Factors other than trapped ice limit dune movement on Mars
July 8th, 2009 - 12:03 pm ICT by ANIWashington, July 8 (ANI): A study has determined that snow and ice trapped inside dunes on Mars does not entirely stop their movement, a finding which indicates that other factors are limiting the dune movement.
Planetary scientists have monitored some Martian sand dunes for more than 30 years, and the dunes have not moved during that time, leading scientists to question whether snow and ice trapped inside the dunes might be preventing movement.
However, a recent study, led by Mary Bourke, a senior research scientist at the Tucson-based Planetary Science Institute, shows that snow and ice are not enough in themselves to stop dune movement.
While trapped ice and snow impedes movement of sand dunes in polar climates, compared to their counterparts in warmer areas, this does not entirely stop dune movement, the study shows.
“This indicates that other factors are limiting dune movement,” said Bourke.
Bourke also showed that two small dunes recently disappeared on Mars. The dunes, which were 20 meters wide (about 65 feet) and located in the north polar region of Mars, were completely eroded away over a period of 5.7 Earth years.
“This (dune disappearance) is fantastic new data, showing that sand is transported on Mars where and when the wind energy is available,” Bourke said. “But the bigger, larger dunes on Mars are not moving, at least in the areas we studied,” she added.
In the most recent study, Bourke and her colleagues used vertical aerial photos and LiDAR (Light Detection and Ranging) data to estimate dune migration rates in Antarctica’s Victoria Valley dune field.
The photos, taken between 1961 and 2001, came from the USGS Antarctic Resource Center.
These dunes are known to be covered by seasonal snowfalls and have snow and ice layers trapped inside.
Bourke found that the dunes migrated about 1.5 meters (5 feet) per year, which is small compared to the distance covered by dunes in warm deserts, which can be as high as 30-70 meters (about 100 to 230 feet) a year.
Factors limiting dune movement on Mars would include the planet’s thin atmosphere, which requires very high wind speeds to provide the force needed to move sand, and the water and carbon-dioxide frosts that cover dunes in Mars’ polar regions for 70 percent of the year. (ANI)
- Sand dunes in Northern Mars actively changing - Feb 04, 2011
- Scientists create first detailed maps of dry ice deposited in Martian polar regions - Sep 16, 2009
- Experts may reach bottom of Antarctic lake in 2014 - Feb 09, 2012
- Bubble wrap used on slopes of Scotland to prevent snow from melting - Apr 18, 2011
- Disappearing ice altering ecosystem subtly - Apr 09, 2012
- Arctic region warming fastest on earth - Jul 04, 2011
- Man survive two months in car in -30C - Feb 20, 2012
- Trees on Mars? - Jan 13, 2010
- Warming ocean layers melt polar ice sheets faster - Jul 04, 2011
- How beach beetles use wheel locomotion to roll away from danger - Mar 24, 2011
- Mars had complex hydrological past, reveals new evidence - Dec 17, 2009
- Scientists spot earth-like snowy avalanches near Mars north pole - Nov 08, 2008
- Frozen piles of CO2 on Mars may trigger avalanches - Oct 30, 2010
- Titan's surface similar to that of Earth - Aug 07, 2009
- Britain to get colder winters due to climate change: Experts - Dec 25, 2010
Tags: aerial photos, antarctica, colleagues, counterparts, disappearance, dune field, martian sand dunes, migration rates, planetary science institute, planetary scientists, polar climates, polar region, research scientist, resource center, snow and ice, snowfalls, usgs, victoria valley, warm deserts, wind energy