Evidence of Multiple Past Ice Ages Found on Mars

Evidence of extensive glaciation in Deuteronilus Mensae, Mars: Inferences towards multiple glacial events in the past epochs

Authors:

1. Rishitosh K. Sinha (a)
2. S.V.S. Murty (a)

Affiliation:

a. PLANEX, Physical Research Laboratory, Ahmedabad 380009, India

Abstract:

In this study, we examine the existence of multiple episodes of glacial activities in Deuteronilus Mensae region on Mars from the analysis of high-resolution remote sensing images acquired by Mars Reconnaissance Orbiter (MRO) ConText Camera (CTX) and High resolution imaging science experiment (HiRISE). The investigated portion from northern mid-latitude of Mars is centered at 44.6° N and 28.8° E and lies ∼200 km to south of the largest crater (Lyot) of northern plains. We have critically examined the features on the surface of regional aprons and suggested a possible process by which these formations would have resulted. The entire morphology of the surface was mapped using CTX data sets for developing a general idea about the class of landforms and their extent. The topographic characteristics of the region were derived from Mars Orbiter Laser Altimeter (MOLA) data sets to assess the down-slope flow of ice-debris mixture and the local slope-variations were determined to interpret the flow of small-scale features. The degradational extent of craters lying on the surface of linear valley fill (LVF) flow and the formation of layered pit units in the low-lying region of plateau 2 were systematically explained to account for the presence of ice in the near surface beneath the debris apron. The examined flow-features on the apron surface were compared with their terrestrial glacial analogues for deducing the possible explanation for the variation in pattern of LVF flow. Processes resulting in similar type of glacial landforms as in Antarctica and parts of Alaska on Earth were widely identified and attributed to be the major cause that has led to shape the fretted terrain on Mars. We have also attempted to classify the different stages of Martian glacial activity, based on the nature of landforms observed in the study region. The morphological evidences and comparisons between the features on Earth and Mars ascertained that Mars has experienced extensive glaciation during the past, and has preserved the landforms on its surface resulting from multiple glacial epochs.