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  • 1.
    Ahmadi, Omid
    et al.
    Department of Earth Sciences, Uppsala University.
    Juhlin, Christopher
    Department of Earth Sciences, Uppsala University, Uppsala universitet.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lund, Björn
    Department of Earth Sciences, Uppsala University.
    Revealing the deeper structure of the end-glacial Pärvie fault system in northern Sweden by seismic reflection profiling2015In: Solid Earth Discussions, ISSN 1869-9537, Vol. 6, no 2, p. 537-563Article in journal (Refereed)
    Abstract [en]

    Fault scarps that extend up to 155 km and have offsets of tens of meters at the surface are present in the northern parts of Finland, Norway and Sweden. These fault scarps are inferred to have formed during earthquakes with magnitudes up to 8 at the time of the last deglaciation. The Pärvie fault system represents the largest earthquake so far documented in northern Scandinavia, both in terms of its length and its calculated magnitude. It is also the longest known glacially induced fault in the world. Present-day microearthquakes occur along the length of the fault scarp on the eastern side of the scarp, in general agreement with an east dipping main fault. In the central section of the fault, where there is a number of subsidiary faults east of the main fault, it has been unclear how the earthquakes relate to the faults mapped at the surface. A seismic profile across the Pärvie Fault system acquired in 2007, with a mechanical hammer as a source, showed a good correlation between the surface mapped faults and moderate to steeply dipping reflectors. The most pronounced reflector could be mapped to about 3 km depth. In an attempt to map the fault system to deeper levels, a new 22 km long 2-D seismic profile which followed the 2007 line was acquired in June 2014. For deeper penetration an explosive source with a maximum charge size of 8.34 kg in 20 m deep shot holes was used. Reflectors can now be traced to deeper levels with the main 65◦ east dipping fault interpreted as a weakly reflective structure. As in the previous profile, there is a pronounced strongly reflective 60◦ west dipping structure present to the east of the main fault that can now be mapped to about 8 km depth. Extrapolations of the main and subsidiary faults converge at a depth of about 11.5 km where current earthquake activity is concentrated, suggesting their intersection has created favorable conditions for seismic stress release. Based on the present and previous seismic reflection data, potential locations for future boreholes for drilling into the fault system are proposed.

  • 2.
    Andersson, Magnus
    et al.
    Department of Earth Sciences, Uppsala University.
    Malehmir, Alireza
    Department of Earth Sciences, Uppsala University.
    Troll, Valentin R.
    Department of Earth Sciences, Uppsala University.
    Dehghannejad, Mahdieh
    Department of Earth Sciences, Uppsala University.
    Juhlin, Christopher
    Department of Earth Sciences, Uppsala University.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Carbonatite ring-complexes explained by caldera-style volcanism2013In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 3, article id 1677Article in journal (Refereed)
    Abstract [en]

    Carbonatites are rare, carbonate-rich magmatic rocks that make up a minute portion of the crust only, yet they are of great relevance for our understanding of crustal and mantle processes. Although they occur in all continents and from Archaean to present, the deeper plumbing system of carbonatite ring-complexes is usually poorly constrained. Here, we show that carbonatite ring-complexes can be explained by caldera-style volcanism. Our geophysical investigation of the Alnö carbonatite ring-complex in central Sweden identifies a solidified saucer-shaped magma chamber at ∼3 km depth that links to surface exposures through a ring fault system. Caldera subsidence during final stages of activity caused carbonatite eruptions north of the main complex, providing the crucial element to connect plutonic and eruptive features of carbonatite magmatism. The way carbonatite magmas are stored, transported and erupt at the surface is thus comparable to known emplacement styles from silicic calderas.

  • 3.
    Andersson, Magnus
    et al.
    Department of Earth Sciences, Uppsala University.
    Malehmir, Alireza
    Department of Earth Sciences, Uppsala University.
    Dehghannejad, Mahdieh
    Uppsala University, Uppsala universitet, Department of Earth Sciences, Uppsala University.
    Troll, Valentin R.
    Department of Earth Sciences, Uppsala University.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Reflection seismic and potential-field investigations of the Alnö alkaline and Carbonatite igneous complex2014In: 74th EAGE conference and exhibition incorporating SPE EUROPEC 2012: Copenhagen, Denmark, 4 - 7 June 2012, Red Hook, NY: Curran Associates, Inc., 2014, p. 5393-5395Conference paper (Refereed)
    Abstract [en]

    Alnö Island on the east coast of Sweden is well-known for its alkaline and carbonatite igneous rocks. Detailed surface geological mapping studies provide a good knowledge of the surface geology, from which geological structures and their depth extent have been inferred. The aim of this research is to constrain geological structures at depth and to improve our understanding of the intrusion mechanism(s) and the geometry of the Alnö complex as well as similar intrusions elsewhere. Three high-resolution reflection seismic profiles were acquired during 2011 across the complex. The seismic profiles suggest that the intrusion is highly reflective down to about 3 km at where the reflectivity terminates. Densely sampled surface gravity and magnetic data have also been acquired along the seismic profiles and in combination with petrophysical measurements and the seismic data will allow to construct a detailed 3D geological model of the Alnö complex.

