The 2014–2015 Holuhraun lava flow-field in Iceland as a planetary analog for young volcanic terrains in Elysium Planitia, Mars

Abstract

Elysium Planitia is the youngest volcanic terrain on Mars, and the only region that exhibits evidence of ongoing magmatic activity today. This makes Elysium Planitia crucial for understanding the tectonic, magmatic, volcanic, and thermal state of the planet. The 2014–2015 Holuhraun eruption in the Icelandic Highland provides a unique opportunity to study a large-volume, fissure-fed eruption—with associated lava–water interactions—that serves as a terrestrial analog for volcanic terrains in Elysium Planitia. Here, we detail the key similarities between the Holuhraun and Elysium Planitia sites, including their geological settings, prominent lava morphologies, and implications for inferring eruption dynamics. Even in the absence of global plate tectonics on Mars, both locations exhibit young fissure systems, indicating an extensional tectonic setting. Detailed investigations of lava morphologies offer valuable insights into the dynamics and evolution of fissure-fed eruptions. Of particular importance are “transitional” lavas, which, at the Holuhraun site, are associated with different effusion rates and eruption stages. The presence of inflation features with disrupted surfaces in Elysium Planitia supports the interpretation that these are rubbly lava flows formed in association with high local strain rates, implying an initial high effusion rate. However, both locations exhibit polygonal terrain, which is indicative of low strain rate conditions, implying a change to cooling under broadly stagnant conditions. Due to its variety of recent geologic processes, including volcanic and potentially aqueous flows, the presence of pristine surfaces, as well as associated tectonic and magmatic activity, Elysium Planitia is a compelling target for future exploration.