Odkrivanje večjih jamskih prostorov : magistrsko delo

Nemec, Matej (author), Vižintin, Goran (mentor), Bradaškja, Boštjan (comentor)

V okviru magistrske naloge je za namen odkrivanja jamskih prostorov v bližini Sežane bila uporabljena metoda georadarja. Georadar je geofizikalna metoda, ki z visoko ločljivostjo brez poseganja v kamnino zaznava različne materiale in strukture pod zemeljskim površjem in jih natančno umesti v prostor. Meritve so potekale na treh že utrjenih platojih, izmerjenih pa je bilo 31 profilov. V magistrski nalogi je predstavljenih 11 najbolj zanimivih in reprezentativnih radargramov. V teoretičnem delu naloge je predstavljeno, na kakšnem principu deluje georadar, katere so pomembnejše enačbe, zakaj se pojavlja izguba energije in dušenje, razložena je ločljivost georadarja, načini georadarskih meritev, opisani pa so tudi različni filtri, ki se uporabljajo pri postopkih obdelave podatkov in katere težave le-ti rešujejo. Predstavljena je tudi geologija krasa v Sloveniji oz. na obravnavanem območju, epikraška cona, dosedanja uporaba georadarja na krasu ter prikaz območja raziskav z okoliškimi jamami. V praktičnem delu je predstavljena oprema, s katero so potekale terenske meritve. Te so bile izvedene z RTA (Rough Terrain Antenna) 50Mhz, ki je enodelna nezaščitena antena proizvajalca Mala. V nadaljevanju je opisan postopek obdelave podatkov in filtri, ki so bili pri tem uporabljeni. Ključen aspekt, ki je bil upoštevan pri interpretaciji, so hiperbolični odboji, ki so značilni za kraške odprtine. V zaključku sledijo ugotovitve in pregled rezultatov meritev z izrisanimi poteki profilov v programu AutoCAD ter s statistiko odkritih kraških odprtin na posameznih profilih.

• Language: Slovenian
• Keywords: Georadar, jamski prostor, kras, geofizika, radargram, RTA
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: [M. Nemec]
• Year: 2023
• Number of pages: XVI, 52 str.
• PID: 20.500.12556/RUL-144714
• UDC: 550.3
• COBISS.SI-ID: 146260227
• Publication date in RUL: 09.03.2023

Secondary language

• Language: English
• Title: Discovering larger cave spaces : master's thesis

Abstract

In the thesis the method of ground-penetrating radar (GPR) was used for the purpose of discovering cave spaces near Sežana. GPR is a non-destructive geophysical method that detects different materials and structures under surface with high resolution and precisely locates them. Measurements were taken on three already hardened surfaces and 31 profiles were measured. In this thesis 11 most interesting and representative radargrams are presented. In theoretical part of the thesis the principle of how GPR is working and the most important equations are presented, it is also explained why energy loss and weakening of the signal occur. The resolution of GPR is explained, with descriptions of the different filter hats used in data processing as well as the problems which are solved with these filters. The geology of karst in Slovenia on the measured territory and the known use of the GPR on karst are presented. Besides that, the research region with neighbouring caves is shown. In the practical part the equipment used for field measurements is presented. RTA (Rough Terrain Antenna) 50Mhz, which is one-part unshielded antenna, from the Mala manufacturer was used. In continuation we describe data processing and which filters were used. The key aspect used in the interpretation are hyperbolic reflections that are characteristic of karst caves. Findings and an overview of the measurement results with drawings of directions of the profiles in the program AutoCAD are shown in the conclusion. Statistics of discovered karst caverns in individual profiles are also presented.

• Keywords: GPR, cave spaces, karst, geophysics, radargram, RTA