  • 4.
    Ask, D.
    et al.
    Vattenfall Power Consultant AB, Luleå.
    Stephansson, O.
    GeoForschungsZentrum Potsdam.
    Cornet, F.H.
    Institut de Physique du Globe de Strasbourg.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Rock stress, rock stress measurements, and the Integrated Stress Determination Method (ISDM)2009In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453X, Vol. 42, no 4, p. 559-584Article in journal (Refereed)
    Abstract [en]

    The primary objectives of this work are to (1) improve the understanding of the prevailing stress distribution at the Äspö Hard Rock Laboratory (HRL) in SE Sweden by employing an integrated stress determination approach, and in order to accomplish this (2) extend the existing stress integration methodology denominated integrated stress determination method (ISDM; Cornet in Comprehensive Rock Engineering vol 3, Pergamon Press, Oxford, pp 413-432, 1993a). The new developments of the ISDM involve a 12-parameter representation of the regional stress field in the rock mass (i.e., the full stress tensor and its variation with depth) that is applicable to hydraulic stress data (sleeve fracturing, hydraulic fracturing, and hydraulic tests on pre-existing fractures), overcoring data (CSIR- and CSIRO-type of devices), and to combinations of hydraulic and overcoring stress data. For the latter case, the elastic parameters of the overcoring technique may be solved in situ by allowing the hydraulic stress data to constrain them. As a result, the problem then involves 14 model parameters. Results from the study show that the ISDM effectively improves the precision of the prevailing stress field determination and that it is especially powerful for identification of consistencies/inconsistencies in an existing data set. Indeed, this is the very basic premise and goal of stress integration; combine all available data to achieve as complete a characterization of the mechanical stress model as possible, and not to identify a solution that fits only loosely the maximum amount of stress data.

  • 5.
    Ask, Daniel
    et al.
    Vattenfall Power Consultant AB, Luleå.
    Cornet, F.H.
    Institute de Physique du Globe de Strasbourgh.
    Fontbonne, F.
    GEO-energies, Clermont-Ferrand.
    Nilsson, Tommy
    Jönsson, L.
    Hydraulikmontage i Luleå AB.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    A quadruple packer tool for conducting hydraulic stress measurements in mines and other high stress settings2009In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 46, no 6, p. 1097-1102Article in journal (Refereed)
  • 6.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Data report: consolidation state and stress ratio of clay-rich sediments from Site U13202009In: Proceedings of the Integrated Ocean Drilling Program, ISSN 1930-1014, Vol. 308Article in journal (Refereed)
    Abstract [en]

    Overpressure and fluid flow processes in the deepwater Gulf of Mexico were investigated during Expedition 308 of the Integrated Ocean Drilling Program.This data report presents the results from a reconsolidation test that was carried out on a clay-rich sample from the base of Brazos-Trinity Basin IV, at 276.40 m below seafloor. The sample was subjected to a stress path of uniaxial strain (K0 reconsolidation), and the test was conducted in an advanced triaxial cell under drained conditions. Posttest investigation revealed that the sample was disturbed by drilling. The results should be interpreted with care.The sample was loaded to a total effective vertical stress, σv′, of 24 MPa, corresponding to effective horizontal stress, σh′, of >16 MPa and vertical strain, εv, of 16%. The results propose an effective vertical yield stress of 2.03 MPa, which suggests a maximum pore fluid pressure in excess of hydrostatic water pressure of 0.24 MPa. Furthermore, the ratio between effective horizontal and vertical stresses is rather constant, ~0.7, even at high stress magnitudes.

  • 7. Ask, Maria
    In situ stress at the Cote d'Ivoire-Ghana marginal ridge from FMS logging in Hole 959D1998In: Proceedings of the Ocean Drilling Program. Scientific results, College Station, TX, 1998, p. 209-223Chapter in book (Other academic)
    Abstract [en]

    The orientation of the in situ stress between 550 and 925 meters below seafloor in Hole 959D has been derived from the analysis of caliper and electrical images of Formation MicroScanner data. Because of a high hole deviation (5°-13°), drill pipe wear has enlarged the hole in a northerly direction. As a result, the four-arm caliper analyses cannot distinguish between mechanically and stress induced borehole elongations. The FMS data show that one of the principal stresses is parallel to the borehole axis and that mainly tensile wall fractures have formed in the borehole wall. The tensile wall fractures demonstrate a 168° ± 8°N weighted mean orientation of the maximum horizontal stress. The upper 750 mbsf of the borehole comprises the majority of the tensile wall fractures, whereas they only occur sporadically below this depth. The change in the downhole distribution of fractures coincides with the transition from weaker to more compacted, stronger sedimentary rock. Furthermore, the integration of seismic and physical properties data suggests that this depth corresponds to the boundary between passive margin evolution and continent/ocean transform faulting. The orientation of the maximum horizontal stress in Hole 959D is almost perpendicular to the east-west maximum horizontal stress orientation of the first-order stress province in western and north central Africa. Through comparisons with (1) the orientations of the maximum horizontal stress in Hole 959D, (2) the maximum horizontal stress of three focal mechanisms from earthquakes in Ghana, and (3) the strike of the continental margin, it is suggested that lateral strength contrasts across the Côte d’Ivoire-Ghana Transform Margin are the most probable source for the observed stress orientations. It is further suggested that sediment loading and lateral variation in crustal thickness and density may only have a minor influence on the stress field in this area.

