Tharsis quadrangle
Encyclopedia
The Tharsis quadrangle
is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey
(USGS) Astrogeology Research Program
. The Tharsis quadrangle is also referred to as MC-9 (Mars Chart-9).
The quadrangle covers the area from 90° to 135° west longitude and 0° to 30° north latitude on Mars
and contains most of the Tharsis Rise
. The plateau is about as high as Earth's Mount Everest and about as big in area as all of Europe. Tharsis contains a group of large volcanoes. Olympus Mons
is the tallest.
is the tallest known volcano in the Solar System; it is 100 times larger than any volcano on Earth. Ascraeus Mons
and Pavonis Mons
are at least 200 miles across and are over six miles above the plateau
that they sit on—and, the plateau is three to four miles above the zero altitude of Mars. Pavonis Mons, the middle in a line of three volcanoes, sits at just about dead center on the equator. Mons is a term used for a large raised feature. Tholus is about the same, but smaller. A patera is flatter and like a volcano with a super large opening. Actually, a patera is formed when the top of a volcano collapses because its magma chamber is empty. Crater Lake
Oregon
was formed that way. Several volcanoes form a straight line in the Tharsis Uplift. Two major ones are in the Tharsus quadrangle: Ascraeus Mons and Pavonis Mons. It has been proposed that these are the result of plate motion which on Earth makes volcanic arc islands.
. Estimates put the amount of gas released to the atmosphere as enough to make the atmosphere thicker than the Earth's. In addition the water vapor from the volcanoes could have made enough water to place all of Mars under 120 meters of water. Of course, we all know that carbon dioxide is a greenhouse gas
. It raises the temperature of a planet by trapping heat in the form of infrared radiation. So the eruption of lava on Tharsis could have made Mars Earth-like in the past. Mars may have once had a much thicker and warmer atmosphere. Oceans and/or lakes may have been present.
, Olympica Fossae
, Ceraunius Fossae
, and Tractus Fossae
. These troughs form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Studies have shown that the volcanoes of Tharsis caused most of the major fossae on Mars. The stress that caused the fossae and other tectonic features is centered in Noctis Labyrinthus
, at 4 S and 253 E. But the center has moved somewhat over time. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes. A trough often has two breaks with a middle section moving down, leaving steep cliffs along the sides; such a trough is called a graben
. Studies have found that on Mars a fault may be as deep as 5 km, that is the break in the rock goes down to 5 km. Moreover, the crack or fault sometimes widens or dialates. This widening causes a void to form with a relatively high volume. When material slides into the void, a pit crater or a pit crater chain forms. Pit craters do not have rims or ejecta around them, like impact craters do. On Mars, individual pit craters can join to form chains or even to form troughs that are sometimes scalloped. Other ideas have been suggested for the formation of fossae and pit craters. There is evidence that they are associated with dikes of magma. Magma might move along, under the surface, breaking the rock and, more importantly, melting ice. The resulting action would cause a crack to form at the surface. Pit craters are not common on Earth. Sinkholes, where the ground falls into a hole (sometimes in the middle of a town) resemble pit craters on Mars. However, on the Earth these holes are caused by limestone
being dissolved thereby causing a void.
Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because they may be reservoirs of water.
, on Ceraunius Fossae
, and on Olympica Fossae
. Such streaks are common on Mars. They occur on steep slopes of craters, troughs, and valleys. The streaks are dark at first. They get lighter with age. Sometimes they start in a tiny spot, then spread out and go for hundreds of meters. They have been seen to travel around obstacles, like boulders. It is believed that they are avalanches of bright dust that expose a darker underlying layer. However, several ideas have been advanced to explain them. Some involve water or even the growth of organisms. The streaks appear in areas covered with dust. Much of the Martian surface is covered with dust. Fine dust settles out of the atmosphere covering everything. We know a lot about this dust because the solar panels of the Mars Rovers get covered with dust, thus reducing the electrical energy. The power of the Rovers has been restored many times by the wind, in the form of dust devils
, cleaning the panels and boosting the power. Dust storms are frequent, especially when the spring season begins in the southern hemisphere. At that time, Mars is 40% closer to the sun. The orbit of Mars is much more elliptical then the Earth's. That is the difference between the farthest point from the sun and the closest point to the sun is very great for Mars, but only a slight amount for the Earth. Also, every few years, the entire planet is engulfed in global dust storms. When NASA's Mariner 9
craft arrived there, nothing could be seen through the dust storm. Other global dust storms have also been observed, since that time.
