Study suggests branching networks on surface of Mars due to heavy rainfall

June 28, 2018 by Bob Yirka, Phys.org report
Comparison of mean valley branching angles on Mars and arid landscapes on Earth. (A) Outlet locations of the valley networks mapped by Hynek et al. (orange) and Luo and Stepinski (rose color). Background shading indicates elevation. The corresponding branching angle distributions are shown in (B). The violet solid line represents the branching angle distribution in the Lower Green River, a basin in the arid southwestern United States. The modes of the three data sets are 36° for the Hynek and Hoke networks, 45° for the Luo and Stepinski networks, and 41° for the Upper Colorado-Dirty Devil basin (HUC 1407). These values are considerably smaller than the theoretical angle of 2π/5 = 72° expected for groundwater-driven network growth (black dashed line). Two sample valley networks on Mars are shown in (C) and (D). Scale bar corresponds to both sites. (E) Map of the Upper Colorado-Dirty Devil basin (HUC 1407), where the MDRS (red circle) is located. Credit: (c) Science Advances (2018). DOI: 10.1126/sciadv.aar6692

A trio of researchers with ETH Zurich and the University of Chicago has found evidence that suggests narrow channel networks seen on the surface of Mars are due to heavy rainfall runoff. In their paper published on the open access site Science Advances, Hansjoerg Seybold, Edwin Kite and James Kirchner describe their study of the channel networks and comparisons they made with similar formations found here on Earth.

As the study notes, prior study of narrow networks on Mars has led researchers to believe they were likely created by a standing body of water. Other possibilities include groundwater sapping, fluvial runoff or even ice melting. Lack of direct evidence supporting any of the theories, however, has led to continuing debates. The researchers with this new effort have jumped into the fray by suggesting an alternative theory based on observations of Earth geography. They suggest work done by other researchers studying channel networks here on planet Earth offers a blueprint for the origins of channels on Mars. In that prior effort, other researchers had discovered a connection between the dryness of an area and the branching angles characteristic of some channel networks. Those in more arid areas, they found, tended to branch at narrower angles than did those in places exposed to more rainfall.

To find out if such evidence might be applicable to Mars, the researchers studied datasets containing information regarding the channel branching seen on Mars. In comparing two datasets from separate studies, they found similarities in descriptions of branching angles on Mars, both of which were compatible with the findings by the team studying channel networks on Earth—namely, that they had narrow angles. This, the researchers suggest, indicates a similar process was involved.

On Earth, the narrow channels resulted from infrequent runoff. Successive rainfalls led to deepening of the channels to their current depth. The researchers suggest the same is likely true for the branching networks on Mars. Rather than being formed by subtle movements of groundwater, they were likely carved into the ground by rushing water. Such an occurrence, they further note, would suggest that Mars had a very active hydrologic cycle.

The central portion of Osuga Valles, which has a total length of 164 km. In some places, it is 20 km wide and plunges to a depth of 900 m. Credit: Photograph: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Explore further: Recent work challenges view of early Mars, picturing a warm desert with occasional rain

More information: Hansjoerg J. Seybold et al. Branching geometry of valley networks on Mars and Earth and its implications for early Martian climate, Science Advances (2018). DOI: 10.1126/sciadv.aar6692

Abstract
Mars' surface bears the imprint of valley networks formed billions of years ago. Whether these networks were formed by groundwater sapping, ice melt, or fluvial runoff has been debated for decades. These different scenarios have profoundly different implications for Mars' climatic history and thus for its habitability in the distant past. Recent studies on Earth revealed that valley networks in arid landscapes with more surface runoff branch at narrower angles, while in humid environments with more groundwater flow, branching angles are much wider. We find that valley networks on Mars generally tend to branch at narrow angles similar to those found in arid landscapes on Earth. This result supports the inference that Mars once had an active hydrologic cycle and that Mars' valley networks were formed primarily by overland flow erosion, with groundwater seepage playing only a minor role.

