Mare Tyrrhenum quadrangle
Encyclopedia
The Mare Tyrrhenum quadrangle
is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey
(USGS) Astrogeology Research Program
. The Mare Tyrrhenum quadrangle is also referred to as MC-22 (Mars Chart-22).
The Mare Tyrrhenum quadrangle covers the area from 225° to 270° west longitude and 0° to 30° south latitude on Mars
. Schiaparelli
named the area after Earth's Tyrrhenian Sea
, which lies between Italy and Sicily. The region was subsequently renamed to Mare Tyrrhena after spacecraft photos revealed that it is an old, cratered plain rather than a sea. It contains the large volcano Tyrrhena Patera
, one of the oldest, and perhaps the most complex volcanoes on Mars. Mare Tyrrhenum's largest crater is Herschel
. Licus Vallis
and the Ausonia Montes
are other major features in the region.
. Lake George
, in northern New York State, is a lake that sits in 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 dilates. 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. Tyrrhnena Patera has some beautiful fossae and pit craters associated with it. These features are easily visible in the image below of Tyrrhena Patera
, as seen by HiRISE
.
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.
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 Mare Tyrrhenum quadrangle is also referred to as MC-22 (Mars Chart-22).
The Mare Tyrrhenum quadrangle covers the area from 225° to 270° west longitude and 0° to 30° south 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...
. Schiaparelli
Schiaparelli
Schiaparelli is an Italian surname and may refer to:*Elsa Schiaparelli , Italian clothing designer*Ernesto Schiaparelli , Italian Egyptologist...
named the area after Earth's Tyrrhenian Sea
Tyrrhenian Sea
The Tyrrhenian Sea is part of the Mediterranean Sea off the western coast of Italy.-Geography:The sea is bounded by Corsica and Sardinia , Tuscany, Lazio, Campania, Basilicata and Calabria and Sicily ....
, which lies between Italy and Sicily. The region was subsequently renamed to Mare Tyrrhena after spacecraft photos revealed that it is an old, cratered plain rather than a sea. It contains the large volcano Tyrrhena Patera
Tyrrhena Patera
Tyrrhena Patera is the central depression of a large volcano in the Mare Tyrrhenum quadrangle of Mars, located at 21.36° south latitude and 253.47° west longitude. It was named after a classical albedo feature name. Pit chains are found at the summit of Tyrrhena Patera. They are formed by...
, one of the oldest, and perhaps the most complex volcanoes on Mars. Mare Tyrrhenum's largest crater is Herschel
Herschel (crater)
There are several impact craters named Herschel in the solar system, although the best known is the huge crater on Saturn's moon Mimas. Most are named after the eighteenth century astronomer William Herschel.*Herschel , on the Moon...
. Licus Vallis
Licus Vallis
Licus Vallis is an ancient river valley in the Mare Tyrrhenum quadrangle of Mars, located at 2.9° south latitude and 233.9° west longitude. It is 219.1 km long and was named after an ancient name for modern Lech River in Germany and Austria....
and the Ausonia Montes
Ausonia Montes
Ausonia Montes is a mountain in the Mare Tyrrhenum quadrangle of Mars, at 27.7° south latitude an 261.2° west longitude. It is across and was named after an albedo feature name....
are other major features in the region.
Fossa on Mars
Large troughs (long narrow depressions) are called fossae in the geographical language used for Mars. Troughs form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. 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 grabenGraben
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....
. Lake George
Lake George (New York)
Lake George, nicknamed the Queen of American Lakes, is a long, narrow oligotrophic lake draining northwards into Lake Champlain and the St. Lawrence River Drainage basin located at the southeast base of the Adirondack Mountains in northern New York, U.S.A.. It lies within the upper region of the...
, in northern New York State, is a lake that sits in 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 dilates. 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
Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...
. 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. Tyrrhnena Patera has some beautiful fossae and pit craters associated with it. These features are easily visible in the image below of Tyrrhena Patera
Tyrrhena Patera
Tyrrhena Patera is the central depression of a large volcano in the Mare Tyrrhenum quadrangle of Mars, located at 21.36° south latitude and 253.47° west longitude. It was named after a classical albedo feature name. Pit chains are found at the summit of Tyrrhena Patera. They are formed by...
, as seen by HiRISE
HiRISE
High Resolution Imaging Science Experiment is a camera on board the Mars Reconnaissance Orbiter. The 65 kg , $40 million instrument was built under the direction of the University of Arizona's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp....
.
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.