Quadrangle (geography)
In geology or geography, the word "quadrangle" usually refers to a United States Geological Survey 7.5-minute quadrangle map, which are usually named after a local physiographic feature. The shorthand "quad" is also used, especially with the name of the map; for example, "the Ranger Creek, Texas...
is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
(USGS) Astrogeology Research Program
Astrogeology Research Program
The USGS Astrogeology Science Center has a rich history of participation in space exploration efforts and planetary mapping, starting in 1963 when the Flagstaff Science Center was established by Gene Shoemaker to provide lunar geologic mapping and assist in training astronauts destined for the...
. The Tharsis quadrangle is also referred to as MC-9 (Mars Chart-9).
The quadrangle covers the area from 90° to 135° west longitude and 0° to 30° north latitude on Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
and contains most of the Tharsis Rise
Tharsis
The Tharsis region on Mars is a vast volcanic plateau centered near the equator in Mars’ western hemisphere. The region is home to the largest volcanoes in the Solar System, including the three enormous shield volcanoes Arsia Mons, Pavonis Mons, and Ascraeus Mons, which are collectively known as...
. The plateau is about as high as Earth's Mount Everest and about as big in area as all of Europe. Tharsis contains a group of large volcanoes. Olympus Mons
Olympus Mons
Olympus Mons is a large volcanic mountain on the planet Mars. At a height of almost , it is one of the tallest mountains in the Solar System, three times as tall as Mount Everest and more than twice the height of Mauna Kea the tallest mountain on Earth. Olympus Mons is the youngest of the large...
is the tallest.
Volcanoes
Tharsis is a land of great volcanoes. Olympus MonsOlympus Mons
Olympus Mons is a large volcanic mountain on the planet Mars. At a height of almost , it is one of the tallest mountains in the Solar System, three times as tall as Mount Everest and more than twice the height of Mauna Kea the tallest mountain on Earth. Olympus Mons is the youngest of the large...
is the tallest known volcano in the Solar System; it is 100 times larger than any volcano on Earth. Ascraeus Mons
Ascraeus Mons
Ascraeus Mons is a large shield volcano located in the Tharsis region of the planet Mars. It is the northernmost and tallest of three shield volcanoes collectively known as the Tharsis Montes. The volcano's location corresponds to the classical albedo feature Ascraeus Lacus.Ascraeus Mons was...
and Pavonis Mons
Pavonis Mons
Pavonis Mons is a large shield volcano located in the Tharsis region of the planet Mars. It is the middle member of a chain of three volcanic mountains that straddle the Martian equator between longitudes 235°E and 259°E. The volcano was discovered by the Mariner 9 spacecraft in 1971 and was...
are at least 200 miles across and are over six miles above the plateau
Plateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...
that they sit on—and, the plateau is three to four miles above the zero altitude of Mars. Pavonis Mons, the middle in a line of three volcanoes, sits at just about dead center on the equator. Mons is a term used for a large raised feature. Tholus is about the same, but smaller. A patera is flatter and like a volcano with a super large opening. Actually, a patera is formed when the top of a volcano collapses because its magma chamber is empty. Crater Lake
Crater Lake
Crater Lake is a caldera lake located in the south-central region of the U.S. state of Oregon. It is the main feature of Crater Lake National Park and famous for its deep blue color and water clarity. The lake partly fills a nearly deep caldera that was formed around 7,700 years agoby the...
Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
was formed that way. Several volcanoes form a straight line in the Tharsis Uplift. Two major ones are in the Tharsus quadrangle: Ascraeus Mons and Pavonis Mons. It has been proposed that these are the result of plate motion which on Earth makes volcanic arc islands.
