Crossing the Sahara wastes in orbit on Columbia, our crew captured this view of the Pic Tousside volcano, using a 250mm lens on a Hasselblad 70mm film camera. The volcano is an eye-catching landmark on the way from Morocco to the Nile Valley. Note the numerous cinder cones at the top of the photo on the mountain slopes; the black basalt lava flows are running downhill, of course.
NASA’s Earth Observatory site says the following:
The Tibesti Mountain Range in northern Chad is one of the world’s least-studied volcanic regions. A look at the area from space, however, must intrigue volcanologists. One of the Tibesti Mountain’s features is Tarso Toussidé.
Looking like the result of a giant inkwell tipped on its side, Tarso Toussidé underwent a violent eruption in the recent geologic past, and the remains of that eruption have stained the ground black. The volcano ejected tephra, fragments of rock and volcanic glass, lava, and ash. Tephra does not last on the landscape as long as consolidated volcanic rocks such as tuff or lava, so the presence of tephra suggests fairly recent activity. In the middle of the field of dark tephra is Pic Toussidé, a lava dome poking out of the current caldera.
Volcanoes often sport multiple calderas, particularly as the primary site for eruptive activity shifts over time. East of Pic Toussidé are two calderas, the southern one bearing a white splotch roughly 2 kilometers long. This white color could result from salt. Water pooling in the caldera would not have an outlet, and as the water evaporated, minerals such as salt would be left behind.
My Columbia crewmates and I took this shot on STS-80 with a 70mm Hasselblad film camera using a 100mm lens. On December 5, 1996, our altitude over the northeastern plains of India was about 185 nm. Master geologist and astronaut instructor Bill Muehlberger wrote the caption above; Bill helped teach the Apollo astronauts their geology skills, and he took my Hairball astronaut class to the field in New Mexico to teach similar lessons. At the southern base of the Himalaya (bottom center) is the Brahmaputra River, flowing from east to west (right to left) on its way to join the Ganges. The Brahmaputra River (also called as “Burlung-Buthur” by the Bodo people of Assam), called Yarlung Tsangpo in Tibetan language, originates on the Chemayungdung Glacier located on the northern side of the Himalayas in Tibet. The river is 3,848 km (2,391 mi) long. The river flows around and through the eastern ranges of the Himalaya and returns in the lower part of the photo, flowing to the west, to join the Ganges.
The Tibetan Plateau is the tan area at upper left. The spidery lake at left edge of the photo is Yamzha Yumco. Lhasa, Tibet lies just to the north. The Jiali tectonic fault slashes across Tibet from upper left to right. At far right center, the Brahmaputra emerges from the mountain front and carries an immense load of silt and sand toward the Bay of Bengal in the Indian Ocean. Geologists estimate that the Brahmaputra transports approximately 13 million tons of suspended sediment per day during floods. This is one corner of the world where erosion is tearing the Himalaya down almost as fast as they are pushed skyward.
This STS-80 Columbia image, shot with a 250mm lens on a Hasselblad 70mm body, shows one of our favorite Sahara targets, the Aorounga impact crater, which may be a chain of 3 circular impact craters. Radar images from STS-59, Space Radar Lab 1 (April 1994, my first mission), revealed what looks like two smaller craters to the northeast. This entire frame is about 25 miles across.
From NASA’s Earth Observatory: Aorounga Impact Crater is located in the Sahara Desert, in north-central Chad, and is one of the best-preserved impact structures in the world. The crater is thought to be middle or upper Devonian to lower Mississippian (approximately 345–370 million years old) based on the age of the sedimentary rocks deformed by the impact. Spaceborne Imaging Radar (SIR) data collected in 1994 suggests that Aorounga is one of a set of three craters formed by the same impact event. The other two suggested impact structures are buried by sand deposits.
The concentric ring structure of the Aorounga crater—renamed Aorounga South in the multiple-crater interpretation of SIR data—is clearly visible in this detailed astronaut photograph. The central highland, or peak, of the crater is surrounded by a small sand-filled trough; this in turn is surrounded by a larger circular trough. Linear rock ridges alternating with light orange sand deposits cross the image from upper left to lower right; these are called yardangs by geomorphologists. Yardangs form by wind erosion of exposed rock layers in a unidirectional wind field. The wind blows from the northeast at Aorounga, and sand dunes formed between the yardangs are actively migrating to the southwest.
