Abalos Undae (

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for "Abalos Waves") is a

dune field A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

in the periphery of

Planum Boreum Planum Boreum (Latin: "the northern plain") is the northern polar plain on Mars. It extends northward from roughly 80°N and is centered at . Surrounding the high polar plain is a flat and featureless lowland plain called Vastitas Borealis which ...

, the Martian North pole. It is one of the officially named northern circumpolar dune fields, along with Olympia, Hyperboreae, and Siton Undae, and also one of the densest of the region. Its northernmost boundary is located in the southwest channel that separates the

Abalos Colles Abalos Colles (Latin for "Abalos Hills") is a stratified fragment of the Rupes Tenuis basal unit of Planum Boreum, located south of the Rupes Tenuis scarp and west of the Escorial crater. It contains 16 mounds. Abalos Colles is one of the named f ...

formation from the main polar ice cap, and from there the dune field extends southwest all the way to the lowlands of

Vastitas Borealis (Latin 'northern waste') is the largest lowland region of Mars. It is in the northerly latitudes of the planet and encircles the northern polar region. Vastitas Borealis is often simply referred to as the northern plains, northern lowlands or ...

. It is theorised that the dunes of the Abalos field may have resulted from erosion of ''

Rupes Tenuis Rupes Tenuis ( la, thin cliff) is a Martian north polar scarp. It is named after one of the classical albedo features on Mars. Its name was officially approved by IAU in 1988. It extends from latitude 74.94°N to 82.2°N and from longitude 242 ...

'' ( la, Thin Cliff), the polar scarp. Its name was approved by the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

in 1988. It extends from latitude 74.94°N to 82.2°N and from longitude 261.4°E to 283.03°E (76.97°W – 98.6°W). Its origin is located at classical albedo feature with coordinates 72°N, 70°W and has a diameter of 442.74 km.

Location and formation characteristics

Distribution of dune fields in the Planum Boreum region

Abalos Undae is a

, in the periphery of Planum Boreum, the Martian north pole. It is a part of the northern circumpolar dune fields, along with Olympia, Hyperboreae, and Siton Undae, which are officially named after nearby

classical albedo features The classical albedo features of Mars are the light and dark features that can be seen on the planet Mars through an Earth-based telescope. Before the age of space probes, several astronomers created maps of Mars on which they gave names to the fe ...

. It is located in the southwest channel that separates the Abalos Colles formation remnant from the main ice cap, and continues all the way to the channel's southern boundary. The dunes of the Abalos field may have formed from erosion of ''Rupes Tenuis'', the polar scarp.NASA
quote: "Today's image location is slightly east of Monday's image. In this image the polar scarp (called Tenuis Rupes) bisects the image. Abalos Undae has its northernmost boundary in the neighbourhood of

Abalos Mensa Abalos Mensa is a wedge-shaped mound, or mensa and one of the named features in the vicinity of Planum Boreum, the Martian North pole. It is named after one of the classical albedo features on Mars. Its name was officially approved by IAU in 20 ...

and continues in a southwestward direction after it emerges from the western end of a narrow channel separating Rupes Tenuis from Abalos Mensa. Enhanced colour images obtained by the

High Resolution Imaging Science Experiment High Resolution Imaging Science Experiment is a camera on board the ''Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction o ...

(HiRISE) camera on board the

Mars Reconnaissance Orbiter ''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, an ...

highlight the areas of the dunes where different materials are present. The blue areas indicate the presence of dunes of

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...

ic origin, while the light-colour areas are probably dust. The pictures are of sufficient resolution to show ripples on the dune surface. The ripples are generated by winds, as are the dunes. The dunes are considered stationary as a unit, with only small ripple movements present. Similarly to the rest of the dune fields around the periphery of Planum Borealis, the Abalos dune field is considered to consist of

lag deposit A lag deposit is the deposition of material winnowed by physical action. Aeolian processes, fluvial processes, and tidal processes can remove the finer portion of a sedimentary deposit leaving the coarser material behind. Lag deposits are found i ...