Tharsis Changed the Climate
Some scientists maintain that the great mass of Tharsis has had great influence on the climate of Mars. Volcanoes give off great amounts of gas when they erupt. The gases are usually water vapor and carbon dioxideCarbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
. Estimates put the amount of gas released to the atmosphere as enough to make the atmosphere thicker than the Earth's. In addition the water vapor from the volcanoes could have made enough water to place all of Mars under 120 meters of water. Of course, we all know that carbon dioxide is a greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
. It raises the temperature of a planet by trapping heat in the form of infrared radiation. So the eruption of lava on Tharsis could have made Mars Earth-like in the past. Mars may have once had a much thicker and warmer atmosphere. Oceans and/or lakes may have been present.
Fossa
The Tharsis quadrangle is also home to large troughs (long narrow depressions) called fossae in the geographical language used for Mars. Fossae in this area are Ulysses FossaeUlysses Fossae
Ulysses Fossae is a trough in the Tharsis quadrangle of Mars at 10.2° north latitude and 123.4° west longitude. It was named after an albedo feature name....
, Olympica Fossae
Olympica Fossae
Olympica Fossae is a trough in the Tharsis quadrangle of Mars at25° north latitude and 114.1° west longitude. It is about 420 km long and was named after an albedo feature at 17N, 134W...
, Ceraunius Fossae
Ceraunius Fossae
Ceraunius Fossae is an area of intensely fractured terrain in the northern Tharsis region of Mars. It lies directly south of the large volcano Alba Mons and consists of ancient highland crust that has been deformed by numerous parallel faults and tension cracks...
, and Tractus Fossae
Tractus Fossae
Tractus Fossae is a trough in the Tharsis quadrangle of Mars, located at 26° north latitude and 101.4° west longitude. It is long and is named after a classical albedo feature name. The name "Fossae" is used to indicate large troughs when using geographical terminology related to Mars...
. These troughs form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Studies have shown that the volcanoes of Tharsis caused most of the major fossae on Mars. The stress that caused the fossae and other tectonic features is centered in Noctis Labyrinthus
Noctis Labyrinthus
Noctis Labyrinthus, "the labyrinth of the night", is a region of Mars between the Valles Marineris and the Tharsis upland. It is located in the Phoenicis Lacus quadrangle. The region is notable for its maze-like system of deep, steep-walled valleys...
, at 4 S and 253 E. But the center has moved somewhat over time. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes. A trough often has two breaks with a middle section moving down, leaving steep cliffs along the sides; such a trough is called a graben
Graben
In geology, a graben is a depressed block of land bordered by parallel faults. Graben is German for ditch. Graben is used for both the singular and plural....
. Studies have found that on Mars a fault may be as deep as 5 km, that is the break in the rock goes down to 5 km. Moreover, the crack or fault sometimes widens or dialates. This widening causes a void to form with a relatively high volume. When material slides into the void, a pit crater or a pit crater chain forms. Pit craters do not have rims or ejecta around them, like impact craters do. On Mars, individual pit craters can join to form chains or even to form troughs that are sometimes scalloped. Other ideas have been suggested for the formation of fossae and pit craters. There is evidence that they are associated with dikes of magma. Magma might move along, under the surface, breaking the rock and, more importantly, melting ice. The resulting action would cause a crack to form at the surface. Pit craters are not common on Earth. Sinkholes, where the ground falls into a hole (sometimes in the middle of a town) resemble pit craters on Mars. However, on the Earth these holes are caused by limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
being dissolved thereby causing a void.
Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because they may be reservoirs of water.
Glaciers
Some scientists see evidence that glaciers exist on many of the volcanoes in Tharsis, including Olympus Mons, Ascraeus Mons, and Pavonis Mons. Ceraunius Tholus may have even had its glaciers melt to form some temporary lakes in the past.Dark slope streaks
Some pictures below show dark streaks: on the slopes on large blocks just to the left of Tharsis TholusTharsis Tholus
Tharsis Tholus is an intermediate-sized shield volcano located in the eastern Tharsis region of the planet Mars. The volcano was discovered by the Mariner 9 spacecraft in 1972 and originally given the informal name Volcano 7. In 1973, the International Astronomical Union officially designated...
