H2020Индивидуална стипендия2021–2023

MGFR · The (missing) fingerprints of Martian large-scale glaciations

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-09-06 → 2023-09-05
Финансиране от ЕС: 164 466 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Марсианските ледници и липсата на типични форми на релефа, като морени, се анализират чрез сравнение с земните ледници. Това помага да се разбере дали на Марс е имало течна вода под леда и къде да търсим обитаеми среди.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

The (missing) fingerprints of Martian large-scale glaciations

The surface of Mars is incised by thousands of valleys, evidence that the red planet harbored surface liquid water ~3.9-3.5 Byr ago, when life emerged on Earth. This climate optimum finished ~3.5-3 Gyr ago, marking the rise of a global hyperarid cryosphere. The transition between the early climate optimum and the current global cryosphere poses a significant question: why is the surface of Mars mostly devoid of glacial landforms? Indeed, liquid water should have remained stable under building glaciers and ice sheets, and there is evidence for liquid water action related to ground ice melt. But landforms characteristic of water-glacier interactions, such as moraines, grooves, or drumlins, are largely missing from Mars’ geological record. This has led scientists to believe that martian ice masses never hosted water underneath, rendering them unable to erode. However, work on the dynamics of terrestrial warm-based ice masses revealed a feedback between driving stresses and ice sliding. The lower surface gravity on Mars would hinder driving stress, but how this would affect glacial sliding on Mars had not been studied. The main objective of this project was to determine whether Martian glacial masses produce a different geological fingerprint from terrestrial ones. This discrepancy would imply that Martian ancient ice sheets harbored basal water, with implications for our search for water and habitable environments on Mars. Work follows three driving objectives (O1) Understanding the link between glacial landforms and underlying glacial dynamics. (O2) Explain why certain glacial landforms may be missing on Mars. (O3) Explore the role of martian glaciation through time under the perspective of ice dynamics.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Thousands of valley networks incise the Martian southern hemisphere, evidence that liquid water sculpted the Martian surface billions of years ago. This scenario contrasts starkly with the much colder and drier planet that Mars is nowadays, with frozen water accumulated on the polar caps and hundreds of mid-latitude glacial deposits, all frozen to the ground. In transit between these two climate scenarios, liquid water stability regions would have shifted to warmer, high pressure regions, and water would have accumulated beneath the growing ice masses, providing a stable environment for possible ancient life forms. Geological evidence for this transient period, however, is notoriously missing on Mars. Whereas the motion of glacial masses lubricated by subglacial meltwater (wet-based) produces arresting landscapes showing extensive linear substrate scouring on Earth, similar large-scale linear features are missing on Mars, leading to the historical interpretation that Martian ice masses were always frozen to the ground. The project presented here aims to revisit this idea adapting the physical framework describing terrestrial glacial hydrology to Mars, to show that the lower Martian surface gravity affects the dynamics of wet-based glaciers by favoring the emplacement of efficient meltwater subglacial drainage conduits, limiting ice sliding velocity, and producing different erosional fingerprints. Using mathematical models, analogue experiments, and geomorphological comparisons between Martian and terrestrial landforms, my objective is to show that the fingerprints of wet-based glaciation on Mars may be fundamentally different from those on Earth, challenging the current view and raising the possibility of a period of water stability under ancient Martian ice sheets. This project will help guide the search for ancient environments on Mars where water would have been stable, and where life could have existed shielded from the surface for extended periods of time.

Оригинален текст от CORDIS (на английски).

Участници

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS · ParisКоординаторФранция