Hydraotes Chaos is a broken-up region in the Oxia Palus quadrangle of Mars, located at 0.8° North and 35.4° West. It was named after a classical albedo feature name. More information and more examples of chaos regions can be found at Martian chaos terrain; the area contains small conical edifices, called Hydraotes Colles, which were interpreted as the Martian equivalent of terrestrial cinder cones formed by volcanic activity. Chaos terrain Geology of Mars HiRISE List of areas of chaos terrain on Mars Martian chaos terrain
A stratovolcano known as a composite volcano, is a conical volcano built up by many layers of hardened lava, tephra and ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas; the lava flowing from stratovolcanoes cools and hardens before spreading far, due to high viscosity. The magma forming this lava is felsic, having high-to-intermediate levels of silica, with lesser amounts of less-viscous mafic magma. Extensive felsic lava flows have travelled as far as 15 km. Stratovolcanoes are sometimes called "composite volcanoes" because of their composite stratified structure built up from sequential outpourings of erupted materials, they are in contrast to the less common shield volcanoes. Two famous examples of stratovolcanoes are Krakatoa, known for its catastrophic eruption in 1883 and Vesuvius, whose eruption in AD79 caused destruction of Pompeii and Herculaneum in 79 AD.
Both eruptions claimed thousands of lives. In modern times, Mount St. Helens and Mount Pinatubo have erupted catastrophically, with lesser losses of lives; the possible existence of stratovolcanoes on other terrestrial bodies of the Solar System has not been conclusively demonstrated. The one feasible exception are the existence of some isolated massifs on Mars, for example the Zephyria Tholus. Stratovolcanoes are common at subduction zones, forming chains and clusters along plate tectonic boundaries where oceanic crust is drawn under continental crust or another oceanic plate; the magma forming stratovolcanoes rises when water trapped both in hydrated minerals and in the porous basalt rock of the upper oceanic crust is released into mantle rock of the asthenosphere above the sinking oceanic slab. The release of water from hydrated minerals is termed "dewatering", occurs at specific pressures and temperatures for each mineral, as the plate descends to greater depths; the water freed from the rock lowers the melting point of the overlying mantle rock, which undergoes partial melting and rises due to its lighter density relative to the surrounding mantle rock, pools temporarily at the base of the lithosphere.
The magma rises through the crust, incorporating silica-rich crustal rock, leading to a final intermediate composition. When the magma nears the top surface, it pools in a magma chamber within the crust below the stratovolcano. There, the low pressure allows water and other volatiles dissolved in the magma to escape from solution, as occurs when a bottle of carbonated water is opened, releasing CO2. Once a critical volume of magma and gas accumulates, the plug of the volcanic vent is broken, leading to a sudden explosive eruption. In recorded history, explosive eruptions at subduction zone volcanoes have posed the greatest hazard to civilizations. Subduction-zone stratovolcanoes, such as Mount St. Helens, Mount Etna and Mount Pinatubo erupt with explosive force: the magma is too stiff to allow easy escape of volcanic gases; as a consequence, the tremendous internal pressures of the trapped volcanic gases remain and intermingle in the pasty magma. Following the breaching of the vent and the opening of the crater, the magma degasses explosively.
The magma and gases blast out with full force. Since 1600 CE, nearly 300,000 people have been killed by volcanic eruptions. Most deaths were caused by pyroclastic flows and lahars, deadly hazards that accompany explosive eruptions of subduction-zone stratovolcanoes. Pyroclastic flows are swift, avalanche-like, ground-sweeping, incandescent mixtures of hot volcanic debris, fine ash, fragmented lava and superheated gases that can travel at speeds in excess of 160 km/h. Around 30,000 people were killed by pyroclastic flows during the 1902 eruption of Mount Pelée on the island of Martinique in the Caribbean. In March to April 1982, three explosive eruptions of El Chichón in the State of Chiapas in southeastern Mexico, caused the worst volcanic disaster in that country's history. Villages within 8 km of the volcano were destroyed by pyroclastic flows, killing more than 2,000 people. Two Decade Volcanoes that erupted in 1991 provide examples of stratovolcano hazards. On June 15, Mount Pinatubo spewed an ash cloud 40 km into the air and produced huge pyroclastic surges and lahar floods that devastated a large area around the volcano.