, on Ceraunius Fossae
Ceraunius Fossae
Ceraunius Fossae is an area of intensely fractured terrain in the northern Tharsis region of Mars. It lies directly south of the large volcano Alba Mons and consists of ancient highland crust that has been deformed by numerous parallel faults and tension cracks...
, and on Olympica Fossae
Olympica Fossae
Olympica Fossae is a trough in the Tharsis quadrangle of Mars at25° north latitude and 114.1° west longitude. It is about 420 km long and was named after an albedo feature at 17N, 134W...
. Such streaks are common on Mars. They occur on steep slopes of craters, troughs, and valleys. The streaks are dark at first. They get lighter with age. Sometimes they start in a tiny spot, then spread out and go for hundreds of meters. They have been seen to travel around obstacles, like boulders. It is believed that they are avalanches of bright dust that expose a darker underlying layer. However, several ideas have been advanced to explain them. Some involve water or even the growth of organisms. The streaks appear in areas covered with dust. Much of the Martian surface is covered with dust. Fine dust settles out of the atmosphere covering everything. We know a lot about this dust because the solar panels of the Mars Rovers get covered with dust, thus reducing the electrical energy. The power of the Rovers has been restored many times by the wind, in the form of dust devils
Dust Devils
Dust Devils is an independently published role-playing game set in the Old West, written by Matt Snyder. It was voted the 2002 Indie RPG of the Year; it also won the Best Synergy of Game and Rules category, as well as placing in the Best Production and Most Innovative Game categories.The game uses...
, cleaning the panels and boosting the power. Dust storms are frequent, especially when the spring season begins in the southern hemisphere. At that time, Mars is 40% closer to the sun. The orbit of Mars is much more elliptical then the Earth's. That is the difference between the farthest point from the sun and the closest point to the sun is very great for Mars, but only a slight amount for the Earth. Also, every few years, the entire planet is engulfed in global dust storms. When NASA's Mariner 9
Mariner 9
Mariner 9 was a NASA space orbiter that helped in the exploration of Mars and was part of the Mariner program. Mariner 9 was launched toward Mars on May 30, 1971 from Cape Canaveral Air Force Station and reached the planet on November 13 of the same year, becoming the first spacecraft to orbit...
craft arrived there, nothing could be seen through the dust storm. Other global dust storms have also been observed, since that time.
See also
- Climate of MarsClimate of MarsThe climate of Mars has been an issue of scientific curiosity for centuries, not least because Mars is the only terrestrial planet whose surface can be directly observed in detail from the Earth....
- Water on MarsWater on MarsWater on Mars is a psychedelic rock and electronic music group from Quebec City, Québec, Canada. The music trio is led by Philippe Navarro, guitarist, vocalist, arranger, producer, principal lyricist, and music composer....
- Geology of MarsGeology of MarsThe geology of Mars is the scientific study of the surface, crust, and interior of the planet Mars. It emphasizes the composition, structure, history, and physical processes that shape the planet. It is fully analogous to the field of terrestrial geology. In planetary science, the term geology is...
- GlacierGlacierA glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
- Fossa (geology)Fossa (geology)Fossa is a term used in planetary geology to describe a long, narrow depression on the surface of an extraterrestrial body, such as a planet or moon...
- Dark slope streaks
- VolcanoVolcano2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
- TholusTholusIn planetary geology, tholus is the term used to describe a small domical mountain or hill. The word is from the Greek θόλος, which means a circular building with a conical or vaulted roof. The Romans transliterated the word into the Latin tholus, which means cupola or dome...
External links
- http://www.space.com/scienceastronomy/solarsystem/mars_tharsis_011009-1.html - for Mars animation of how Tharsis evolved.