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  • 8. Ask, Maria
    In situ stress from borehole breakouts in Denmark1996Licentiate thesis, comprehensive summary (Other academic)
  • 9. Ask, Maria
    In-situ and laboratory stress investigations using borehole data from the North Atlantic Ocean1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis presents results from investigations ofin-situ and laboratory stress from borehole logging andlaboratory deformation experiments on drill-cores. The datacome from hydrocarbon exploration and production wells in theDanish Sector of the North Sea, and from boreholes drilled bythe Ocean Drilling Program (ODP). The drill-core samples werecollected from two ODP boreholes in the equatorial and easternAtlantic Ocean. The objectives for this project are: (1) to collect datafrom the North Atlantic Ocean where few or no stressmeasurements exist, and to incorporate the data into the WorldStress Map (WSM); (2) to determine the source of stress thatgenerates the mean orientation of the maximum horizontal stressin individual boreholes in ocean areas; and (3) to study themechanical responses of sediments and rocks in order tounderstand the nature of stress and stress paths that producedeformation of the ocean floor. The orientations of in-situ horizontal stresses weredetermined from analyses of borehole breakouts anddrilling-induced fractures (DIFs) as determined from four-armcaliper and Formation MicroScanner (FMS) data. Logging datawere analyzed using graphical and automated programs, usingbreakout and DIF criteria, directional statistics, and theborehole data were ranked according the WSM ranking system. Stress data from 44 oil wells and ODP boreholes in the NorthAtlantic Ocean represent important additions to the WSM fromareas where few stress data were available. Despite of theirrelatively shallow total depths, it is suggested that thestress orientation in many of the ODP boreholes are influencedby plate boundary forces. The observed variation in downholedistribution of breakouts in the oil wells and the lack ofregional trends indicate that local and regional stress sourcescontrol the stress field in these wells. Detailed laboratory stress measurements were conducted in atriaxial cell mounted in a servo-hydraulic load frame, usingreconsolidation and triaxial tests on small sub-samples fromtwo drill-core samples of different lithologies. Results from tests on a claystone from the basal section ofthe ocean-continent transition in West Iberia margin suggestthat the in-situ effective stresses are low because of the highpore pressure. The fractured nature of the underlying basementand breccia suggest that the pore fluids originate from deepersections. Results from tests on a calcarenite from about 1 kmdepth show that the elastic versus elastic-plastic behaviordiffers significantly, but that the rock behavior can bedescribed by critical state soil mechanics.

  • 10. Ask, Maria
    In-situ stress from breakouts in the Danish sector of the North Sea1997In: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 14, no 3, p. 231-243Article in journal (Refereed)
    Abstract [en]

    Borehole breakouts from 26 wells situated in the Danish Central Graben and one well situated in the northwestern section of the Ringkobing-Fyn High have been studied. The data provide information on the orientation of the contemporary principal horizontal stresses down to depths of 4.7 km. Statistics were used to obtain a mean azimuth of breakouts for each well, and each individual breakout was weighted by its length. Data quality of breakouts is assigned according to the World Stress Map quality ranking scheme. The breakout data reveal that SH orientations in the Danish Central Graben are extremely scattered; no regional trend in mean SH orientation can be identified as a result of the large standard deviation (±77°). Similar scatterings of SH orientations have been reported from adjacent regions of the North Sea. The results indicate that the state of stress in the sedimentary cover of the Danish Central Graben is influenced by a local stress generating mechanism rather than platewide stress transmissions mechanisms. Three units with different states of stress have been identified and found to correspond somewhat with the lithostratigraphic divisions of the Post Chalk Group, Chalk Group and Pre Chalk Group.

  • 11. Ask, Maria
    Mechanical tests on claystone from Ocean Drilling Program Hole 1070A (Leg 173): implications for elevatedpore-fluid pressure in sediments within the ocean-continent transition zone, West Iberia2001In: Marine Geology, ISSN 0025-3227, E-ISSN 1872-6151, Vol. 177, no 3, p. 395-410Article in journal (Refereed)
    Abstract [en]

    Laboratory geotechnical deformation tests on a claystone test specimen from 619 m depth in Ocean Drilling Program Hole 1070A provide evidence of low effective yield stresses and capillary pressures (1.2–1.5 MPa) in the sediment section near the acoustic basement. Effects from negative pore-fluid pressure, and the presence of expansive clay minerals probably account for the drastic change in the mechanical behavior of the sample below and above the yield stress. The results from the geotechnical tests, together with high porosity values, suggest that the pore-fluid pressure is high in these basal sediments. The intense fracture/vein development in the basement suggests that the pore-fluids originate from deeper sections in the basement. Porosity anomalies are found near the basement in three boreholes drilled in the western part of the Iberia Margin. The anomalies are interpreted to signal elevated pore-fluid pressure. Consequently, a zone of overpressure possibly exists in the western part of the ocean-transition zone of the West Iberia margin, which thickens towards the west.

