Results 11 to 20 of about 183 (136)
Hydrogeological Characterization of Crystalline Bedrock Using Borehole Magnetic Resonance
Groundwater, Volume 61, Issue 6, Page 793-815, November/December 2023., 2023 This study is one of the first to test the applicability of the borehole magnetic resonance (BMR) method in crystalline “hard rock” environment. The aim was to investigate whether the BMR measurements could constitute an effective method for investigating detailed permeability variations in the crystalline bedrock of the two study sites: Sakatti mining
Salla Eeva +7 more
wiley +1 more source
Genesis of subglacial triangular‐shaped landforms (murtoos) formed by the Fennoscandian Ice Sheet
Earth Surface Processes and Landforms, Volume 48, Issue 11, Page 2171-2196, 15 September 2023., 2023 Murtoos are primarily depositional subglacial landforms with erosional triangular heads in the direction of the ice flow. They are produced by repeated high meltwater input and varying periodic deformation by the overriding ice. Murtoos represent a semi‐distributed drainage system under high‐pressure conditions where the rapid mobilisation of ...
Joni Mäkinen +6 more
wiley +1 more source
Geophysical Prospecting, Volume 71, Issue 7, Page 1132-1151, September 2023., 2023 Abstract Mineral exploration is facing greater challenges nowadays because of the increasing demand for raw materials and the lesser chance of finding large deposits at shallow depths. To be efficient and address new exploration challenges, high‐resolution and sensitive methods that are cost‐effective and environmentally friendly are required.
Alba Gil +7 more
wiley +1 more source
Geochemistry, Geophysics, Geosystems, Volume 24, Issue 5, May 2023., 2023 Abstract Recent studies have shown that biosignatures of ancient microbial life exist in mineral coatings in deep bedrock fractures of Precambrian cratons, but such surveys have been few and far between. Here, we report results from southwestern Sweden in an area of 1.6–1.5 Ga Paleoproterozoic rocks heavily reworked by the 1.14–0.96 Ga Sveconorwegian ...
Henrik Drake +4 more
wiley +1 more source
Journal of Geophysical Research: Solid Earth, Volume 128, Issue 4, April 2023., 2023 Abstract We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. We separate source spectra and site terms and determine intrinsic attenuation and the scattering strength of shear waves in the 3–200 Hz frequency range using radiative transfer based synthetic ...
Tom Eulenfeld +3 more
wiley +1 more source
Petrographic studies and mineralogical characterization of the Dellen impactites
Meteoritics &Planetary Science, Volume 58, Issue 4, Page 480-500, April 2023., 2023 Abstract The impact origin of the Early Cretaceous (140.82 ± 0.51 Ma) 20‐km diameter Dellen structure was proven in the late 60s based on the discovery of planar deformation features (PDFs) in quartz grains. Although decades have passed, impactites found from the crater have not received much attention. Thus, this study provides a detailed petrological
Satu Hietala +2 more
wiley +1 more source
Nonsystematic Rupture Directivity of Geothermal Energy Induced Microseismicity in Helsinki, Finland
Journal of Geophysical Research: Solid Earth, Volume 128, Issue 3, March 2023., 2023 Abstract The rupture behavior of microseismicity in fluid‐injection settings with low fault stresses is generally believed to be controlled by the pore pressure, including a tendency of the larger induced earthquakes to rupture into the perturbed volume toward the injection well, implying a degree of predictability.
J. M. Holmgren, G. Kwiatek, M. J. Werner
wiley +1 more source
Near Surface Geophysics, Volume 20, Issue 6, Page 637-660, December 2022., 2022 ABSTRACT In mineral exploration, reliable and comprehensive petrophysical groundwork helps evaluate the success rate of applying geophysical methods to the target and thus improves the quality of decision‐making related to geophysical surveys. Petrophysical data for potential field exploration can be efficiently collected from drill cores together with
Hanna Leväniemi, Janne Hokka
wiley +1 more source
Meteoritics &Planetary Science, Volume 57, Issue 11, Page 2063-2080, November 2022., 2022 Abstract The Keurusselkä structure is one of Finland's 12 meteorite impact structures—one of the world's oldest (1150 ± 10 Ma) and the largest of its kind in Finland. Findings of numerous well‐formed shatter cones in a wide area have helped define and prove Keurusselkä's impact origin.
Satu Hietala +2 more
wiley +1 more source
Geophysical Prospecting, Volume 70, Issue 1, Page 79-94, January 2022., 2022 ABSTRACT A prototype electromagnetic vibrator, referred to here as E‐Vib, was upgraded and developed for broadband hardrock and mineral exploration seismic surveys. We selected the iron oxide mine in Blötberget, central Sweden, for a test site in 2019 for the newly developed E‐Vib because of the availability of earlier seismic datasets (from 2015 to ...
Tatiana Pertuz +6 more
wiley +1 more source