izpis_h1_title_alt

Mikrogravimetrične raziskave na območju Povirja in Škocjanskih jam : magistrsko delo
ID Rupar, Lovro (Author), ID Gosar, Andrej (Mentor) More about this mentor... This link opens in a new window, ID Gabrovšek, Franci (Comentor)

.pdfPDF - Presentation file, Download (20,11 MB)
MD5: 16B92F0823018909524D215A4AA49C30

Abstract
Na območju Povirja in Škocjanskih jam sem z metodo gravimetričnega kartiranja določil težnostno anomalijo. Na območju Škocjanskih jam, kjer sta potek in oblika jam ter kanalov znana, sem izvedel meritve na 205 merskih točkah. Vplive geografske širine, nadmorske višine, topografije, plimovanja Zemlje ter hoda gravimetra sem odpravil z ustreznimi redukcijami in korekcijami. Kot primernejša za ločitev težnostnega polja se je na podlagi primerjave z modelirano težnostno anomalijo v programu IGMAS+ izkazala metoda ločitve s trendno ravnino. Karta lokalne anomalije je jasno pokazala dve večji negativni anomaliji nad Martelovo dvorano (11. največja jamska dvorana na svetu) in Šumečo jamo, prav tako je tudi nad Hankejevim kanalom manjša negativna anomalija. Amplituda negativne anomalije je nekoliko manjša od modelirane, kar je lahko posledica poenostavitve računalniškega modela, ali pa gre za posledico manjkajoče mase globlje ali plitveje od samega jamskega sistema. Na območju Povirja, kjer se zaradi iztiskanja zraka iz tal ob velikih padavinskih dogodkih predvideva obstoj večjega jamskega sistema, sem v več fazah izvedel gravimetrične meritve na 119 merskih točkah. Karta lokalne anomalije je pokazala večjo negativno anomalijo v bližini avtoceste in dve manjši anomaliji V in Z od vasi. Na območju vasi negativna anomalija ni prisotna, kar pomeni, da večjega jamskega sistema neposredno pod vasjo očitno ni, in je iztiskanje zraka verjetno povezano s sistemom razpok. Za primer večje anomalije sem modeliral težnostni odziv morebitne jame v večji globini in površinske morfološke depresije, zapolnjene s sedimenti, ki predstavlja verjetnejši vir anomalije. Zaradi izjemno sušnega leta in popolne odsotnosti padavinskih dogodkov izračuna masnih sprememb podzemne vode, ki temeljijo na kontinuiranih težnostnih meritvah, do zaključka izdelave magistrskega dela ni bilo možno izvesti, vendar se bodo meritve nadaljevale.

Language:Slovenian
Keywords:gravimetrija, Povir, Škocjanske jame, gravimetrično kartiranje, težnostna anomalija, inverzija težnostne anomalije, kontinuirane težnostne meritve
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:[L. Rupar]
Year:2022
Number of pages:XVI, 102 f.
PID:20.500.12556/RUL-140221 This link opens in a new window
UDC:55
COBISS.SI-ID:131618051 This link opens in a new window
Publication date in RUL:13.09.2022
Views:858
Downloads:210
Metadata:XML DC-XML DC-RDF
:
Copy citation
Share:Bookmark and Share

Secondary language

Language:English
Title:Microgravimetric survey in Povir and Škocjanske jame area : master's thesis
Abstract:
I have conducted a gravity survey of the Povir and Škocjanske jame area in order to determine the gravity anomaly. Measurements above the Škocjanske jame system, where the cave and conduit geometry is known, were taken on 205 points. The influence of latitude, height, topography, Earth tide an gravimeter drift were removed with appropriate corrections and reductions. Trend surface method for separation of gravity field was determined to be more suitable on the basis of comparison with the modelled anomaly in IGMAS+. Local anomaly map clearly shows two major negative anomalies above the Martelova dvorana (11th largest cave chamber in the world) and Šumeča jama, as well as a small negative anomaly above the Hankejev kanal. Measured negative anomaly is slightly lower than the modelled value, which could be a consequence of model simplification or missing mass deeper or shallower in relation to the cave system. I have also conducted multiphase gravity measurements on 119 points in the Povir area, where air blowing from beneath the ground that occurs at large rainfall events indicates the existence of a large cave system beneath the village. Local anomaly map exhibits a large negative anomaly in proximity of the highway and two smaller anomalies E and W of the village. The absence of a negative anomaly in the village centre refutes the assumption of a large cave system underneath the village, which means that the air gusts are related to a system of fissures. I have modelled the gravity response of a cave and a surface morphological depression filled with sediments, that represents the most plausible source of the anomaly. Due to extreme drought conditions and a total absence of large rainfall events the calculation of groundwater mass flux variations, that is based on continuous gravity measurements, was not implemented in the Master's thesis, but the measurements will be continued.

Keywords:gravimetry, Povir, Škocjanske jame, gravimetric mapping, gravity anomaly, gravity anomaly inversion, continuous gravity measurements

Similar documents

Similar works from RUL:
Similar works from other Slovenian collections:

Back