Volcanic eruptions are not a major threat to the Martian landscape, but an area about the size of Alaska was potentially covered with lava as recently as one million years ago. The findings are detailed in a study published December 15 in the Journal of Geophysical Research: Planets and reveal that the presence of large fissures could have resulted in major flooding events. The reactions from the mixture of lava and water from the floods may have created an environment that could harbor life.
[Related: Giant quake that shook Mars for hours had a surprising source.]
Planet Earth is home to very active plate tectonics and these constantly churning chunks of crust alter our planet’s surface. Mars has long been considered a geologically “dead” planet due to its lack of plate tectonics and volcanic activity has never been observed there. However, some recent discoveries have questioned the notion that Mars was always this way, including evidence that a giant mantle plume underneath the region of Elysium Planitia was once behind intense seismic and volcanic activity in the planet’s relatively recent past. Elysium Planitia has the youngest terrain on the Red Planet, so studying it helps scientists better understand its past, including more hydrological and volcanic events.
In this new study, a team from the University of Arizona and the University of Alaska Fairbanks, combined images taken with NASA’s Mars Reconnaissance Orbiter and measurements from ground-penetrating radar to recreate a 3D model of every individual lava flow they could detect evidence of in Elysium Planitia. The survey revealed more than 40 volcanic events in the planet’s recent past. One of the largest flows possibly filled a Martian valley named Athabasca Valles with almost 1,000 cubic miles of basalt.
“Elysium Planitia was volcanically much more active than previously thought and might even still be volcanically alive today,” study co-author and planetary geologist Joana Voigt said in a statement. Voight completed this research as part of her PhD at the University of Arizona and is now postdoctoral researcher at Caltech’s Jet Propulsion Laboratory.
The Marsquakes recorded by NASA’s InSight lander between 2018 and 2022 also provided the team on this study with further proof that the Red Planet is not so dead just below the surface.
“Our study provides the most comprehensive account of geologically recent volcanism on a planet other than Earth,” study co-author and University of Arizona planetary geologist Christopher Hamilton said in a statement. “It is the best estimate of Mars’ young volcanic activity for about the past 120 million years, which corresponds to when the dinosaurs roaming the Earth at their peak to present.”
These study’s findings have implications for future research into whether Mars harbored life at some point in its history. Elysium Planitia has traces of several large floods and the interaction of the outpouring lava with flood water or ice likely shaped the landscape in dramatic ways. The team found evidence of steam explosions across Elysium Planitia. Astrobiologists are interested in these types of interactions, as they may have created hydrothermal environments that were conducive to microbial life.
For a closer look, the team used images taken with the Context camera onboard the Mars Reconnaissance Orbiter and other images from the orbiter’s HiRISE camera in selected areas. They also used data records from the Mars Orbiter Laser Altimeter aboard NASA’s Mars Global Surveyor. They then combined the images with survey data taken with NASA’s Shallow Radar (SHARAD) probe.
[Related: Mars rover snaps pics of dusty craters that may have once roared with water.]
“With SHARAD, we were able to look as deep as 460 feet below the surface,” said Voigt. “Combining the datasets allowed us to reconstruct a three-dimensional view of the study area, including what the topography was like before lava erupted from multiple cracks and filled basins and channels previously carved by running water.”
This detailed reconstruction of Mars’ geological features provides scientists a peek into the processes that shaped its past. Understanding the relationship between the planet’s volcanoes and crust is a key to recreating the planet’s paleo-environmental conditions. In addition to water from within the magma being flung into the Martian atmosphere and then freezing on the surface, eruptions can also allow for major releases of groundwater onto the surface.
The team plans to continue to use complex datasets obtained with various imaging methods to build more detailed insights of the Martian surface and what lies beneath.
According to Voigt, lava flow surfaces are similar to “open books that provide a wealth of information about how they came to be if you know how to read them. These areas that used to be considered featureless and boring, like Elysium Planitia, I think they contain a lot of secrets, and they want to be read.”