shows the island’s sharp peaks and deep ravines; the rugged topography results from erosion of the volcanic rocks that make up the island. The change in elevation from the coast to the interior creates a climate gradient. The higher, wetter center is covered with green vegetation, whereas the lower coastal areas are drier and hotter, with little vegetation cover. Human presence on the island has also caused dramatic changes to the original plants and animals of the island. Only about 10 percent of the forest cover observed by the first explorers now remains in a semi-natural state, concentrated in the interior highlands.

Saint Helena Island is perhaps best known as the final resting place of Napoleon Bonaparte I of France. Bonaparte was exiled to the island following his defeat at the Battle of Waterloo in 1815; he died on the island six years later in 1821. Today, the island is a British Overseas Territory, with access provided thirty times a year by a single ship, the Royal Mail Ship St. Helena.

View larger image for ISS019-E-5286
ISS019-E-5286
Mount Fuji, Japan: The 3,776-meter-high Mount Fuji Volcano, located on the island of Honshu in Japan, is one of the world’s classic examples of a stratovolcano. The volcano’s steep, conical profile is the result of numerous layers of lava and debris from explosive eruptions, including ash, cinders, and volcanic bombs, that build up over time. The steep profile is possible because of the relatively high viscosity (stickiness) of the lava typically associated with stratovolcanoes. The high viscosity leads to thick sequences of lava flows near the eruptive vent that build the cone structure. (Low-viscosity flows spread out over the landscape and build lower-profile shield volcanoes.)

Mount Fuji, or Fuji-san in Japanese, is actually comprised of several overlapping volcanoes that began erupting in the Pleistocene Epoch (1.8 million to approximately 10,000 years ago). The currently active volcano, known as Younger Fuji, began forming approximately 11,000 to 8,000 years ago. The most recent explosive activity occurred in 1707, creating Hoei Crater on the southeastern flank of the volcano (image center). This eruption deposited ash on Edo (present-day Tokyo), 95 kilometers to the northeast. No further eruptions have occurred at Mount Fuji, but steam was observed at the summit from 1780–1820, and the volcano is considered active.

This oblique (viewed at an angle, rather than straight down) astronaut photograph illustrates the snow-covered southeastern flank of the volcano.

< Previous 1 Next >
This server is scheduled to be off starting the evening of Thursday October 10 and ending the morning of Tuesday October 15 to accommodate a scheduled power outage.