Abalos Undae (Latin for "Abalos Waves") is adune field onMars in the periphery ofPlanum Boreum, the Martian North pole. It is one of theofficially named northern circumpolar dune fields, along withOlympia,Hyperboreae, andSiton Undae, and also one of the densest of the region.[1][2] Its northernmost boundary is located in the southwest channel that separates theAbalos Colles formation from the main polar ice cap, and from there the dune field extends southwest all the way to the lowlands ofVastitas Borealis.[2][3][4]
It is theorised that the dunes of the Abalos field may have resulted from erosion ofRupes Tenuis (Latin:Thin Cliff), the polarscarp.[2][5] Its name was approved by theInternational Astronomical Union in 1988.[1] 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 classicalalbedo feature with coordinates 72°N, 70°W and has a diameter of 442.74 km.[1]
Abalos Undae is adune field onMars, 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 nearbyclassical albedo features.[2] 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.[2][4] The dunes of the Abalos field may have formed from erosion ofRupes Tenuis, the polarscarp.[2][5] Abalos Undae has its northernmost boundary in the neighbourhood ofAbalos Mensa and continues in a southwestward direction after it emerges from the western end of a narrow channel separating Rupes Tenuis from Abalos Mensa.[3]
Enhanced colour images obtained by theHigh Resolution Imaging Science Experiment (HiRISE) camera on board theMars Reconnaissance Orbiter highlight the areas of the dunes where different materials are present.[2] The blue areas indicate the presence of dunes ofbasaltic origin, while the light-colour areas are probably dust. The pictures are of sufficient resolution to show ripples on the dune surface.[2] The ripples are generated by winds, as are the dunes.[2] The dunes are considered stationary as a unit, with only small ripple movements present.[2]
Similarly to the rest of the dune fields around the periphery of Planum Borealis, the Abalos dune field is considered to consist oflag deposits resulting from theablation of the sediment found inbasal units.[4] 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.[6][7]
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.[6] Abalos Undae, along with Hyperboreae and Siton Undae, is a sand tributary to mostly medium-density sand fields located east ofOlympia Undae and extending to theprime meridian of Mars.[6] 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 highestpixel density indicating the presence ofgypsum.[7] The gypsum of Abalos Undae may be eroding due to scouring action by substrates of bedrock involved in plains formation.[6]