We took this image from Columbia on November 24, 1996, from an altitude of 188 nautical miles. Mount Pinatubo is an active stratovolcano on the island of Luzon, in the Philippines. On all my flights (which all came after the 1991 eruption), I’ve observed the downhill migration of volcanic ash from the summit and its crater lake. The crater lake and mud flows are seen very well here, after the 1996 monsoon season. Note the now-closed Clark Air Force Base (and now reopened commercial airport) on the plains at lower right.
From Wikipedia: Before 1992, Pinatubo was heavily eroded, inconspicuous, and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous Aetas people.
The volcano’s eruption on June 15, 1991 produced the second largest terrestrial eruption of the 20th century (after the 1912 eruption of Novarupta in the Alaska Peninsula). Complicating the eruption was the arrival of Typhoon Yunya (Diding), bringing a lethal mix of ash and rain to areas surrounding the volcano. Predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives. Surrounding areas were severely damaged by pyroclastic flows, ash deposits, and, subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits. This caused extensive destruction to infrastructure and changed river systems for years after the eruption.
The volcano’s Plinian / Ultra-Plinian eruption on June 15, 1991 produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula. Complicating the eruption was the arrival of Typhoon Yunya (Diding), bringing a lethal mix of ash and rain to areas surrounding the volcano. Predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives. Surrounding areas were severely damaged by pyroclastic flows, ash deposits, and, subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits. This caused extensive destruction to infrastructure and changed river systems for years after the eruption.
NASA text by my colleague, volcanologist Dr. Cindy Evans: In early 1991, Mt. Pinatubo, a volcano north of Manila on the Philippine island of Luzon, had been dormant for more than 500 years. Few geologists would have guessed that it would produce one of the world’s most explosive eruptions in the twentieth century. Indications of unrest started a few months before the June 1991 eruption, but the size and impact of the eruption were completely unexpected. During the June 12-15 eruptive climax, the top of the mountain was blown off, lowering the elevation by roughly 150 m. About 8 to 10 km2 of material (Scott, et al., 1996) spewed out of the volcano onto the surrounding slopes. The eruption forced evacuation of more than 50,000 people, and effectively shut down two major US military bases (Clark Air Force Base and Subic Bay Naval Base); it was ultimately responsible for taking several hundred human lives.
Before the eruption, Mt. Pinatubo was a forested, deeply dissected and unimposing mountain on Luzon’s Bataan Peninsula. Although the upper slopes were steep and not well suited for agriculture, the lower slopes were heavily populated and supported extensive rice fields.
During the eruption, the upper slopes of the mountain suffered immediate destruction. The climactic explosions of June 14–16, 1991, blasted away the summit of Pinatubo, blew down surrounding forests, and rained hundreds of cubic meters of loose sand and gravel down on the mountain’s upper slopes. Floods of hot volcanic slurries were responsible for long-lasting damage downslope.
Astronauts did not observe the June 1991 eruption of the volcano—but they have routinely monitored subsequent changes around Mt. Pinatubo. The eruption had two major environmental effects which are readily documented from low-Earth orbit: the distribution of vast quantities of sulfur dioxide aerosols into the stratosphere; and the post-eruption mudflows, or lahars, which are recognized as the major natural hazard from the eruption.
This image of Ayers Rock and the Olgas (Uluru and Kata Tjuta) and the surrounding terrain was captured by the crew of space shuttle Columbia during the STS-80 mission; it was taken on Dec. 6, 1996, from an altitude of 202 nautical miles. We always looked for a chance to shoot Uluru on our passes over Australia, and this was a particularly nice pass, captured with a 100mm Hasselblad lens on 70mm film. I trained for both my Space Radar Lab missions at Ayers Rock and the Olgas with a NASA team flying the agency’s DC-8 aircraft out of nearby Alice Springs. Fellow STS-59 astronaut Linda Godwin and I drove 5 hours from Alice Springs to visit these famous rock formations. In this image, Uluru is at right, with Kata Tjuta and its highest promontory, Mt. Olga, on the left. Lake Amadeus is at top.
From NASA’s “Visible Earth” website: Seen from ground level, this majestic sandstone rock formation stands 348 meters (1,120 feet) tall and is 3 kilometers (1.85 miles) long. Uluru is the ancient name used by Indigenous Australians; Ayers Rock is the name that was given to the landform by explorer William Christie Gosse in the 1800s. Uluru is one of Australia’s major tourist attractions (more than 270,000 visitors in 2014), with operations run by people from the small town of Mutitjulu. A 16-kilometer (10-mile) road circles the rock, and a disused airstrip lies near the town.
