Difference between revisions of "Ismenius Lacus quadrangle"
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ESP 046444 2225flows.jpg|Mantle and flow, as seen by HiRISE under HiWish program A part of the image showing the mantle is enlarged in the next image. | ESP 046444 2225flows.jpg|Mantle and flow, as seen by HiRISE under HiWish program A part of the image showing the mantle is enlarged in the next image. | ||
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File:ESP 057480 2205pyramid.jpg|Mantle layers, as seen by HiRISE under HiWish program Mantle layers seem to be forming a group of dipping layers. | File:ESP 057480 2205pyramid.jpg|Mantle layers, as seen by HiRISE under HiWish program Mantle layers seem to be forming a group of dipping layers. | ||
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==See also== | ==See also== | ||
Revision as of 11:58, 7 March 2020
| MC-05 | Ismenius Lacus | 30–65° N | 0–60° E | Quadrangles | Atlas |
Elevations
This quadrangle has some of the most mysterious-looking landscapes on the planet. It truly looks like another world here. The Ismenius Lacus quadrangle contains regions called Deuteronilus Mensae and Protonilus Mensae, two places that are of special interest to scientists. They contain abundant evidence of present and past glacial activity. They also have a landscape unique to Mars, called Fretted terrain. The largest crater in the area is Lyot Crater, which contains channels probably carved by liquid water.[1]
The Ismenius Lacus quadrangle is located in the northern hemisphere and covers 30° to 65° north latitude and 300° to 360° west longitude (60° to 0° east longitude). The southern and northern borders of the Ismenius Lacus quadrangle are approximately 3065 km (1,905 mi) and 1500 km wide (930 mi) respectively. The north-to-south distance is about 2050 km (1,270 mi) (a bit less than the length of Greenland).[2] The Ismenius Lacus quadrangle contains parts of regions named Acidalia Planitia, Arabia Terra, Vastitas Borealis, and Terra Sabaea.[3]
Contents
Origin of names
Ismenius Lacus is the name of a classical albedo feature located at 40° N and 30° E on Mars. The term is Latin for Ismenian Lake, and refers to the Ismenian Spring near Thebes in Greece where Cadmus slew the guardian dragon. Cadmus was the legendary founder of Thebes, and had come to the spring to fetch water. The name was approved by the International Astronomical Union (IAU) in 1958.[4] All names suggested for astronomical features have to eventually approved by the International Astronomical Union (IAU). Some important areas in this quadrangle derive from the names of canals that some early astronomers saw in this broad area. One such large canal they called Nilus. Since 1881–1882 it was split into other canals, some were called Nilosyrtis, Protonilus (first Nile),and Deuteronilus (second Nile).[5]
Channels (Rivers)
Many features were probably rivers with water flowing in them billions of years ago. Pictures below show many channels and parts of channels.
The channel shown below goes quite a long distance and has branches. It ends in a depression that may have been a lake at one time. The first picture is a wide angle, taken with CTX; while the second is a close up taken with HiRISE.[6]
Channels in Arabia, as seen by CTX This channel winds along for a good distance and has branches. It ends in a depression that may have been a lake at one time.
Channel in Arabia, as seen by HiRISE under HiWish program. This is an enlargement of the previous image that was taken with CTX to give a wide view.
Some places (like below) display a smaller channel within a larger, wider channel or valley. When this occurs it means water went through the region at least two times in the past. This implies that water was not here once for just a short period of time.
Channel within larger channel The existence of the smaller channel suggests water went through the region at least two times in the past.
Close-up of channel within larger channel The existence of the smaller channel suggests water went through the region at least two times in the past. The black box represents the size of a football field. Some parts of the surface would be difficult to walk on with the many small hills and depressions.
Channel system that travels through part of a crater
Channel that cut through a crater rim
Channel system that travels through part of a crater Note: this is an enlargement of a previous image.
Channel that travels through part of a crater The arrow shows a crater that was eroded by the channel. Note: this is an enlargement of a previous image.
Channels
Meander in a channel Meanders are commonly formed in old river systems when the water is moving slowly.