Pinatubo, located in Central Luzon just 90 km west-northwest from Manila, had been dormant for 6 centuries before the 1991 eruption, which ranks as one of the largest eruptions in the 20th century. In 1991, Japan's Unzen Volcano, located on the island of Kyushu about 40 km east of Nagasaki, awakened from its 200-year slumber to produce a new lava dome at its summit. Beginning in June, repeated collapse of this erupting dome generated ash flows that swept down the mountain's slopes at speeds as high as 200 km/h. Unzen is one of more than 75 active volcanoes in Japan; the eruption of Mount Vesuvius in 79 smothered the nearby ancient cities of Pompeii and Herculaneum with thick deposits of pyroclastic surges and lava flows. Although death toll is estimated between 13,000 and 26,000 remains, the exact number still remains unknown. Vesuvius is recognized as one of the most dangerous volcanoes, due to its
Scoria is a vesicular, dark colored volcanic rock that may or may not contain crystals. It is dark in color, basaltic or andesitic in composition. Scoria is low in density as a result of its numerous macroscopic ellipsoidal vesicles, but in contrast to pumice, all scoria has a specific gravity greater than 1, sinks in water; the holes or vesicles form when gases that were dissolved in the magma come out of solution as it erupts, creating bubbles in the molten rock, some of which are frozen in place as the rock cools and solidifies. Scoria may form as part of a lava flow near its surface, or as fragmental ejecta, for instance in Strombolian eruptions that form steep-sided scoria cones. Most scoria is composed of glassy fragments, may contain phenocrysts; the word scoria comes from the Greek skōria, rust. A colloquial term for scoria is cinder. Scoria differs from pumice, another vesicular volcanic rock, in having larger vesicles and thicker vesicle walls, hence is denser; the difference is the result of lower magma viscosity, allowing rapid volatile diffusion, bubble growth and bursting.
As rising magma encounters lower pressures, dissolved gases are able to form vesicles. Some of the vesicles are trapped when the magma solidifies. Vesicles are small, spheroidal and do not impinge upon one another. Volcanic cones of scoria can be left behind after eruptions forming mountains with a crater at the summit. An example is Maungarei in New Zealand, which like Te Tatua-a-Riukiuta in the south of the same city has been extensively quarried. Quincan, a unique form of Scoria, is quarried at Mount Quincan in Australia. Scoria has several useful characteristics, it is somewhat porous, has high surface area and strength for its weight, has striking colours. Scoria is used in landscaping and drainage works, it is commonly used in gas barbecue grills. Scoria can be used for high-temperature insulation. Scoria is used on oil well sites to limit mud issues with heavy truck traffic; the quarry of Puna Pau on Rapa Nui/Easter Island was the source of a red-coloured scoria which the Rapanui people used to carve the pukao for their distinctive moai statues, to carve some moai from.
It is used as a traction aid on ice- and snow-covered roads. Cinder – Pyroclastic vesicular rock Tuff – Rock consolidated from volcanic ash Pumice – Light coloured vesicular volcanic glass Volcano – A rupture in the crust of a planetary-mass object that allows hot lava, volcanic ash, gases to escape from a magma chamber below the surface List of rock types – A list of rock types recognized by geologists Rock – A occurring solid aggregate of one or more minerals or mineraloids
Capulin Volcano National Monument
Capulin Volcano National Monument is a U. S. National Monument located in northeastern New Mexico that protects and interprets an extinct cinder cone volcano, part of the Raton-Clayton Volcanic Field. A paved road spirals around the volcano and visitors can drive up to a parking lot at the rim. Hiking trails circle the rim as well as lead down into the mouth of the volcano; the monument is administered by the National Park Service. The visitor center features exhibits about the volcano and the area's geology and cultural history, offers educational programs about volcanoes. There is a video presentation about the volcano; the name capulin comes from a type of black cherry, Prunus virginiana, native to southern North America. Apollo 16's John Young and Charlie Duke did some of their geologic training here in May 1971. William R. Muehlberger was one of the geology instructors. From the National Park Service: Capulin Volcano National Monument is a well-preserved young, symmetrical cinder cone, it rises steeply from the surrounding grassland plains to an elevation of 8,182 feet above sea level.
The irregular rim of the crater is about a mile in the crater about 400 feet deep. Capulin Volcano is one of the outstanding landmarks located in the northeast corner of New Mexico, where the rolling grasslands meet the foothills of the Sangre de Cristo Mountains. Capulin Volcano's highest point provides unobstructed, panoramic views of the volcanic field, distant snow-capped mountains, portions of five states. Capulin Volcano offers visitors excellent opportunities for observing and understanding volcanic formation; the large volcanic field surrounding the monument contains at least 100 recognizable volcanoes, aids visitors in gaining insights into 10 million years of the geological history of northern New Mexico. According to the National Park Service:On January 16, 1891, Capulin Mountain was …withdrawn from settlement, entry or other disposition under any of the public land laws, until such time as Congress may see fit to take action touching the same or until otherwise ordered by competent authority… On August 9, 1916, President Woodrow Wilson set Capulin aside as a U.
