European researchers, including Dr Manish Patel, Dr Matt Balme and Dr Matthew Sylvest from The Open University(OU), have found that mud volcanoes on Mars may look similar to lava flows found on Earth.
According to a study, published in Nature Geoscience, mud flows exposed to the low atmospheric pressures found on Mars will behave similar to lava flows in Hawaii or Iceland, also known as pahoehoe flows.
Thousands of volcano-like landforms associated with lava-like flows dot the surface of Mars. Some have been attributed to magmatic volcanism. These landforms occur in terrains covered by sediments thought to have been deposited by ancient floods, and the rapid burial of wet sediments could have resulted in mud volcanism.
However, little is known about how mud would flow on Mars, due to the complexity of performing these experiments in the laboratory.
Simulating Martian conditions on Earth
A team of researchers decided to address the knowledge gap and investigate the lava-like flows on Mars. Using the Dr Patel’s state-of-the-art low-pressure Mars Chamber, Dr. Petr Brož from the Institute of Geophysics of the Czech Academy of Sciences led a team of scientists as they performed a set of ‘novel’ experiments – the kind of experiments that nobody else would probably want to do in their facilities.
The team poured a water-rich mud over a cold sandy surface in the low-pressure chamber and multiple cameras recorded the results. These experiments were designed to simulate the hostile Martian conditions revealing how the instability of water within the mud changes the mud’s behaviour.
Researchers found that under the low atmospheric pressure and low temperatures of the Martian surface, mud flows would end up looking similar to pahoehoe flows on Earth.
Mud volcanism rather than magmatic activity
Dr Manish Patel, Senior Lecturer in Planetary Sciences at The Open University, explains:
“Most people assume hot magmatic volcanic activity created all the features we see on Mars, but it looks like some of them may in fact be due to mud volcanism – meaning a potentially different geological history for Mars in terms of assumed volcanic activity.
“This is a great example of how a seemingly bizarre idea for an experiment in a lab can revolutionise our interpretation of the features on another planet. Bold ideas for experiments like Petr’s lead to new understanding.”
The Martian atmosphere is very thin, it is around 150 times less than the atmosphere of Earth, and this has significant consequences. Under such surface pressure water is not stable and begins to boil and evaporate. The evaporation removes latent heat from the mud, eventually causing it to freeze.
The team showed that the experimental mud flows spread like terrestrial pahoehoe lava flows, with liquid mud inside the flow spilling out from ruptures in the outer frozen muddy crust, then refreezing to form a new flow lobe. This finding suggests that mud volcanism can indeed operate on the surface of Mars.
Martian mud volcanoes vs. terrestrial volcanoes
However, Martian mud volcanoes may be substantially different in shape from terrestrial ones. Therefore, at larger scales, mud volcanoes on Mars may look very different from their terrestrial equivalent. This work has wider implications, since similar processes may apply to cryovolcanic extrusions on icy bodies in the Solar System.
Dr. Petr Brož from the Institute of Geophysics of the Czech Academy of Sciences, comments:
“This is a very exciting and unexpected result. We have a tendency to expect that geological processes, like mud movement, would be operating elsewhere in the Solar system in a similar fashion as on Earth. This is based on our everyday experiences. However, our experiments clearly show that in reality, this simple process which we all know from our childhood would be very different on Mars.”
For more on the study read the paper published in Nature Geoscience.