Uluru and a similar striking landform known as Kata Tjuta (Mount Olga) are part of the Uluru-Kata Tjuta National Park, created as a UNESCO site in 1994 for cultural preservation and protection. Uluru and Kata Tjuta are remnants of sediments eroded from an ancient mountain range that existed about 550 million years ago. The sediments were subsequently buried and compressed to form harder rocks—called arkose and conglomerate by geologists. These rocks were later tilted from their original horizontal orientation by powerful tectonic forces. Views from above now clearly show the hundreds of originally flat-lying layers that make up Uluru. Softer and younger sedimentary rocks were then eroded away, leaving the more resistant rocks exposed to form the present-day landforms.
Uluru is thought by native peoples to have been created by ancestral beings during the Dreamtime, which has been described as the essence of aboriginal culture and spirituality. The rock is regarded as one of the ancestors’ most impressive pieces of work. Ancient paintings throughout its caves and fissures describe this relationship, keeping Dreamtime traditions alive. The proximity of the Mutitjulu settlement to the rock symbolizes the spiritual connection between the local people and Uluru.
From NASA’s Earth Observatory website: In the heart of the Australian Outback, a massive block of red sandstone rises up out of the near-perfect flatness of the eroded landscape. Called Uluru, or Ayer’s Rock, this giant is a monolith 348 meters (1,142 feet) high, 3.6 kilometers (2.2 miles) long, and 9.4 kilometers (5.8 miles) around. It is the largest single rock known in the world. Tourists come from all over the country and the world to watch sunrise and sunset bring the colors of the rock to life.
Centered in the scene, Uluru appears a more subdued orange-red than the surrounding desert soils. These reddish soils and their location in the heart of the Outback give rise to the region’s nickname as Australia’s “Red Center.” Trees and other vegetation surround the base of the rock, giving the impression of streams of turquoise waters flowing out of the rock. The rock is carved and scoured by eons of erosion by wind and water. To the Aboriginal people, many of these features are part of the religious mythology through which they describe their existence and history in the region.
…Located in the Northern Territory of Australia, Uluru-Kata Tjuta National Park hosts some of the world’s most spectacular examples of inselbergs, or isolated mountains. The most famous of these inselbergs is Uluru (also known as Ayers Rock). An equally massive inselberg located approximately 30 kilometers (20 miles) to the northwest is known as Kata Tjuta. Like Uluru, this is a sacred site to the native Anangu or Aboriginal people. An English-born explorer named the highest peak Mount Olga, with the entire grouping of rocks informally known as “the Olgas.” Mount Olga has a peak elevation of 1,069 meters (3,507 feet) above sea level, making it 206 meters (676 feet) higher than Uluru.
Kata Tjuta is comprised of gently dipping Mount Currie Conglomerate, a sedimentary rock that includes rounded fragments of other rock types (here, primarily granite with less abundant basalt and rhyolite in a coarse sandy matrix). Geologists interpret the Mount Currie Conglomerate as a remnant of a large fan of material rapidly eroded from mountains uplifted approximately 550 million years ago. Subsequent burial under younger sediments consolidated the eroded materials to form the conglomerate exposed at the surface today.
Runways of the shuttle landing facility (top center) and Cape Canaveral Air Force Station’s “Skid Strip” (near the tip of Cape Canaveral) are visible. At top center are the shuttle launch pads, 39A and 39B; we launched from Pad 39B (northernmost/topmost pad). Indian River is at left, the Banana River at right, next to the Cape. The old ICBM Row launch pads (Mercury and Gemini) are clearly visible north of Cape Canaveral. I left Earth four times from this place–pretty special.
Monterrey is the capital and largest city of the northeastern state of Nuevo León, in Mexico. The city is anchor to the third-largest metropolitan area in Mexico and is ranked as the ninth-largest city in the nation. Monterrey is located in northeast Mexico, at the foothills of the Sierra Madre Oriental.
Monterrey Image Caption (NASA): Potrero Garcia and Potrero La Mula are breached salt-cored folds immediately north of the Sierra Madre Oriental and Monterrey. [Portrero Garcia is the triangular formation at upper left.–TJ] Individual limestone layers can be resolved in this beautifully detailed view, as can the tilt of the layers outward from the center of the fold (anticline). Most of the salt has been eroded from the core of the structure, but what remains is now being mined. In Las Grutas de Garcia (Garcia Caverns) the limestone bedrock has been dissolved and both limestone and gypsum formations decorate the cave.
Our STS-80 crew took this shot of Great Exuma Island and the Tongue of the Ocean on Dec. 3, 1996, from 185 nautical miles above the Bahamas. This is one of the loveliest ocean areas visible to orbiting astronauts.