  • 12.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Project: Assessing the state of in-situ stress, deformation properties and consolidation processes in marine clay-rich sediments at the Nankai accretionary prism2010Other (Other (popular science, discussion, etc.))
    Abstract [en]

    Some of Earth's largest earthquakes occur along décollement faults that separate overriding plate and accretionary prism from subducting plate. I conduct a collaborative experimental study to assess in-situ stress state, deformation properties, and consolidation processes in clay-rich sediments from the Nankai accretionary prism (NAP), SE Japan. Some of these sediments will ultimately pass into the seismogenic zone where earthquakes are generated.

  • 13.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Technological Drivers for Future IODP Science: Progressing from application-specific to systematic technological development2009Conference paper (Refereed)
    Abstract [en]

    Since its inception with the Deep Sea Drilling Project (DSDP) scientific ocean drilling has always had a technology development component. Technology development has been critical for advancing ocean drilling and scientific progress would not have occurred without it. Resolution of the simpler technical problems have progressed satisfactorily through an application-specific process, however the more difficult and complex problems that limit achieving many of the scientific objectives of the Initial Science Plan (ISP) and active IODP drilling proposals remain unresolved and will require a more comprehensive and systematic effort. This White Paper highlights key technological/scientific goals identified by the Engineering Development Panel (EDP)-Improving Core Recovery and Quality; Addressing Geohazards; Microbiology in the Marine Subsurface Environment; Drilling to the Moho and Other Complex Drilling Projects; and Virtual Staffing-that are derived from the EDP Technology Roadmap v. 3.0 (http://www.iodp.org/eng-dev), the ISP, and active drilling proposals; and reinforced by the Science and Technology Panel (STP) Roadmap (v. 0.93). They offer the greatest promise for transforming scientific ocean drilling. In order to accomplish some of these goals, large-scale engineering developments will be necessary to deliver the transformational science needed by any drilling program beyond 2013.

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    FULLTEXT01
  • 14.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Abdujabbar, Mawaheb
    Luleå tekniska universitet.
    Lund, Björn
    Department of Earth Sciences, Uppsala University, Institutionen för geovetenskaper, Uppsala Universitet.
    Smith, Colby A.
    Sveriges Geologiska Undersökning, Geological Survey of Sweden.
    Mikko, Henrik
    Sveriges Geologiska Undersökning, Geological Survey of Sweden.
    Munier, Raymond
    Svensk Kärnbränslehantering AB, Swedish Nuclear Fuel and Waste Management Company (SKB).
    Geomorphology of intraplate postglacial faults in Sweden2015Conference paper (Other academic)
    Abstract [en]

    Melting of the Weichselian ice sheet at ≈10 000 BP is inferred to have induced large to great intraplate earthquakes in northern Fennoscandia. Over a dozen large so-called postglacial faults (PGF) have been found, mainly using aerial photogrammetry, trenching, and recognition of numerous paleolandslides in the vicinity of the faults (e.g. Lagerbäck & Sundh 2008). Recent LiDAR-based mapping led to the extension of known PGFs, the discovery of new segments of existing PGFs, and a number of new suspected PGFs (Smith et al. 2014; Mikko et al. 2015). The PGFs in Fennoscandia occur within 14-25°E and 61-69°N; the majority are within Swedish territory. PGFs generally are prominent features, up to 155 km in length and 30 m maximum surface offset. The most intense microseismic activity in Sweden occurs near PGFs. The seismogenic zone of the longest known PGF (Pärvie fault zone, PFZ) extends to ≈40 km depth. From fault geometry and earthquake scaling relations, the paleomagnitude of PFZ is estimated to 8.0±0.3 (Lindblom et al. 2015). The new high-resolution LiDAR-derived elevation model of Sweden offers an unprecedented opportunity to constrain the surface geometry of the PGFs. The objective is to reach more detailed knowledge of the surface offset across their scarps. This distribution provides a one-dimensional view of the slip distribution during the inferred paleorupture. The second objective is to analyze the pattern of vertical displacement of the hanging wall, to obtain a two-dimensional view of the displaced area that is linked to the fault geometry at depth. The anticipated results will further constrain the paleomagnitude of PGFs and will be incorporated into future modeling efforts to investigate the nature of PGFs.

