Thesis defence ISE - Jillian Verbeurgt

MSc Iceland School of Energy

  • 11.9.2019, 13:30 - 15:30, Háskólinn í Reykjavík

Time: September 11th at 13:30
Room: M208
Student: Jillian Verbeurgt
Thesis Title: A comparison of the surface of the geothermal systems on Reykjanes peninsula.
Supervisor(s): Haraldur Auðunsson
Associate Professor, Reykjavik University
Examiner: Magnús Tumi Guðmundsson
Professor, University of Iceland

Abstract:

Extensive aeromagnetic surveying was initiated by Þorbjörn Sigurgeirsson in 1968 (Jónsson, Kristjansson, & Sverrisson, 1991). This aeromagnetic data reveals a normally polarized band on the Reykjanes peninsula, deposited during the Brunhes chron, with reversely polarized bands on each side, deposited during the Matuyama chron. The rocks deposited during the Brunhes chron in this area contain low or negative magnetic anomalies within positively magnetized fissured swarms. These anomalies have been speculated to be due to basement formation from Matuyama, shallow structures like buried hyaloclastite formations, or high temperature activity destroying magnetite (Kristjánsson & Jónsson, 2017).

Surface magnetic data was collected for four of the geothermal systems on the peninsula, including Reykjanes, Eldvörp, Svartsengi, and Brennisteinsfjöll. This data was filtered through upward continuation to remove the noise due to surface lavas. The surface profiles were than analyzed. A comparative analysis of surface magnetic data for the geothermal systems on the Reykjanes peninsula was completed to identify similarities of the systems. These were also compared to the existing geological, aeromagnetic, and resistivity data for the area.
Simple models were created for two of the four geothermal areas to determine the contrast in magnetization due to geothermal activity. These models were based off a simple sphere where the radius was inferred based on the depth to the center of the anomaly and the depth to the top of the resistive core. The models for Svartsengi and Brennisteinsfjöll showed a decreased magnetization contrast between 2.4 and 7.5 A/m. The surface survey data for the Eldvörp area did not show a significant magnetic anomaly. Most of the surveying for Eldvörp and Reykjanes included shorth profiles that better show short wavelength anomalies. The anomalies observed in the surface magnetics were consistent with the resistivity and aeromagnetic data for each area.
There are limitations in surface magnetic surveying due to the noise incurred due to the surface lavas. Upward continuation was applied to reduce some of this noise; there is the possibility of losing meaningful data if too much noise reduction is applied. In future work, it would be useful to accommodate gridded data over the geothermal areas in interest. This way 3D analysis could be performed. This would allow for a map showing the entire lateral extent to the anomaly. A more complete picture could be gained from drill chip sampling and characterization of magnetic minerals would be useful in validating models.



Vinsamlegast athugið að á viðburðum Háskólans í Reykjavík (HR) eru teknar ljósmyndir og myndbönd sem notuð eru í markaðsstarfi HR. Hægt er að nálgast frekari upplýsingar á ru.is eða með því að senda tölvupóst á netfangið: personuvernd@ru.is

//


Please note that at events hosted at Reykjavik University (RU), photographs and videos are taken which might be used for RU marketing purposes. Read more about this on our ru.is or send an e-mail: personuvernd@ru.is