Debris flowing on frozen Arctic sand similar to seepage flows on Mars
Washington: A team of researchers have demonstrated that frozen water in the form of snow or frost can melt to form debris flows on sunward-facing slopes of sand dunes in the Alaskan arctic at air temperatures significantly below the melting point of water.
The debris flows consist of sand mixed with liquid water, which cascade down steep slopes.
Southwest Research Institute (SwRI) scientists made their observations at the Great Kobuk Sand Dunes, in Kobuk Valley National Park, Alaska.
This site serves as an Earth-based cold-climate "analog" to dunes on Mars. Debris flows formed on days when air temperatures measured continuously by the team remained below the melting point of water.
Very few minutes of above-freezing ground surface temperatures are needed to locally melt frozen water and mobilize sand down steep slopes.
The scientists hypothesize that fresh patches of wind-deposited dark sand on bright white snow caused local hot spots to form where solar radiation was absorbed by the sand and conducted into the underlying snow.
This enabled meltwater to briefly form and sand to be mobilized despite subfreezing local air temperatures. A similar mechanism may be responsible for triggering debris flows on frozen Martian sand dunes.
The Alaskan debris flows formed at ground temperatures that may correspond to those occurring locally and seasonally on the surface of Mars, said hydrogeologist Dr. Cynthia Dinwiddie, a principal engineer in SwRI`s Geosciences and Engineering Division.
The Alaskan debris flows are morphologically similar to small, defrosting-related "dark dune spot" seepage flows that seasonally form in late winter on frost-covered Martian sand dunes.
More from India
More from World
More from Sports
More from Entertaiment
- India- America joint military exercise begins in Ranikhet
- Exclusive: This is what Kashmir's stone pelters have to say!
- India to activate laser walls on LOC to stop infiltration
- Panel discussion on 'Most Favoured Nation' status India accorded to Pakistan in 1996
- Will India's SAARC summit boycott change Pak's attitude towards terrorism?
- SETBACK! Sedition case against 200 Congress workers for shouting 'Pakistan Zindabad' slogans during rally for Uri martyrs
- Did Arvind Kejriwal tweet in favour of Pakistan over Uri attacks? Here is what Twitter says
- WATCH: At 430/9, India needed 24 runs to avoid follow on. What Kapil Dev did next will blow your mind!
- Rameez Raja picks all-time XI - Three Indians, but just one Pakistani make it to the list
- This Hindu-dominated village in West Bengal is not allowed to organise Durga Puja as Muslims don't want it