Alcoves is the geographical and geological term for a steep-sided hollow in the side of an exposed rock face or cliff of a homogeneous rock type, that was water eroded. They are created through weathering, erosion, dry granular flow, and stress. Another factor in the formation of alcoves is winds between mid to late summer that steepen at the edge which leads to the failure and shaping of sand deposition in certain areas.[1]
Although alcoves are both found in the northern and southern hemisphere, more newly developed alcoves are in the northern hemisphere region. Around the North Pole, dune alcoves, dune furrows, and scarp avalanches can form.[2] The mechanism dune furrows are formed are through cryo jets and many form at alluvial fans. Furrows are channels and although mostly small they can vary in size and everytime they form in the spring season. Furrows do not have a long lifetime as they are often blown away by strong summer winds.
South Poleedit
In comparison, the South Pole differs in having higher elevation which can cause changes in alcove formation. These differences include the South Pole having older alcoves due to its denser deposition craters which are approximately 2 to 3 m thick which include particles of ice and minerals, and craters that contains carbon dioxide ice.[2] Both South Pole and North Pole alcoves are formed through stress cementing the sandstone particles together. So after erosion, at the area where the most rock has been excavated by weathering the pressure builds up and the sand particles become very stable and hold the arch above.[1]
Locations on Other Planetary Bodiesedit
Marsedit
Alcoves with Alluvial Fans on Surface of Mars
Annually in the North Pole region, alcove formation is most active during autumn and winter seasons and also form specific alcove-apron regions during springtime sublimation. This is when the alcoves start at the edge of dunes and deposit and end into an apron fan shape.[3] During summertime on Mars, strong winds will blow away smaller less stable alcoves which starts the cycle for new alcoves to form the following autumn and winter. It is estimated that alcove formation is responsible for a range of 2 to 20% of sand movement on Mars.[3]
Referencesedit
^ abBruthans, Jiri; Soukup, Jan; Vaculikova, Jana; Filippi, Michal; Schweigstillova, Jana; Mayo, Alan L.; Masin, David; Kletetschka, Gunther; Rihosek, Jaroslav (2014). "Sandstone landforms shaped by negative feedback between stress and erosion". Nature Geoscience. 7 (8): 597–601. Bibcode:2014NatGe...7..597B. doi:10.1038/ngeo2209. ISSN 1752-0908.
^ abPortyankina, Ganna; Aye, K. -Michael (2018), Soare, Richard J.; Conway, Susan J.; Clifford, Stephen M. (eds.), "Chapter 6 - CO2-Driven Geomorphological Processes: Landscape Evolution", Dynamic Mars, Elsevier, pp. 187–205, ISBN978-0-12-813018-6, retrieved 2023-03-18
^ abDiniega, Serina; Hansen, Candice J.; Allen, Amanda; Grigsby, Nathan; Li, Zheyu; Perez, Tyler; Chojnacki, Matthew (2017). "Dune-slope activity due to frost and wind throughout the north polar erg, Mars". Geological Society Special Publication. 467: 95–114. doi:10.1144/SP467.6. PMC5932633. PMID 29731538.
alcove, landform, alcoves, geographical, geological, term, steep, sided, hollow, side, exposed, rock, face, cliff, homogeneous, rock, type, that, water, eroded, they, created, through, weathering, erosion, granular, flow, stress, another, factor, formation, al. Alcoves is the geographical and geological term for a steep sided hollow in the side of an exposed rock face or cliff of a homogeneous rock type that was water eroded They are created through weathering erosion dry granular flow and stress Another factor in the formation of alcoves is winds between mid to late summer that steepen at the edge which leads to the failure and shaping of sand deposition in certain areas 1 Contents 1 Locations on Earth 1 1 North Pole 1 2 South Pole 2 Locations on Other Planetary Bodies 2 1 Mars 3 ReferencesLocations on Earth editNorth Pole edit nbsp An alcove in Entrada Sandstone near Moab Utah Although alcoves are both found in the northern and southern hemisphere more newly developed alcoves are in the northern hemisphere region Around the North Pole dune alcoves dune furrows and scarp avalanches can form 2 The mechanism dune furrows are formed are through cryo jets and many form at alluvial fans Furrows are channels and although mostly small they can vary in size and everytime they form in the spring season Furrows do not have a long lifetime as they are often blown away by strong summer winds South Pole edit In comparison the South Pole differs in having higher elevation which can cause changes in alcove formation These differences include the South Pole having older alcoves due to its denser deposition craters which are approximately 2 to 3 m thick which include particles of ice and minerals and craters that contains carbon dioxide ice 2 Both South Pole and North Pole alcoves are formed through stress cementing the sandstone particles together So after erosion at the area where the most rock has been excavated by weathering the pressure builds up and the sand particles become very stable and hold the arch above 1 Locations on Other Planetary Bodies editMars edit nbsp Alcoves with Alluvial Fans on Surface of Mars Annually in the North Pole region alcove formation is most active during autumn and winter seasons and also form specific alcove apron regions during springtime sublimation This is when the alcoves start at the edge of dunes and deposit and end into an apron fan shape 3 During summertime on Mars strong winds will blow away smaller less stable alcoves which starts the cycle for new alcoves to form the following autumn and winter It is estimated that alcove formation is responsible for a range of 2 to 20 of sand movement on Mars 3 References edit a b Bruthans Jiri Soukup Jan Vaculikova Jana Filippi Michal Schweigstillova Jana Mayo Alan L Masin David Kletetschka Gunther Rihosek Jaroslav 2014 Sandstone landforms shaped by negative feedback between stress and erosion Nature Geoscience 7 8 597 601 Bibcode 2014NatGe 7 597B doi 10 1038 ngeo2209 ISSN 1752 0908 a b Portyankina Ganna Aye K Michael 2018 Soare Richard J Conway Susan J Clifford Stephen M eds Chapter 6 CO2 Driven Geomorphological Processes Landscape Evolution Dynamic Mars Elsevier pp 187 205 ISBN 978 0 12 813018 6 retrieved 2023 03 18 a b Diniega Serina Hansen Candice J Allen Amanda Grigsby Nathan Li Zheyu Perez Tyler Chojnacki Matthew 2017 Dune slope activity due to frost and wind throughout the north polar erg Mars Geological Society Special Publication 467 95 114 doi 10 1144 SP467 6 PMC 5932633 PMID 29731538 nbsp This article about geography terminology is a stub You can help Wikipedia by expanding it vte nbsp This geology article is a stub You can help Wikipedia by expanding it vte nbsp This article related to topography is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Alcove landform amp oldid 1213140010, wikipedia, wiki, book, books, library,
