講演情報
[PPS04-P20]Geomorphological Evidence of Ice Activity on Mars Surface at Mid-Latitudes
*Marco Moro1、Adriano Nardi1、Matteo Albano1、Monica Pondrelli2、Antonio Piersanti1、Michele Saroli3,1、Beatrice Baschetti4,5、Erica Luzzi6、Lucia Marinangeli7、Nicola Bonora3 (1. Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy、2.Dipartimento di Ingegneria e Geologia, International Research School of Planetary Sciences, Università d’Annunzio, Viale Pindaro 42, 65127 Pescara, Italy、3.Dipartimento di Ingegneria Civile e Meccanica, Università degli Studi di Cassino e del Lazio Meridionale, Via G. di Biasio 43, 03043 Cassino, Italy、4.Istituto Nazionale di Astrofisica (INAF)-IAPS, Via del Fosso del Cavaliere 100, 00133 Rome, Italy、5.Dipartimento di Geoscienze, Università degli Studi di Padova, Via G. Gradenigo 6, 35131 Padua, Italy、6.Mississippi Mineral Resources Institute, The University of Mississippi, 49 Brevard Hall University, University, MS 38677, USA、7.Dipartimento di Scienze Centro Ud’A Terra-Mare, Università d’Annunzio, Via Vestini 31, 66013 Chieti, Italy)
キーワード：
Mars、ice、Ismenius Lacus、HiRISE、CTX、Photointerpretation
Extensive radar investigations, observed spectral signatures, geomorphological, and paleoclimate modeling support the presence of mid- to low-latitude ground ice on Mars. The presence of near-surface ice and glacial features has been proposed in Ismenius Lacus, but the ice composition and age remain unconstrained. Our high-resolution stereoscopic analysis reveals distinctive landforms, including sharp-edged polyhedra, chevron patterns, and en-echelon open fractures, indicative of plastic glacial deformation. Current climatic conditions may support year-round ice stability, while sharp-edged polyhedra, open fractures, and the absence of superposed craters suggest active glaciation. The Ariguani delta system lacks fluvial signatures but aligns with glacial erosional and depositional processes. Unlike terrestrial glaciers, ice accumulation here is likely driven by escarpment-fed melt from seasonal permafrost thawing under lithostatic pressure, generating neo-glacial flows that sustain the glacial tongue. This mechanism can also explain regional features, including U-shaped valley subsidence, gravitational slides, flow of low-viscosity material lobes, and ring-mold craters. Thus, we propose sharp-edged polyhedra as diagnostic markers for identifying ongoing ice dynamics on Mars, enabling future automated detection of active glacial environments.