Wide view of channels
Close view of channel
Channel that has cut through a crater rim
Wide view of channels, as seen by HiRISE under HiWish program
Wide view of channels
Channel
Wide view of channels
Channel with hanging valley
Wide view of channels
Wide view of channels, as seen by HiRISE under HiWish program
Channel
Channels
Channels, as seen by HiRISE under HiWish program
Channels, Some parts of the image show mantle and others show no mantle covering the surface.
Possible inverted channel Here after a stream bed got filled with erosion resistant materials, the surrounding, softer landscape eroded away.
Lyot Crater
The vast northern plains of Mars are generally flat and smooth with few craters. However, a few large craters do stand out. The giant impact crater, Lyot, is easy to see in the northern part of Ismenius Lacus. There are only a very few craters along the far northern latitudes.[7] Lyot Crater is the deepest point in Mars's northern hemisphere.[8] One image below of Lyot Crater Dunes shows a variety of interesting forms: dark dunes, light-toned deposits, and Dust Devil Tracks. Dust devils, which resemble miniature tornados, create tracks by removing a thin, but bright deposit of dust to reveal the darker underlying surface. It does not take too much fine dust to cover those tracks--experiments in Earth laboratories demonstrate that only a few 10's of microns of dust will do the trick. Note on units: a micron is an older name for micrometre or micrometer. The width of a single human hair ranges from approximately 20 to 200 microns (μm); hence, the dust that can cover dust devil tracks may only be the thickness of a human hair.[9] Light-toned materials are an important find because they are widely believed to contain minerals formed in water. Research, published in June 2010, described evidence for liquid water in Lyot crater in the past.
Many channels have been found near Lyot Crater. Research, published in 2017, concluded that the channels were made from water released when the hot ejecta landed on a layer of ice that was 20 to 300 meters thick. Calculations suggest that the ejecta would have had a temperature of at least 250 degrees Fahrenheit. The valleys seem to start from beneath the ejecta near the outer edge of the ejecta. The existence of these channels is unusual because although Mars used to have water in rivers, lakes, and an ocean, these features have been dated to times after we had thought that many of these features had disappeared.[10] [11][12]
Wide view of channels in Lyot Crater, as seen by HiRISE unser HiWish program
Close view of channels in Lyot Crater
Close view of channels in Lyot Crater, as seen by HiRISE under HiWish program
Lyot Crater Dunes, as seen by HiRISE. Click on image to see light-toned deposits and dust devil tracks.
Channel
Other craters
Impact craters generally have a rim with ejecta around them; in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter), they usually have a central peak.[13] The peak is caused by a rebound of the crater floor following the impact.[14] Sometimes craters will display layers in their walls. Since the collision that produces a crater is like a powerful explosion, rocks from deep underground are tossed unto the surface. Hence, craters are useful for showing us what lies deep under the surface.
Fresh crater, as seen by HiRISE under HiWish program This is a young crater because one can easily see the rim and ejecta. They have not yet been eroded.
West side of Sinton Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter) A central peak is visible--it occurs in larger craters and is caused by a rebound from the force of the impact.
Crater with a bench A crater with a bench may be formed from settling of the crater wall or it may be due to impact into something with vastly different types of layers.
Possible expanded secondary craters, as seen by HiRISE under HiWish program These craters may have become much wider, as ice left the ground around the rims.[15] [16]
Impact crater that may have formed in ice-rich ground, as seen by HiRISE under HiWish program
Impact crater that may have formed in ice-rich ground Note that the ejecta seems lower than the surroundings. The hot ejecta may have caused some of the ice to go away; thus lowering the level of the ejecta.
Pedestal crater The crater's ejecta protected the underlying ground from eroding.
Pedestal crater Mesa on the crater floor formed after the crater.
Valleys on the Ejecta Blanket from Cerulli Crater, as seen by HiRISE.
Cerulli Crater, as seen by HiRISE It looks like a delta was formed as channels bought in debris and dumped then in a lake that was in the crater.
Northeast rim of Quenisset Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter). Note: this is an enlargement of the previous image of Quenisset Crater. Arrows indicate old glaciers.