A NASA caption says: This extraordinary image captures the meeting place of the deep waters of the Tongue of the Ocean and the much shallower, completely submerged Grand Bahama Bank. This platform reef drops off quickly into the branch of the Great Bahama submarine canyon that because of its shape is called the Tongue of the Ocean. The vertical rock walls of the Canyon rise 14,060 feet from their greatest depth to the surrounding seabed, which is why the water is so dark in color compared to the reef. The shallowest parts of the reef are no more than three to seven feet deep; so shallow, in fact, that in the northeast corner of the image you can zoom in and see large wave-sized ripples of sand on the bottom. Like so many other biological structures, the ribbon-like form of the reef maximizes surface area and thus the number of organisms that can colonize the structure. The closest land is the Bahama Islands of Great Exuma, less than 16 miles to the east [right side of the image], and Andros about 27 miles to the west.
From 187 nautical miles up, our Columbia crew imaged the island of Maui and Kahoolawe (lower left) on Nov. 25, 1996. Lanai is to the far left. The West Maui volcano is under clouds, but the sharply incised ravines running down to Lahaina and Kanaapali Beach show how much rainfall the mountain intercepts. Central Maui is clear, as are the resorts along the west-facing South Maui coast. Kahului airport is visible on the north central coast. The green slopes of Haleakala volcano (dormant) are visible at right. Haleakala National Park includes the volcano’s summit, at about 10,000 feet. A line of cinder cones follows the southwest rift zone up to the summit; darker, more recent lava flows mark the site of the most recent eruption on Maui, just before 1800 on the southwest tip of the island opposite Kaho’olawe. Haleakala’s summit caldera has been heavily eroded by heavy rains, creating a wide summit valley that drains both to the south, north, and east.
NASA’s Earth Observatory says:
In 1907, writer Jack London scaled a towering mountain in eastern Maui, the second largest of the Hawaiian Islands. When he reached the top and looked east, he was confronted with an otherworldly scene. “Far above us was the heaven-towering horizon, and far beneath us, where the top of the mountain peak should have been, was a deeper deep, the great crater, the House of the Sun,” London wrote. “The tie-ribs of earth lay bare before us. It was a workshop of nature still cluttered with the raw beginnings of world-making.”
That is not to say the area is not rich with signs of volcanic activity. “This floor, broken by lava flows, and cinder cones, was as red and fresh and uneroded as if were but yesterday that the fires went out,” London noted. “The cinder-cones, the smallest over four-hundred feet in height and the largest over nine-hundred, seemed no more than puny little sand hills, so mighty was the magnitude of the setting.”
…There is less vegetation in the valley—which comprises much of the national park—than to the north and east of the mountain because the valley lies in a rain shadow. Prevailing winds drop rain on the eastern and northern sides of the mountains because moisture gets squeezed from the air as it flows up and over the slopes. The cinder cones—steep conical hills around volcanic vents—appear as small mounds in the middle of the valley.
While London was correct that the lava flows are young, his time scale was a bit off. According to the U.S. Geological Survey, radiocarbon dating suggestions that the most recent eruption occurred between 1480 and 1600. The oldest exposed flows are 1.1 million years old, though geologists think the shield volcano began building itself up about two million years ago.
Haleakalā National Park was created on August 1, 1916, as part of Hawaii National Park. At that time, the park also included Kilauea and Mauna Loa. However, in 1961, the volcanoes of Hawaii and Maui were separated into different parks. The name Haleakalā is Hawaiian for “House of the Sun.” In Hawaiian mythology, a god named Maui climbed the mountain and lassoed the Sun’s rays to lengthen the day.
Our photo from STS-80 shows the lower tip of the Sinai Peninsula in Egypt. Mt.Sinai is just to the right of upper center amid a welter of crustal faults. Mount Sinai is a 2,285-metre (7,497 ft) moderately high mountain near the city of Saint Catherine in the Sinai region. It is next to Mount Catherine (at 2,629 m or 8,625 ft, the highest peak in Egypt). It is surrounded on all sides by higher peaks of the mountain range. (Wiki) North is at top right.
From NASA’s caption: Low sun angle and excellent focus reveal details of three prominent sets of faults and fractures (and subordinate ones) in the 500-600-million-year-old bedrock of the Sinai Peninsula. Displacement as great as 4000 m is documented on faults in the southwest. Younger, more northerly faults crosscut those of northeasterly and northwesterly trend; the younger faults reflect a change in the direction of extension in the Red Sea rift from NE (55 degrees) at ~25 million years ago to almost N (10-20 degrees) at present.