  • 15.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Daniel
    Sverige.
    Project: Detection of potential borehole breakouts in boreholes2010Other (Other (popular science, discussion, etc.))
    Abstract [en]

    This project investigates the occurrence of stress-induced borehole breakouts in two boreholes at the Forsmark site, KFM01A and KFM01B, that are 500 and 1000 m deep, respectively. The primary objective was to investigate if borehole breakouts are formed in Forsmark. The results confirm the occurrence of stress-induced features, and borehole boreholes were detected between 116 and 997 m vertical depth (mvd) in the two boreholes.

  • 16.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Ask, Daniel
    Vattenfall Power Consultant AB, Luleå.
    Christiansson, R.
    Swedish Nuclear Fuel and Waste Management Co.
    Detection of borehole breakouts at the Forsmark site, Sweden2006In: In-situ rock stress: measurement, interpretation and application : proceedings of the International Symposium on In-situ Rock Stress, Trondheim, Norway, June 19-21, 2006/ / [ed] Ming Lu, London: Taylor and Francis Group , 2006, p. 79-86Conference paper (Refereed)
    Abstract [en]

    The objective of this paper was to investigate if borehole breakouts exist at the Forsmark investigation site of the Swedish Nuclear Fuel and Waste Management Co. Breakouts generally form when the stress concentration around the borehole exceeds the rock strength of the borehole wall, and result in borehole failure in the direction parallel to the minimum horizontal stress in vertical boreholes. Borehole televiewer and borehole image processing system data in boreholes KFM01A and KFM01B have been analyzed. The analyzes reveal that breakouts appear over 30-40% of the length of the investigated boreholes. The breakouts appear with both shallow- and deep-failure depths, where the overwhelming majority is of the shallow failure type. The scope of this initial study does not include the full characterization of identified breakouts and it is not clear at this stage as to the origin of the breakouts, i.e. if they are stress and/or drilling induced

  • 17.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. FracSinus Rock Stress Measurement AB, Luleå.
    Cornet, Francois
    University of Strasbourg, School and Observatory of Earth Sciences, Strasbour.
    Nilsson, Tommy
    University of Strasbourg, School and Observatory of Earth Sciences, Strasbourg.
    A hydraulic stress measurement system for deep borehole investigations2017In: Geophysical Research Abstracts, ISSN 1029-7006, E-ISSN 1607-7962, Vol. 19Article in journal (Refereed)
    Abstract [en]

    Lulea University of Technology (LTU) is developing and building a wire-line system for hydraulic rock stress measurements, with funding from the Swedish Research Council and Lulea University of Technology. In this project, LTU is collaborating with University of Strasbourg and Geosigma AB. The stress state influences drilling and drillability, as well as rock mass stability and permeability. Therefore, knowledge about the state of in-situ stress (stress magnitudes, and orientations) and its spatial variation with depth is essential for many underground rock engineering projects, for example for underground storage of hazardous material (e.g. nuclear waste, carbon dioxide), deep geothermal exploration, and underground infrastructure (e.g. tunneling, hydropower dams). The system is designed to conduct hydraulic stress testing in slim boreholes. There are three types of test methods: (1) hydraulic fracturing, (2) sleeve fracturing and (3) hydraulic testing of pre-existing fractures. These are robust methods for determining in situ stresses from boreholes. Integration of the three methods allows determination of the three-dimensional stress tensor and its spatial variation with depth in a scientific unambiguously way. The stress system is composed of a downhole and a surface unit. The downhole unit consists of hydraulic fracturing equipment (straddle packers and downhole imaging tool) and their associated data acquisition systems. The testing system is state of the art in several aspects including: (1) Large depth range (3 km), (2) Ability to test three borehole dimensions (N=76 mm, H=96 mm, and P=122 mm), (3) Resistivity imager maps the orientation of tested fracture; (4) Highly stiff and resistive to corrosion downhole testing equipment; and (5) Very detailed control on the injection flow rate and cumulative volume is obtained by a hydraulic injection pump with variable piston rate, and a highly sensitive flow-meter. At EGU General Assembly 2017, we would like to present this new and unique stress measurement system and some initial test results from a 1200 m long borehole in crystalline rock

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  • 18.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Daniel
    GEOSIGMA, Uppsala.
    Elvebakk, Harald
    Norges Geologiske Undersøkelse.
    Olesen, Odleiv
    Norges Geologiske Undersøkelse.
    Stress Analysis in Boreholes Drag Bh and Leknes Bh, Nordland, North Norway2015In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453X, Vol. 48, no 4, p. 1475-1484Article in journal (Refereed)
    Abstract [en]