Group of layers in crater
Fretted terrain
The Ismenius Lacus quadrangle contains several interesting features such as fretted terrain, parts of which are found in Deuteronilus Mensae and Protonilus Mensae. Fretted terrain contains smooth, flat lowlands along with steep cliffs. The scarps or cliffs are usually 1 to 2 km high. Channels in the area have wide, flat floors and steep walls. Many buttes and mesas are present. In fretted terrain the land seems to transition from narrow straight valleys to isolated mesas.[17] Most of the mesas are surrounded by forms that have been called a variety of names: circum-mesa aprons, debris aprons, rock glaciers, and lobate debris apron (LDA)s. The flat floors here often display many lines or lineations that scientists call lineated valley fill (LVF). These are cause by glacier-like flow. [18] At first they appeared to resemble rock glaciers on Earth. But scientists could not be sure. Even after the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took a variety of pictures of fretted terrain, experts could not tell for sure if material was moving or flowing as it would in an ice-rich deposit (glacier). Eventually, proof of their true nature was discovered by radar studies with the Mars Reconnaissance Orbiter showed that they contain pure water ice covered with a thin layer of rocks that insulated the ice.[19] [20]
Fretted terrain of Ismenius Lacus showing flat floored valleys and cliffs. Photo taken with Mars Orbiter Camera (MOC)on the Mars Global Surveyor, under the MOC Public Targeting Program. The white rectangle indicates the position of a high resolution image.
Enlargement of the photo on the left showing cliff. Photo taken with high-resolution camera of Mars Global Surveyor (MGS), under the MOC Public Targeting Program.
Wide view of mesa with CTX showing cliff face and location of lobate debris apron (LDA). Location is Ismenius Lacus quadrangle.
Enlargement of previous CTX image of mesa. This image shows the cliff face and detail in the LDA. Image taken with HiRISE under HiWish program. Location is Ismenius Lacus quadrangle.
Wide CTX view showing mesa and buttes with lobate debris aprons and lineated valley fill around them. Location is Ismenius Lacus quadrangle.
Close-up of lineated valley fill (LVF), as seen by HiRISE under HiWish program. Note: this is an enlargement of the previous CTX image.
Example of frettered terrain, as seen by HiRISE under HiWish program Fretted terrain contains many wide, flat-floored valleys.
Glaciers
Glaciers formed much of the observable surface in large areas of Mars. Much of the area in high latitudes, especially the Ismenius Lacus quadrangle, is believed to still contain enormous amounts of water ice.[21] [22] [23] In March 2010, scientists released the results of a radar study of an area called Deuteronilus Mensae that found widespread evidence of ice lying beneath a few meters of rock debris.[24] The ice was probably deposited as snowfall during an earlier climate when the poles were tilted more.[25] It would be difficult to take a hike on the fretted terrain where glaciers are common because the surface is folded, pitted, and often covered with linear striations.[26] The striations show the direction of movement. Much of this rough texture is due to sublimation of buried ice. The ice goes directly into a gas (this process is called sublimation) and leaves behind an empty space. Overlying material then collapses into the void.[27] Glaciers are not pure ice; they contain dirt and rocks. At times, they will dump their load of materials into ridges. Such ridges are called moraines.
The arrow in the left picture points to a possibly valley carved by a glacier. The image on the right shows the valley greatly enlarged in a Mars Global Surveyor image.
Glacier moving out of valley, as seen by HiRISE under HiWish program
Romer Lake's Elephant Foot Glacier in the Earth's Arctic, as seen by Landsat 8. This picture shows several glaciers that have the same shape as many features on Mars that are believed to also be glaciers.
Glacier coming out of valley Location is rim of Moreux Crater.
Flow, as seen by HiRISE under HiWish program
Flow
Glaciers moving form valleys in a mesa
Two glaciers interacting The one on the left is more recent and is flowing on top of the other one.
Glacier interacting with an obstacle
Glacier flowing out of valley
Ridge that is probably from an old glacier
Lineated valley fill, as seen by HiRISE under HiWish program.
