Ian Flynn’s research on Mars’ lava buildup was highlighted by the journal Icarus

Pitt researchers have for the first time identified a pattern of lava buildup on Mars that mirrors those found on some Earth volcanoes. These findings landed them the cover story of the December 2024 issue of the journal Icarus. The lava patterns found on Mars, known as spatter cones, are the result of lava that was ejected in an eruption, then landed on the ground and cooled. As more lava is ejected, it continues to pile up in the telltale shape.

“You know at the beach, when you have a handful of wet sand and you let it dribble down to the ground? It kind of looks like that,” said lead author Ian Flynn, a research assistant professor in the Department of Geology and Environmental Science in the Kenneth P. Dietrich School of Arts and Sciences. 

With Erika Rader at the University of Idaho, Flynn (A&S ’22G) compared the patterns found from a volcano that erupted on Mars in the Amazonian Period — about 2.9 billion years ago — to the aftermath of the 2021 Fagradalsfjall eruption in Iceland, confirming the structures were indeed spatter cones.

A different pattern, called scoria cones, have been spotted on Mars previously. The different patterns indicate different conditions within the volcano and in the atmosphere at the time of eruption. Finding spatter cones for the first time gives researchers new insights into the magma and gasses released from Martian volcanoes. They also tell researchers about relative temperatures at the time of each eruption.

[Read more about Flynn’s volcanic research.]

For spatter cones to form, the rate of cooling must have been between 7 and 14 degrees Celsius per minute. Had the lava cooled too slowly, it would not have solidified and would instead have flowed farther along the landscape. Had it cooled too quickly, scoria cones would have formed instead.

 “Historically, we thought these features on Mars were similar to what we see in Hawaii,” where magma bubbles up to the surface and flows across the landscape, Flynn said. “This shows us we’re actually seeing something more similar to Iceland: hybrid eruptions,” which involve magma slowly making its way to the surface and explosive eruptions with high gas content.

This work will do more than clarify questions about volcanism on Mars. Flynn’s co-author Rader knew that spatter cones could only be found in a narrow range of cooling rates. “That made me think about the significance of this volcanic feature in the bigger narrative of the mars environment,” Flynn said.

Now that he’s found the spatter cones, his colleagues can use this new information and relate it to questions of climate on Mars

“You’ve got to do baby steps first before you can start to determine how these things are related.”