|Tipo di tesi||Tesi di laurea magistrale|
|Titolo||ORIGINE E SVILUPPO DI DEPRESSIONI CARSICHE ALL’INTERNO DEL KOTIDO CRATER, ARABIA TERRA, MARTE.|
|Titolo in inglese||ORIGIN AND DEVELOPMENT OF KARST DEPRESSIONS IN KOTIDO CRATER, ARABIA TERRA, MARS.|
|Struttura||Dipartimento di Scienze Chimiche e Geologiche|
|Corso di studi||SCIENZE E TECNOLOGIE GEOLOGICHE (D.M. 270/04)|
|Data inizio appello||2019-10-22|
|Disponibilità||Embargo di 3 anni|
|Data di rilascio||2022-10-22|
Il lavoro di tesi tratta lo studio di doline all'interno del cratere di Kotido, in Arabia Terra, Marte.
In my master thesis I have studied sinkholes within Kotido Crater, in Arabia Terra, Mars. The formation of closed depressions may be related to several genetic mechanisms acting individually or in combination: (1) differential mechanical erosion of the ground surface (e.g., deflation basins); (2) lowering of the ground by preferential surface dissolution at specific locations (e.g., solution sinkholes); (3) accumulation of deposits with an irregular top surface (e.g., moraines, landslides, dunes); (4) explosive activity (e.g., explosion craters); (5) impact of a solid body (e.g., impact craters); and (6) subsidence due to mass and/or volume depletion in the subsurface (e.g., subsidence sinkholes, thermokarst depressions, collapse calderas, sinkholes related to lava tubes, compaction/consolidation-related depressions). Four basic conditions are required for evaporite karst development: (1) the presence of soluble evaporitic sediments; (2) a supply of liquid water unsaturated with respect to the evaporitic minerals; (3) an outlet whereby the solution (or brine) can scape; and (4) a gradient causing water to flow through the system. All these conditions can be found on Mars. The Martian surface contains soluble evaporite minerals in numerous regions, as demonstrated by data gathered with instruments of several missions. A number of studies based on the analysis of high-resolution images propose the presence of karst landforms attributable to evaporite dissolution, notably sinkholes, which are widely regarded as the main diagnostic surface landform in karst areas. These geomorphic features are postulated as useful lithological indicators, and valuable markers of past paleoclimatic and paleohydrological conditions since dissolution requires the presence of liquid water. The aim of the thesis is to map some depressions present within the Kotido crater, in Arabia Terra, Mars. The work focuses mainly on the morphometric characterization and on the investigation of genetic processes and controlling factors. The morphometric parameters are derived from the analysis of satellite images provided by the High Resolution Imaging Science Experiment (HiRISE) instrument on board the NASA's Mars Reconnaissance Orbiter and by the Thermal Emission Imaging System (THEMIS) instrument on board NASA's Mars Odyssey. The data is analyzed in a GIS environment (ArcGIS 10.5.1). The preparation of the thesis was performed at the Universidad de Zaragoza, Spain.