    Nordland in northern Norway is characterized by enhanced seismicity and uplift that makes it the most tectonically active area in Norway. This study is part of a project entitled Neotectonics in Norway—Implications for Petroleum Exploration, which aims at enhancing the understanding of regional-scale stress and strain dynamics in Nordland, and to impact risk and hazard assessment and petroleum exploration. This paper attempts to constrain the orientation of in situ horizontal stress using high-resolution acoustic televiewer logging data. The Geological Survey of Norway has drilled two 0.8 km deep near-vertical boreholes on opposite sides of the Vestfjord in Nordland, the open bight of sea that separates the Lofoten archipelago from the Norwegian mainland. Both boreholes are drilled just North of 68_ N, with borehole Leknes Bh located near the geographic center of the Lofoten archipelago, and borehole Drag Bh located on approximate equal distance from the shore, on the Norwegian mainland. The results of this study are in most practical aspects inconclusive, mainly due to poor data quality. The data analysis has revealed erroneously high-borehole diameter, and several artifacts such as eccentric logging tool, rugose borehole wall, spiral hole, tool sticking and missing data. Four intervals with passive in situ stress indicators (borehole breakout and drilling-induced fractures) were found in travel time and amplitude images of the Drag Bh, suggesting approximately N–S orientation of maximum horizontal stress. However, these intervals are not found in cross-plots. Either result yields the lowest World Stress Map ranking quality (E).

  • 19.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rosberg, Jan Erik
    Lund University.
    Exploration for deep enhanced geothermal systems with Riksriggen and the LTU downhole stress measurement system2017In: 4th Sustainable Earth Sciences Conference and Exhibition 2017, Held at Near Surface Geoscience Conference and Exhibition 2017, European Association of Geoscientists and Engineers, 2017, p. 21-25Conference paper (Refereed)
    Abstract [en]

    Recent developments in drilling technology have resulted in about five to ten times faster penetration rates compared to penetration rates of conventional diamond drilling. The increased penetration rates open up for affordable drilling of deep boreholes in regions with cold crust, such as in Scandinavia, allowing for geothermal energy generation in enhanced geothermal systems. We present two infrastructures for downhole sampling and testing, Riksriggen and the LTU downhole stress measurement system. Riksriggen produces a borehole that allows in-situ sampling and testing to 2.5 km depth. Furthermore, highly relevant data for geothermal energy production is produced, for example fracture geometries and frequencies, as well as depth of zones with elevated transmissivity zones and their in-situ hydraulic conductivities. The LTU downhole stress measurement system allows determination of the three-dimensional stress tensor and its spatial variation with depth in a scientific unambiguously way. Thus, Riksriggen and the LTU downhole stress measurement system provide data needed for planning most stable borehole trajectory with depth and to determine optimal pattern of production and injection wells (e.g. hydraulic stimulation by fraccing), as well as for assessing the risk of induced seismicity.

  • 20. Ask, Maria
    et al.
    Beslier, Marie-Odile
    Boillot, Gilbert
    Ocean-continent boundary in the Iberia Abyssal Plain from multichannel seismic data1993In: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 218, no 4, p. 383-393Article in journal (Refereed)
    Abstract [en]

    The Ocean-Continent Boundary of the West Iberia margin is marked by a basement ridge trending N-S. Four segments of this ridge are recognized, each of them being progressively offset westward from 40°N to 43°N. Because the setting and seismic character of the ridge in the Iberia Abyssal Plain are similar to those of the Galicia margin ridge, which is made of serpentinized peridotite, we think that the southern segments of the ridge are also made of the same mantle material. The segmentation of the ridge suggests that the northward propagation of the continental break-up during the North Atlantic opening in Early Cretaceous times was discontinuous, each segment possibly corresponding to a propagation step. East of the ridge, the basement of the whole Iberia Abyssal Plain consists of highly thinned continental crust locally resting on a seismic reflector that resembles the S reflector previously recognized off Galicia. By analogy with the Galicia margin, we propose that the tilted crustal blocks lay on serpentinized peridotite derived from the upper mantle, the S reflector corresponding to the contact between crustal rocks and serpentinite.

  • 21.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bruckman, ViktorAustrian Academy of Sciences.Juhlin, ChristopherDepartment of Earth Sciences, Uppsala University.Kempka, ThomasGFZ German Research Centre for Geoscience.Kühn, MichaelGFZ German Research Centre for Geoscience.
    European Geosciences Union General Assembly 2016: EGU Division Energy, Resources & the Environment (ERE)2016Conference proceedings (editor) (Refereed)
    Abstract [en]

    The EGU General Assembly 2016 was held under the conference theme “Active Planet” from 16-22 April 2016 in Vienna, Austria. The program consisted of 619 unique scientific sessions and 321 side events. A total of 16,300 contributions were presented in the form of posters (64%), oral presentations (30%) and interactive content (PICO, 6%). The 13,650 participants originate from 109 countries, of which the majority were early career scientists (53%) and students (25%). Over the last decade, EGU has expanded in terms of number of scientific contributions (62% increase) and number of participants (57% increase).

    The scientific program of the Division Energy, Resources & the Environment (ERE) was organized around six main groups of sessions: (1) integrated studies, (2) impact of energy and resource exploitation on the environment, (3) non-carbon based energy, (4) carbon based energy, (5) geo-storage for a sustainable future, and (6) geo-materials from natural resources. The division hosted 19 sessions and co-organized further 13 with others. In total, 458 presentations came from ERE, corresponding to almost 3% of all contributions of the EGU General Assembly 2016.

