Teaching, research interests, thesis topics

Transcription

1 Geo2 Study track: Solid Earth Geophysics Teaching, research interests, thesis topics Geoscience Dept. Seminar

2 Teaching You ll meet me at least on these courses: Introduction to Solid Earth Geophysics Geothermics Lithosphere Structure and Dynamics Field course of Solid Earth Geophysics Borehole Geophysics

3 Research interests? Heat transfer in the Earth Deep drilling projects Applying physics in geological problems Thermal evolution of the Fennoscandian lithosphere When and how did the Fennoscandian Shield become a shield?

4 Research I m currently involved in Geothermics and geothermal energy: Deep geothermal drilling in Espoo Heat flow and heat production in Fennoscandia Heat flow and seismicity in Fennoscandia Geoneutrinos: modeling lithospheric heat production Thermal properties of rocks and nuclear waste disposal: Lab and in situ measurements of rock thermal properties in Olkiluoto Hydrothermal alteration and reflection seismic properties of rocks Petrophysics and petrology combined Low temperature thermochronology in Finland Deep boreholes in Outokumpu and Espoo

5 Thesis topics Master s thesis Solid earth geophysics

6 Deep drilling Preliminary title Notes Contact Lithology and structures of bedrock in the Otaniemi deep boreholes Geological and/or geophysical work on the samples from OTN boreholes 2 7 km (industry supported) OTN-3 (now 5385 m) OTN-2 (now 3300 m) OTN m

7 Heat transfer in rocks : Preliminary title Notes Contact Heat and mass transfer in coaxial drill hole casings for geothermal energy applications Theoretical modeling work on heat transfer (industry supported) Inverse solution of conductive heat transfer in 3D anisotropic medium Theoretical modeling related to waste disposal (industry supported)

8 Heat transfer in a coaxial borehole casing Application in geothermal energy use Down-flowing water heats up But up-flowing water cools down Optimizing flow rate, heat transfer and casing materials Numerical modeling (Comsol Multiphysics) Figures on analytical solutions adapted from Ericsson 1985

9 Reflection seismics : Preliminary title Notes Contact Processing and analysis of seismic reflection data in exploration and mining camps Seismic data processing: Several case histories available Emilia Koivisto Hydrothermally altered mineralized systems: Seismic reflection properties of rocks Experimental and theoretical study (includes both geophysics and geology) Emilia Koivisto

10 Depth (m) Hannukainen: FeOx-Cu-Au deposit Previously mined skarn /amphibolite layer with semimassive magnetite Hannukainen open pit Unknown skarn/amphibolite layers? [Adapted from Kukkonen et al., 2009]

11 Hydrothermally altered mineralized systems: Seismic reflection properties of rocks, Kevitsa Ni-Cu-PGE deposit Reflectivity depends on velocity and density Alteration: e.g., formation of secondary amphibole, epidote, serpentine, sulfides How does alteration change the reflection properties? Kevitsa: The mineralization is related to host-rock contamination (incl. alteration) Sulphides alone are not sufficient to produce reflectivity [Junno et al., 2017, under review]

12 Low temperature thermochronology: Preliminary title Notes Contact Cosmogenic isotopes in age dating of glacial bedrock morphology Initiating application of an age dating method so far not used in Finland David Whipp Seija Kultti Low temperature thermochronology: Fission track & He-U-Thmethods Studying the methods in theory and practice David Whipp Modeling of thermochronological data Thermal modeling with existing and new software David Whipp

13 Apatite fission track ages in Fennoscandia Time BP when the bedrock surface cooled below C When did the shield become a shield? Hendriks et al., 2007

14 Temperture Temperture Time Compilation of thermochronological data in Fennoscandia (Finland) Monte Carlo inversions based on track length distributions and paleotemperatures Features Cooling from orogenic events 1500 Ma Cambrian peneplain 600 Ma Early Paleozoic reheating 400 Ma Reheating at 100 Ma (?) The shield was exposed already in the Cambrian (?) New sedimentation in the Paleozoic (?) Last phase of exhumation was quite recent (< 100 Ma) (?) Murrell (2003)

15 U-Th-K geophysics and geochemistry: Radiogenic heat production Preliminary title Notes Contact Radiogenic heat production model of the lithosphere based on geochemistry and seismic data Modeling based on radiogenic heat production data and wide-angle seismic profiles in Finland Toni Veikkolainen Geoneutrinos and radiogenic heat production of the Earth Detection estimation of geoneutrinos in the Pyhäsalmi case Toni Veikkolainen

16 μw m -3 Radiogenic heat production in Finland Basic facts: HP is a primary factor controlling crustal temperatures/ HP tells the story of chemical differentiation of the earth In the map, HP was calculated from U, Th, K data on outcrops How does heat production vary with depth? How to estimate the lithospheric heat production from surface to upper mantle? Veikkolainen and Kukkonen, 2017 (in prep.)

17 Thanks for your attention! Questions? Kiitos kuulijoille!