Ancient Oceans on Mars Could Have Formed After Massive Volcanic Eruptions: Research

Ancient Oceans on Mars Could Have Formed After Massive Volcanic Eruptions: Research

The shallow oceans on Mars could have formed due to massive volcanic eruptions on the Red Planet in the past, suggests a new research paper released by University of California, Berkeley researchers. Scientists suggest that shoreline-like structures on Mars could have been formed due to shallow oceans but there wasn’t an easy explanation about where the water disappeared. The research paper published in the journal Nature also points that massive volcanic eruptions could have changed the climate to such an extent that water couldn’t exist in liquid form.

Tharsis, a gigantic volcanic region of the planet, could be behind the formation of oceans on the planet. Tharsis region also supports Olympus Mons, the largest and most famous volcano in the solar system. Professor Michael Manga, a planetary scientist at the University of California, Berkeley led the current research. Professor Manga said, “Volcanoes may be important in creating the conditions for Mars to be wet. Shallow oceans could have formed around 3.7 billion years ago. This formation was linked to the creation of Tharsis, a 5,000-kilometre-wide structure containing some of the largest volcanoes in the solar system.”

Volcanic eruptions could have also created channels for underground water to fill the northern plains on the Red Planet. The unusual shorelines on the surface of planet Mars have been difficult to explain till date. While these structures certainly look like dried-up shorelines, they are very irregular – varying in height by as much as a kilometre. Normally coastlines are fairly constant in their elevation, so this has perplexed researchers looking for evidence of ancient oceans.

Astronomers believe that oceans on Mars emerged after many volcanic eruptions in the Tharsis region. “The assumption was that Tharsis formed quickly and early, rather than gradually, and that the oceans came later,” Professor Manga added.

Tharsis region also comprises of three enormous shield volcanoes Arsia Mons, Pavonis Mons, and Ascraeus Mons, which are collectively known as the Tharsis Montes. Tharsis is divided into two broad rises, a northern and a larger southern rise. The northern rise partially overlies sparsely cratered, lowland plains north of the dichotomy boundary.

Spacecraft exploration over the last two decades has shown that volcanoes on other planets can take many unexpected forms. However, volcanic activity on Mars could also explain the shoreline of small oceans on the Red Planet. Volcanoes may be important in creating the conditions for Mars to be wet.

The research paper further informed...

The model also counters another argument against oceans: that the proposed shorelines are very irregular, varying in height by as much as a kilometer, when they should be level, like shorelines on Earth.

This irregularity could be explained if the first ocean, called Arabia, started forming about 4 billion years ago and existed, if intermittently, during as much as the first 20 percent of Tharsis’s growth. The growing volcano would have depressed the land and deformed the shoreline over time, which could explain the irregular heights of the Arabia shoreline.

Similarly, the irregular shoreline of a subsequent ocean, called Deuteronilus, could be explained if it formed during the last 17 percent of Tharsis’s growth, about 3.6 billion years ago.

But scientists can do more precise dating of Tharsis and the shorelines to see if it holds up. NASA’s next Mars lander, the InSight mission (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport), could help answer the question. Scheduled for launch in May, it will place a seismometer on the surface to probe the interior and perhaps find frozen remnants of that ancient ocean, or even liquid water.