S. National Monument by Presidential Proclamation No. 1340, to preserve "…a striking example of recent extinct volcanoes … which …is of great scientific and geologic interest…" Public Law 87-635, 87th Congress, S.2973, September 5, 1962, amended the proclamation to "…preserve the scenic and scientific integrity of Capulin Mountain National Monument…" because of the significance of Capulin Volcano. On December 31, 1987, Congress changed the Monument's name from Capulin Mountain National Monument to Capulin Volcano National Monument by Public Law 100-225. Sierra Grande to the southeast Johnson Mesa to the northwest Eastern New Mexico Black Mesa to the northeast nps.gov: official Capulin Volcano National Monument website — NPS - National Park Service. Sangres.com: Information and photos NPS — "Geology Fieldnotes: Capulin Volcano National Monument"
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are found where tectonic plates are diverging or converging, most are found underwater. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can form where there is stretching and thinning of the crust's plates, e.g. in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "plate hypothesis" volcanism. Volcanism away from plate boundaries has been explained as mantle plumes; these so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth.
Volcanoes are not created where two tectonic plates slide past one another. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere. Volcanic winters have caused catastrophic famines; the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is sometimes spelled vulcanology. At the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock; because the crust is thin at these ridges due to the pull of the tectonic plates, the release of pressure leads to adiabatic expansion and the partial melting of the mantle, causing volcanism and creating new oceanic crust.
Most divergent plate boundaries are at the bottom of the oceans. Black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed. Subduction zones are places where two plates an oceanic plate and a continental plate, collide. In this case, the oceanic plate subducts, or submerges, under the continental plate, forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the melting temperature of the overlying mantle wedge, thus creating magma; this magma tends to be viscous because of its high silica content, so it does not attain the surface but cools and solidifies at depth. When it does reach the surface, however, a volcano is formed. Typical examples are the volcanoes in the Pacific Ring of Fire. Hotspots are volcanic areas believed to be formed by mantle plumes, which are hypothesized to be columns of hot material rising from the core-mantle boundary in a fixed space that causes large-volume melting.
Because tectonic plates move across them, each volcano becomes dormant and is re-formed as the plate advances over the postulated plume. The Hawaiian Islands are said to have been formed in such a manner; this theory, has been doubted. The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit; the features of volcanoes are much more complicated and their structure and behavior depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have landscape features such as massive plateaus. Vents that issue volcanic material and gases can develop anywhere on the landform and may give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Hawaii's Kīlauea. Other types of volcano include cryovolcanoes on some moons of Jupiter and Neptune. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes except when the mud volcano is a vent of an igneous volcano.
Volcanic fissure vents are linear fractures through which lava emerges. Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent, they do not explode catastrophically. Since low-viscosity magma is low in silica, shield volcanoes are more common in oceanic than continental settings; the Hawaiian volcanic chain is a series of shield cones, they are common in Iceland, as well. Lava domes are built by slow eruptions of viscous lava, they are sometimes formed within the crater of a previous volcanic eruption, as in the case of Mount Saint Helen
A cinder is a pyroclastic material. Cinders are extrusive igneous rocks. Cinders are similar to pumice, which has so many cavities that its low density of 0.641g/cm^3 allows it to float in water. Cinder is brown, black, or red depending on its chemical content. A more modern name for cinder is scoria; the following geologic characteristics define a cinder: Uncemented Vitric Having bubble-like cavities, called vesicles Measuring not less than 2.0 millimeters in at least one dimension Apparent specific gravity between 1.0 and 2.0 Typical cinders are red or black in color. Contain numerous gas bubbles "frozen" into place as magma exploded into the air and cooled quickly. Cinders have been used on track surfaces and roads to provide additional traction in winter conditions. Cinders are employed as inorganic mulch in xeriscaping, because of excellent drainage properties and erosion resistance. In this context, they are referred to with the name "lava rock". Cinder block Cinder cone – A steep conical hill of loose pyroclastic fragments around a volcanic vent Cinder track Lapilli Scoria – Dark vesicular volcanic rock Tephra – Fragmental material produced by a volcanic eruption Ye Olde Cinder House Cinderella
Parícutin is a cinder cone volcano located in the Mexican state of Michoacán, near the city of Uruapan and about 322 kilometers west of Mexico City. The volcano surged from the cornfield of local farmer Dionisio Pulido in 1943, attracting both popular and scientific attention. Paricutín presented the first occasion for modern science to document the full life cycle of an eruption of this type. During the volcano's nine years of activity, scientists sketched and mapped it and took thousands of samples and photographs. By 1952, the eruption had left a 424-meter-high cone and damaged an area of more than 233 square kilometers with the ejection of stone, volcanic ash and lava. Three people were killed, two towns were evacuated and buried by lava, three others were affected. Hundreds of people had to be permanently relocated, two new towns were created to accommodate their migration. Although the larger region still remains active volcanically, Parícutin is now dormant and has become a tourist attraction with people climbing the volcano and visiting the hardened lava-covered ruins of the San Juan Parangaricutiro Church.