Close view of Lineated valley fill
Close, color view of Lineated valley fill
Lineated valley fill in valley
Lineated valley fill in valley Linear valley flow is ice covered by debris.
Close, color view of lineated valley fill
Probable glacier Radar studies have found that it is made up of almost completely pure ice. It appears to be moving from the high ground (a mesa) on the right.
Mesa in Ismenius Lacus quadrangle, as seen by CTX. Mesa has several glaciers eroding it. One of the glaciers is seen in greater detail in the next two images from HiRISE.
Glacier as seen by HiRISE under the HiWish program. Area in rectangle is enlarged in the next photo. Zone of accumulation of snow at the top. Glacier is moving down valley, then spreading out on plain. Evidence for flow comes from the many lines on surface. Location is in Protonilus Mensae.
Enlargement of area in rectangle of the previous image. On Earth the ridge would be called the terminal moraine of an alpine glacier.
Remains of a glacier after ice has disappeared
Lobate debris aprons (LDAs) around a mesa, as seen by CTX Mesa and LDAs are labeled so one can see their relationship. Radar studies have determined that LDAs contain ice; therefore these can be important for future colonists of Mars.
Wide CTX view of mesa showing lobate debris apron (LDA) and lineated valley fill. Both are believed to be debris-covered glaciers.
Close-up of lobate debris apron from the previous CTX image of a mesa. Image shows open-cell brain terrain and closed-cell brain terrain, which is more common. Open-cell brain terrain is thought to hold a core of ice.
Lobate debris apron around mesa
Close view of lobate debris apron around mesa Brain terrain is visible.
Glaciers moving in two different valleys
Wide view of flow moving down valley
Close view of part of glacier Box shows size of football field.
Flow and mantle,
Wide view of tongue-shaped glacier and lineated valley fill
Tongue-shaped glacier Note: this is an enlargement of the previous image
Close view of tongue-shaped glacier Surface is broken up into cubes.
Latitude dependent mantle
Much of the Martian surface is covered with a thick ice-rich, mantle layer that has fallen from the sky a number of times in the past.[28] [29] [30]
Close view of mantle Arrows show craters along edge which highlight the thickness of mantle.
Close view that displays the thickness of mantle.
Mantle and flow, as seen by HiRISE under HiWish program A part of the image showing the mantle is enlarged in the next image.
Mantle, as seen by HiRISE under HiWish program
Close view of mantle, as seen by HiRISE under HiWish program
Close view of mantle, as seen by HiRISE under HiWish program
Color view of mantle, as seen by HiRISE under HiWish program Some parts of the image are covered with mantle; other parts are not.
Mantle layers, as seen by HiRISE under HiWish program
Mantle layers, as seen by HiRISE under HiWish program Mantle layers seem to be forming a group of dipping layers.
See also
- Dark slope streaks
- Geography of Mars
- High Resolution Imaging Science Experiment (HiRISE)
- HiWish program
- How are features on Mars Named?
- Glaciers on Mars
- Layers on Mars
- Mars Global Surveyor
- Rivers on Mars
References
- ↑ Carter | first1 = J. | last2 = Poulet | first2 = F. | last3 = Bibring | first3 = J.-P. | last4 = Murchie | first4 = S. | year = 2010 | title = Detection of Hydrated Silicates in Crustal Outcrops in the Northern Plains of Mars | url = | journal = Science | volume = 328 | issue = 5986| pages = 1682–1686 |
- ↑ Distances calculated using NASA World Wind measuring tool. http://worldwind.arc.nasa.gov/.
- ↑ http://planetarynames.wr.usgs.gov/SearchResults?target=MARS&featureType=Terra,%20terrae
- ↑ USGS Gazetteer of Planetary Nomenclature. Mars. http://planetarynames.wr.usgs.gov/.
- ↑ Blunck, J. 1982. Mars and its Satellites. Exposition Press. Smithtown, N.Y.