    This special issue presents some of the current and coming applied research topics within the fields of energy, resources and the environment, and also documents the ERE activities at the recent EGU General Assembly. Below, a brief description of the scientific program [1] is given, sorted with respect to the six main groups of sessions. Comparable overview issues were published in Energy Procedia in previous years [2-4].

  • 22.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hangx, SuzanneDepartment of Earth Sciences, Utrecht University.Bruckman, ViktorAustrian Academy of Sciences, Commission for Interdisciplinary Ecological Studies, Austrian Academy of Sciences, Section for Mathematics and Natural Sciences.Kühn, MichaelGFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam.
    European Geosciences Union General Assembly 2015: Division Energy, Resources and Environment, EGU 20152015Collection (editor) (Refereed)
    Abstract [en]

    The European Geosciences Union brings together geoscientists from all over Europe and the rest of the world, covering all disciplines of the earth sciences. This geoscientific inter- and multi- disciplinarity is needed to tackle the challenges of the future. A major challenge for humankind is to provide adequate and reliable supplies of affordable energy and other resources. These should be obtained in environmentally sustainable ways, which is essential for economic prosperity, environmental quality and political stability around the world. This issue gives a general overview of contributions during the General Assembly 2015 in the division for Energy, Resources & the Environment.

  • 23. Ask, Maria
    et al.
    Janik, A.G
    Hood, J.A.
    Physical properties data at Hole 959D: comparison of core and log measurements and a proposed revision of lithologic units1998Conference paper (Other academic)
    Abstract [en]

    A revised division of lithologic units is proposed for Hole 959D in the interval from 400 to 1000 meters below seafloor from Ocean Drilling Program Leg 159 based on combining the geophysical and sedimentological information. This new division is essential for further geological studies of the Cote d’Ivoire-Ghana Transform Margin area. A comparison is made between shipboard laboratory measurements made on core samples and in situ downhole logging data. Logging data, in conjunction with physical properties data, provide a more detailed record of the variation in the sediment column, which enables a more qualitative assessment of lithotype distribution. Emphasis is placed on distinguishing between the lithologic factors influencing the geophysical signals and artifacts resulting from imperfect data collection. Good overall agreement between core and log data for rotary core barrel cored sediments at Hole 959D is observed, and effects of core expansion caused by the removal of overburden pressure do not appear significant.

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  • 24.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Kopf, Achim
    DFG Research Center Ocean Margins, University of Bremen.
    Constraints on the state of in situ effective stress and the mechanical behavior of ODP Leg 186 claystones in the Japan Trench forearc2004In: Island Arc, ISSN 1038-4871, E-ISSN 1440-1738, Vol. 13, no 1, p. 242-257Article in journal (Refereed)
    Abstract [en]

    The Japan Trench forearc offshore Honshu Island in northeast Japan, where the 130-m.y.-old Pacific oceanic plate is presently subducted, was drilled during the Ocean Drilling Program Leg 186. Results from mechanical and sedimentological studies of claystones recovered from Sites 1150 and 1151 in the overlying erosional forearc wedge are reported in the present study. Although many physical properties are similar in the seismic (Site 1150) and aseismic portion (Site 1151) of the shallow forearc, Site 1150 displayed a higher abundance of open fractures, two prominent fault zones and enigmatic pore fluid signatures in the claystones. The abundance of weak mineral phases, together with high smectite contents (from X-ray diffraction), control the low friction coefficients of 0.33–0.39 of the claystones in ring-shear experiments. Results from triaxial testing proposed overall low magnitudes of in situ effective vertical stress, with somewhat lower values at Site 1150 than at Site 1151. Similarly, samples from Site 1150 displayed slightly higher pore fluid pressures than those at Site 1151. The high sediment porosities, which are in part also a result of intact diatom tests (from scanning electron microscope), together with the anomalous fluid signatures and elevated pore fluid pressures, could very likely result from upward migration and influx of deep-seated waters. Dewatering reactions at depth result in enhanced pore fluid pressure transients along out-of-sequence thrusts and consequently lower effective stress. At depths greater than that of Leg 186 drilling, elevated pressure–temperature conditions trigger mineral transformation and cementation, which result in increasing friction, unstable sliding and seismic rupture. Such earthquakes could have repeatedly disaggregated the consolidated claystone fabrics at the seismic site, and could be responsible for differences in yield strength and cementation when compared to the aseismic Site 1151.