In 1997, CNN included Parícutin in its list of the Seven Natural Wonders of the World. Parícutin is located in the Mexican municipality of Nuevo Parangaricutiro, Michoacán, 29 kilometers west of the city of Uruapan and about 322 km west of Mexico City, it lies on the northern flank of the Cerros de Tancítaro, which itself lies on top of an old shield volcano and extends 3,170 meters above sea level and 424 meters above the Valley of Quitzocho-Cuiyusuru, wedged against old volcanic mountain chains and surrounded by small volcanic cones with the intervening valleys occupied by small fields and orchards or small settlements, from groups of a few houses to those the size of towns. The volcano lies on, is a product of, the Trans-Mexican Volcanic Belt, which runs 900 kilometers west-to-east across central Mexico, it includes the Sierra Nevada mountain range as well as thousands of cinder cones and volcanic vents. Volcanic activity here has created the Central Mexican Plateau and rock deposits up to 1.8 kilometers deep.
It has created fertile soils by the widespread deposition of ash and thereby some of Mexico’s most productive farmland. The volcanic activity here is a result of the subduction of the Rivera and Cocos plates along the Middle America Trench. More the volcano is the youngest of the 1,400 volcanic vents of the Michoacán-Guanajuato volcanic field, a 40,000 square kilometers basalt plateau filled with scoria cones like Parícutin, along with small shield volcanoes, tuff rings and lava domes. Scoria cones are the most common type of volcano in Mexico and building a cone-shaped mountain with steep slopes before becoming extinct. Parícutin's immediate predecessor was El Jorullo in Michoacán, which erupted in 1759; the crater of the volcano is about 200 meters across and it is possible to both climb the volcano and walk around the entire perimeter. Although classified as extinct by scientists, Parícutin is still hot, seeping rainwater reacts with this heat so that the cone still emits steam in various streams.
The forces that created the volcano are still active. In 1997 there was a vigorous swarm of 230 earthquakes in the Parícutin area due to tectonic movement, with five above 3.9 on the moment magnitude scale. There were some reports of rumbling in 1995 and of black steam and rumbling in 1998. In the summer of 2006, there was another major volcanic earthquake swarm, with over 300 located near the volcano, indicating magma movement, but with no eruption at Parícutin or anywhere else. Parícutin erupted from 1943 to 1952, unusually long for this type of volcano, with several eruptive phases. For weeks prior, residents of the area reported hearing noises similar to thunder but without clouds in the sky; this sound is consistent with deep earthquakes from the movement of magma. A study indicated that the eruption was preceded by 21 earthquakes over 3.2 in intensity starting five weeks before the eruption. One week prior to the eruption, newspapers reported 25–30 per day; the day before the eruption, the number is estimated at 300.
The eruption began on February 1943, at about 4:00 PM local time. The center of the activity was a cornfield owned near the town of Parícutin. During that day, he and his family had been working their land, clearing it to prepare for spring planting; the ground nearby swelled upward and formed a fissure between 2 and 2.5 meters across. They reported that they heard hissing sounds, smoke which smelled like rotten eggs, indicating the presence of hydrogen sulfide. Within hours, the fissure would develop into a small crater. Pulido reported: At 4 p.m. I left my wife to set fire to a pile of branches when I noticed that a crack, situated on one of the knolls of my farm, had opened... and I saw that it was a kind of fissure that had a depth of only half a meter. I set about to ignite the branches again when I felt a thunder, the trees trembled, I turned to speak to Paula. More smoke began to rise with a hiss or whistle and continuous, he tried to find his family and oxen but they had disappeared so he rode his horse to town where he found his family and friends, happy to see him alive.