A new analysis of Martian data once again suggests that an intermittent ocean once existed in the planet’s northern hemisphere, and that it was fed by catastrophic floods coming down from the volcanoes through Marineris Valles.
“Our simulation shows that the presence of the sea would have attenuated cataclysmic floods, leading to shallow spillovers that reached the Pathfinder landing site and produced the bedforms detected by the spacecraft,” said [lead scientist Alexis Rodriguez].
The team’s results indicate that marine spillover deposits contributed to the landscape that the spacecraft detected nearly 22 years ago, and reconcile the mission’s in situ geologic observations and decades of remote-sensing outflow channel investigations.
The sea bears an uncanny resemblance to the Aral Sea on Earth in that in both instances they lack distinct shoreline terraces. Its rapid regression over shallow submerged slopes resulted in rates of shoreline front retreat too fast for the terraces to form. The same process could partly account for the long-recognized lack of northern plains shorelines.
“Our numerical simulations indicate that the sea rapidly became ice-covered and disappeared within a few thousand years due to its rapid evaporation and sublimation. During this time, however, it remained liquid below its ice cover,” said PSI Senior Scientist Bryan Travis, a co-author in the paper.
The map above shows the outlet region to the west and north of Marineris Valles. (The paper from which it is adapted is available on line here.) It shows that inland sea, created by the catastrophic floods. Because it sits at a lower elevation than the plains to the north, the floods that entered it ponded there, where they dried up. Only when the floods were at their highest did the water spill out into the northern plains.
In reading the paper, it confirms many of the suppositions I myself have made in my frequent posts analyzing numerous Mars Reconnaissance Orbiter (MRO) images, such as the lack of a clear shoreline because the ocean was short-lived. As it dried up its edge left patches of shoreline, at different elevations and in pondlike patterns, almost like the beach debris left behind by the tide.
The paper also shows that some of my guesses were not quite correct. For example, this new analysis says that the catastrophic floods only partly carved out the chaos terrain of Hydraotes Chaos, rather than do it all as I supposed here. Instead, the floods contributed, but much of the erosion occurred when the short-lived inland sea existed here, eroding away at the mesas from all sides.
Read it all. Though this remains a simulation based on what is presently very incomplete data and thus has many uncertainties, it will give you a much deeper understanding of what we presently theorize about the past geological history of Mars.
Now available in hardback and paperback as well as ebook!
From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.
Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space
, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.
does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.
“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.
All editions are available at Amazon, Barnes & Noble, and all book vendors, with the ebook priced at $5.99 before discount. The ebook can also be purchased direct from my ebook publisher, ebookit, in which case you don't support the big tech companies and I get a bigger cut much sooner.
Autographed printed copies are also available at discount directly from me (hardback $24.95; paperback $14.95; Shipping cost for either: $5.00). Just email me at zimmerman @ nasw dot org.