Press release

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Nik_2213
5 / 5 (1) Jun 28, 2018
Flash floods ??
Surveillance_Egg_Unit
5 / 5 (3) Jun 29, 2018
The photo slightly resembles abstract art in a lighter sepia tone, if I remember my colors. Very nice, although so desolate and nightmarish reminiscent of a medusa head.

Yes. Flash floods very likely from higher elevations coming down into the valleys in a torrent to form the channels like a sluice that is used for panning for gold. It washed away the lighter weight regolith down through the channels already cut by the first rush of liquid water. It cut deeper until the water hit bedrock. Clearly, the lack of vegetation and trees to absorb the force of the water rushing down from higher elevations made an unobstructed path for liquid water to change the features of the landscape/terrain.

Heavy rains could have caused what would have been devastation had it been on a Terran valley.
Either melting glaciers in the Martian summer, or heavy rainfall could have caused it. But where did the bulk of the water go?
I regard the planet as the fabled Sheol...or hell.

rrwillsj
2.3 / 5 (3) Jun 29, 2018
This rover scraped up some samples. That rover a 1000 KMs away scraped up some samples. The surveyor in orbit, took photos & scanned the surface of a different hemisphere.

Each of the three research teams excitedly announces their definitive conclusions to the small bit of data they had collected. Each of the three conclusions contradict the other. Each of them are reasonably correct for the specific location that they had probed.

The embarrassment comes in trying to use their findings as evidence that each teams separate findings can explain the global history of Mars. Even as they contradict one another.

Different marsographical sites, revealing data about separate events, separated by billions of years of activities.

How could anyone possibly misunderstand such a confusion of information?
TheGhostofOtto1923
1 / 5 (1) Jun 30, 2018
This rover scraped up some samples. That rover a 1000 KMs away scraped up some samples. The surveyor in orbit, took photos & scanned the surface of a different hemisphere.

Each of the three research teams excitedly announces their definitive conclusions to the small bit of data they had collected. Each of the three conclusions contradict the other. Each of them are reasonably correct for the specific location that they had probed.

The embarrassment comes in trying to use their findings as evidence that each teams separate findings can explain the global history of Mars. Even as they contradict one another.

How could anyone possibly misunderstand such a confusion of information?
Ahahaaa the psychopath reads one physorg article and thinks he has enough info to criticize teams of actual scientists who have been working on the subject for years.

Could a dumbass be any dumber???
TheGhostofOtto1923
1 / 5 (1) Jun 30, 2018
"He does bizarre and self-destructive things because consequences that would fill the ordinary man with shame, self-loathing, and embarrassment simply do not affect the psychopath at all. What to others would be a disaster is to him merely a fleeting inconvenience."
rrwillsj
3 / 5 (2) Jul 01, 2018
deer ottotrumpeting.

I finf it hilarious that you are the Nietzschean fanboy. Grovelling before his twaddle.

While simultaneously criticizing me for actually "applying" his philosophy of germanic bourgeoisie gibberish.
rrwillsj
3 / 5 (2) Jul 01, 2018
Wait! Wait! I got it!
Brit comedian talking to the Brit nightclub owner. Wondering if his jokes were too risque for the club's patrons.
The owner reassured him "Where would we British be without a sense of humor?
The comedian retorted "Germany?"
yaridanjo
not rated yet Jul 07, 2018
Comet swarms form frequently and last a million years or so. The average period is 3313 years and there are at least five swarms, some with multiple sub clusters. Some of these Kuiper Belt bodies are rich in water. This is where Earth got its water from. The,swarms are not always present, but they are present often enough to water Mars occasionally.
http://barry.warm...led.html
VULCAN (Planer Nine) REVEALED
See:
http://barry.warm...led.html#8
EARTH OFTEN HIT WHEN METEOR/COMET SWARMS PASS BY

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