Generally speaking, the weight and movement of glaciers will carve unique valleys and fjords on the surface, but Mars lacks similar landforms, so researchers believe that ancient glaciers on Mars must be firmly frozen on the ground, but new research data shows that glaciers are not fixed in place , just moving very slowly.
Earth’s glaciers and meltwater under the ice sheet gather together to lubricate the lower edge of the glacier and affect the speed of the glacier’s movement. The new study simulates how the low-gravity environment of Mars affects the sliding speed of the ice sheet and the relationship between how the water under the ice is lost. possibility.
Although Mars has no distinct U-shaped valleys, researchers have found other ice masses that resemble glaciers in the past, including gravel ridges called eskers and potential subglacial channels. Earth will see Drumlins, lineations, scouring marks, and moraines.
The research team simulated two identical ice sheet dynamic environments on Earth and Mars, and adapted existing physical models to match Martian conditions to understand the influence of subglacial drainage, glacier sliding speed, and degree of erosion. The researchers believe that the interaction between ice cubes and basement water must have occurred at some point, from early Mars with surface liquid water, extensive ice sheets and volcanic activity to the current state of global freezing. It is difficult to believe that the history of Mars is 4 billion years old. Mars has never developed subglacial water ice caps because it is a planet with large water reserves, highly variable topography, volcanic activity, and is farther from Earth than the Sun.
Simulation data show that compared with Earth, Martian glaciers absorb basement meltwater more effectively, prevent the lubrication of the bottom layer of the ice sheet to a large extent, and indirectly reduce the rate of sliding and glacier erosion. Therefore, the typical glacial terrain found on Earth will not form on Mars. , the authors reasoned, the simulations could also speculate on the effects of ancient life forms, ice sheets that provide a steady water supply, protect and stabilize any subglacial water bodies, and resist solar radiation in the absence of a magnetic field. The new study was published in Geophysical Research Letters.
(This article is reproduced with permission from the Taipei Planetarium; the first picture is the current Martian glacial terrain. Source: NASA)
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