s resulting from the

ablation Ablation ( la, ablatio – removal) is removal or destruction of something from an object by vaporization, chipping, erosive processes or by other means. Examples of ablative materials are described below, and include spacecraft material for a ...

of the sediment found in basal units. The Abalos dune field is considered one of the densest dune fields in the northern circumpolar region of Mars. Other fields of similar density in the region include the Olympia, Hyperboreae, and Siton Undae. The Abalos dune field consists of transverse dune linear sequences that, overall, form platforms of sand ranging from approximately 10 metres to 200 metres thickness. Abalos Undae, along with Hyperboreae and Siton Undae, is a sand tributary to mostly medium-density sand fields located east of Olympia Undae and extending to the

prime meridian A prime meridian is an arbitrary meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. Together, a prime meridian and its anti-meridian (the 180th meridian in a 360°-system) form a great ...

of Mars. Image analysis, performed using the method of spectral derivatives, indicates that Abalos Undae, and the rest of the densest dunes fields in the periphery of Planum Borealis, Olympia Undae and Hyperboreae Undae, show the highest pixel density indicating the presence of

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywal ...

. The gypsum of Abalos Undae may be eroding due to scouring action by substrates of bedrock involved in plains formation.

Images by HiRISE and THEMIS

File:PSP 009367 2620 RED Aeolian Source Layers Exposed in Northwestern Abalos Scopuli.jpg, Abalos Undae at Abalos Scopuli, the scarp of

File:PSP 010501 2615 MIRB Abalos Undae map-projected.jpg, Gypsum deposits in the dunes of Abalos Undae map-projected in IRB colour File:Dunes in Abalos Undae.jpeg, Dunes in Abalos Undae. The blue areas indicate the presence of dunes of basaltic origin, while the light-colour areas are probably dust. File:Sample of Abalos Undae Gypsum.jpeg, Gypsum deposits in the dunes of Abalos Undae File:Dunes in Abalos Undae, Mars.jpg, Dunes in Abalos Undae File:PSP 010501 2615 MRGB Abalos Undae Gypsum map projected.jpg, The dunes of Abalos Undae with gypsum deposits map-projected in RGB colour File:PSP 010501 2615 MIRB Abalos Undae with scale.jpg, The dunes of Abalos Undae with gypsum deposits map-projected in IRB colour with scale File:PSP 010501 2615 Abalos Undae Gypsum.jpg, The dunes of Abalos Undae with gypsum deposits map-projected in IRB colour File:ESP 035924 2620 MRGB North Polar Scarp in Abalos Undae with Basal Exposure and Dunes.jpg, North Polar Scarp in Abalos Undae with Basal Exposure and Dunes map-projected in RGB colour and distance scale File:ESP 035924 2620 RED North Polar Scarp in Abalos Undae with Basal Exposure and Dunes black and white.jpg, North Polar Scarp in Abalos Undae with Basal Exposure and Dunes in black and white File:ESP 034500 2620 RED North Polar Scarp in Abalos Undae with Basal Exposure and Dunes black and white with scale.jpg, North Polar Scarp in Abalos Undae with Basal Exposure and Dunes in black and white with scale File:ESP 034500 2620 RED North Polar Scarp in Abalos Undae with Basal Exposure and Dunes black and white.jpg, North Polar Scarp in Abalos Undae with Basal Exposure and Dunes in black and white File:Abalos Undae dunes and crater.png, Abalos Undae dunes and crater File:Polar cap scarp in Abalos Undae THEMIS IOTD 20160511.jpg , The edge of the dark dunes of Abalos Undae shown just below the polar scarp and cap File:ESP 035924 2620 North Polar Scarp in Abalos Undae with Basal Exposure and Dunes.jpg, Abalos Undae dunes with brightness adjusted

References

External links

HiRISE entry for North Polar Scarp in Abalos Undae with Basal Exposure and Dunes
{{Portal bar, Solar System Dunes on Mars Mare Boreum quadrangle

Location and formation characteristics

Images by HiRISE and THEMIS

See also

References

External links