00:00In high-latitude permafrost environments and high-altitude mountains, there are a large
00:12number of mysterious regular surface patterning, also known as patterning, such as the Qinghai
00:19Tibet Plateau and other freezing regions in China.
00:24The Svalbard Islands in Norway in the Arctic and the Alpine regions in Ethiopia.
00:32The patterned ground is made up of different kinds of stones and soils.
00:36Some arranged in polygonal net, stone circles, and others in strapped spatial patterns.
00:45The origin of these regular patterns has long been puzzling scientists, but recently this
00:51enigma is starting to be solved.
00:57Scientists now attribute the spontaneous regular patterns to a process called spatial self-organization.
01:05In the periglacial environment, when scouring together with soil freezing thorn cycles are
01:11speculated to drive the aggregation and separation movements of granular particles in the soil,
01:19which eventually result in assorted spatial patterns of stones on the land surfaces.
01:32This idea has been sparked by theoretical and empirical studies in physics, chemistry, biology,
01:40and ecology.
01:41However, it is notoriously difficult to test this idea in the field.
01:46The geomorphological systems in cold regions often evolve at extremely slow rates, largely
01:54forbidden human observers to record the processes.
01:57Many existing numerical models have suggested that differential frost heave and radial expansion
02:05of the fine-grained soils can lead to the movement of surface particles to the margins of the plugs
02:11and the formation of the self-organized patterns.
02:15This mechanism can reproduce a variety of large-scale sorted patterns, such as polygons and sorted circles.
02:24But direct experimental evidence for this model is still lacking.
02:28Scientists have long speculated that needle eyes formed in the permaforous layer could play a role.
02:35A new research led by an international team from China, Japan, the US, and the Netherlands revisited this old idea
02:45with brand new evidence and theory.
02:47The researchers designed an elegant experiment system that allows for the formation of needle eyes
02:55in well-controlled lab conditions.
02:57This system can mimic a time machine with which the observers can push the fast-forward button
03:04to speed up the process of land surface evolution within a microcosm.
03:09Within a couple of weeks, the researchers can now observe the years or even decades-long process happening in nature.
03:18They use video camera and computer program to automatically track the movement trajectory of every single stone
03:26and reproduce such observed processes in computer with mathematical models.
03:31The researchers found that, driven by the freezing thong cycles in soils,
03:36the surface granular particles migrated towards the stone-rich areas from stone-poor areas.
03:42This is exactly the process where a variety of order spatial patterns of stones arises from.
03:50This group of scientists have replicated the experiment numerous times,
03:55with all kinds of settings of needle eyes properties and stone field concentration.
04:00They put together these nonlinear relationships between different needle eyes height and stone field concentration
04:07to demonstrate that the geomorphological pattern formation process has the same physical principle,
04:13as that underpins the water-oil separation process.
04:16The essence of the stone field is that the stone field from the geomorphism to the high-rolo-do movement.
04:21The movement of the geomorphism is different from the geomorphism.
04:22This movement of the geomorphism is different from the geomorphism.
04:26Known as phase separation mechanism, the phase separation theory perfectly reproduced the different types of sorted patterns,
04:34and found that the activity of needle eyes plays a dominant role in shaping this pattern ground.
04:40What makes the scientists more exciting is that their phase separation model can also perfectly reproduce the similar sorted patterns
04:49found in the Martian boulders by curiosity.
04:53Can this be seen as another evidence, reinforcing the existence of soil water on Mars?
04:59Does this mean freezing thong cycles also drive the evolution of Martian landscapes?
05:06It's still too early to answer this question.
05:10But this study does open many opportunities to look into geological and geomorphic evolution of Earth-like planets.
05:18This study does open many opportunities to look into geomorphism in the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorphism of the geomorph