- ↑ http://www.uahirise.org/ESP_039997_2170
- ↑ U.S. department of the Interior U.S. Geological Survey, Topographic Map of the Eastern Region of Mars M 15M 0/270 2AT, 1991
- ↑ http://space.com/scienceastronomy/090514--mars-rivers.html
- ↑ https://en.wikipedia.org/wiki/Micrometre
- ↑ doi=10.1002/2017GL073821 | volume=44 | issue=11 | title=Extensive Amazonian-aged fluvial channels on Mars: Evaluating the role of Lyot crater in their formation | journal=Geophysical Research Letters | pages=5336–5344 | last1 = Weiss | first1 = David K.|
- ↑ Weiss, D., et al. 2017. Extensive Amazonian-aged fluvial channels on Mars: Evaluating the role of Lyot crater in their formation. Geophysical Research Letters: 44, doi:10.1002/2017GL073821.
- ↑ http://spaceref.com/mars/hot-rocks-led-to-relatively-recent-water-carved-valleys-on-mars.html
- ↑ http://www.lpi.usra.edu/publications/slidesets/stones/
- ↑ Template:Cite book
- ↑ http://www.uahirise.org/epo/nuggets/expanded-secondary.pdf
- ↑ Viola, D., et al. 2014. EXPANDED CRATERS IN ARCADIA PLANITIA: EVIDENCE FOR >20 MYR OLD SUBSURFACE ICE. Eighth International Conference on Mars (2014). 1022pdf.
- ↑ Sharp, R. 1973. Mars Fretted and chaotic terrains. J. Geophys. Res.: 78. 4073–4083
- ↑ http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1053.pdf
- ↑ Plaut, J. et al. 2008. Radar Evidence for Ice in Lobate Debris Aprons in the Mid-Northern Latitudes of Mars. Lunar and Planetary Science XXXIX. 2290.pdf
- ↑ Plaut | first1 = J. | last2 = Safaeinili | first2 = A. | last3 = Holt | first3 = J. | last4 = Phillips | first4 = R. | last5 = Head | first5 = J. | last6 = Seu | first6 = R. | last7 = Putzig | first7 = N. | last8 = Frigeri | first8 = A. | year = 2009 | title = Radar evidence for ice in lobate debris aprons in the midnorthern latitudes of Mars | url = https://semanticscholar.org/paper/f6b94761e6a276ce6894374ae9bea88fdc3e5e19%7C journal = Geophys. Res. Lett. | volume = 36| issue = 2| pages = n/a |
- ↑ Hugh H. Kieffer (1992). Mars. University of Arizona Press. ISBN 978-0-8165-1257-7
- ↑ Plaut, J. et al. 2008. Radar Evidence for Ice in Lobate Debris Aprons in the Mid-Northern Latitudes of Mars. Lunar and Planetary Science XXXIX. 2290.pdf
- ↑ http://www.esa.int/SPECIALS/Mars_Express/SEMBS5V681F_0.html
- ↑ http://news.discovery.com/space/mars-ice-sheet-climate.html
- ↑ Madeleine, J. et al. 2007. Exploring the northern mid-latitude glaciation with a general circulation model. In: Seventh International Conference on Mars. Abstract 3096.
- ↑ http://www.uahirise.org/ESP_018857_2225
- ↑ http://hirise.lpl.arizona.edu/PSP_009719_2230
- ↑ Hecht | first1 = M | year = 2002 | title = Metastability of water on Mars | url = | journal = Icarus | volume = 156 | issue = 2| pages = 373–386 | doi=10.1006/icar.2001.6794 |
- ↑ Mustard | first1 = J. |display-authors=etal | year = 2001 | title = Evidence for recent climate change on Mars from the identification of youthful near-surface ground ice | url = | journal = Nature | volume = 412 | issue = 6845| pages = 411–414 |
- ↑ Pollack | first1 = J. | last2 = Colburn | first2 = D. | last3 = Flaser | first3 = F. | last4 = Kahn | first4 = R. | last5 = Carson | first5 = C. | last6 = Pidek | first6 = D. | year = 1979 | title = Properties and effects of dust suspended in the martian atmosphere | url = | journal = J. Geophys. Res. | volume = 84 | issue = | pages = 2929–2945 | doi=10.1029/jb084ib06p02929 |