  • 25. Ask, Maria
    et al.
    Leonard, J.N.
    Water content variations in lower trench slope sediment of Vanuatu, Nankai Trough, and Barbados Ridge: comparison of results from ODP Legs 110, 131, and 1341994In: Proceedings of the Ocean Drilling Program. Scientific results, College Station, TX, 1994, p. 531-547Chapter in book (Other academic)
  • 26.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Morgan, Julia
    Rice University.
    Projection of mechanical properties from shallow to greater depths2008Conference paper (Other academic)
    Abstract [en]

    Deformation processes in sediments are directly controlled by the state of in situ effective stresses, the mechanical-, physical- and geochemical properties of the materials of the fault zone and surrounding wall rocks, and time. Measurements of these properties are needed for understanding of the process of earthquake generation. The recent drilling expeditions to Nankai Trough, by the Integrated Ocean Drilling Program demonstrate the technical difficulties involved in subduction zone drilling. At present, scientific drilling operations have successfully penetrated the decollement only at shallow depths in the Nankai accretionary prism. These data provide the only present access to future seismogenic zone materials. In the frontal region, the strata are being partitioned into accreting and subducting packages, some of which may ultimately pass into the seismogenic zone. Sediments deposited and locally cemented within the Shikoku Basin are partitioned by the basal decollement and they follow distinctive deformation pathways across the margin. Our hypothesis is that enhanced strength in the underthrust package allows it to carry excess pore fluids deep into the subduction zone, potentially to be released rapidly and seismogenically. The objectives for mechanical testing are to probe the yield and failure surfaces of these sediments, as well as their post-failure deformation behavior. This information is useful for making predictions about sediment response to accretion, underplating, and slip along the decollement. Reconsolidation tests have been carried out on Ocean Drilling Program cores collected from the reference site seaward of the active Nankai decollement zone off the southeast coast of Japan (ODP Site 1173). We have conducted two tests each from two subsamples from within Lower Shikoku Basin, approximately 30 m above, and approximately 85 m below the proto-decollement. This allows documentation of changes in mechanical strength and stress history across the proto-decollement horizon within the same lithostratigraphic unit. The initial porosities for the deeper and shallower samples are 43-44% and 56-57%, respectively. The results suggest that the shallower samples are significantly stiffer than the deeper ones, which is reflected by higher effective yield stress and higher elastic modulus in the shallower samples. The results regarding the elastic-plastic behavior is more challenging to interpret: One sample from above the decollement experienced brittle failure at an effective vertical stress of 8.7 MPa, whereas one sample from below the decollement show evidence on cement destruction and plastic deformation up to the maximum stress of 9.5 MPa. These two stress levels also are the highest effective vertical stress of samples. The results will contribute to our model for the evolution of deformation in sediments in the Nankai accretionary prism They will also allow us to project the mechanical behavior from shallow to greater depths.

  • 27.
    Ask, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Morgan, Julia K.
    Rice University, Houston.
    Projection of mechanical properties from shallow to greater depths seaward of the Nankai accretionary prism2010In: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 482, no 1-4, p. 50-64Article in journal (Refereed)
    Abstract [en]

    Deformation processes in sediments at accretionary prisms are directly controlled by the state of in situ effective stresses, the mechanical, physical and geochemical properties of the materials of the fault zone and surrounding wall rocks, as well as time. Measurements of these properties and their evolution in space and time, are therefore needed for a full understanding of the process of earthquake generation within subduction zones.Reconsolidation tests have been carried out on Ocean Drilling Program cores collected from a reference site seaward of the active Nankai décollement zone off the southeast coast of Japan. The reconsolidation stress path subjects the samples to uniaxial strain deformation, which mimics their stress history, however at much higher loading rates than in the natural system. We have conducted two tests each from two mudstone samples within Lower Shikoku Basin. The samples were collected at 361 and 476 meter below seafloor, on either side of the protodécollement horizon.The objectives for mechanical testing are to probe the yield and failure surfaces of these shallow sediments (Considering their large scale behavior, our tests show that the samples collected above the protodécollement have higher strength than those below. We propose that cementation, microfabric and mineralogy of the sediments above the protodécollement result in a higher effective yield stress than predicted from in situ effective vertical stress at hydrostatic pore pressures. Sediments below the protodécollement, in contrast, are slightly underconsolidated, and provide an upper constraint on the magnitude of in situ effective vertical stress and pore-fluid pressure. We also used the test results to make initial predictions for the yield surface in 2D and 3D for subdécollement samples across the margin. The construction of the 2D yield surface is the first attempt to quantify the model of sediment deformation proposed by Morgan et al. (2007). These results hint that the presence of cement has a strong, and increasing, influence on sediment behavior. Further testing is needed to verify these findings.

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  • 28. Ask, Maria
    et al.
    Müller, B.
    Stephansson, Ove
    In-situ stress determination from breakouts in the Tornquist Fan, Denmark1996In: Terra Nova, ISSN 0954-4879, E-ISSN 1365-3121, Vol. 8, no 6, p. 575-584Article in journal (Refereed)
    Abstract [en]

    The Tornquist Fan, a fan-shaped region in Denmark and Western Baltic, is situated in the transition zone between the Western and Northern European Stress Provinces. Breakout data from 20 wells (0.3-3.6 km) were analysed. The fan can be divided into three stress provinces: (i) The area south of the Romo Fracture Zone is part of the Western European Stress Province and has NNW-SSE orientation of the maximum horizontal stress, (ii) The sediment cover in the Norwegian-Danish Basin is dominated by ENE-WSW orientated maximum horizontal stress, (iii) The maximum horizontal stress is sub-parallel to the strike of the Sorgenfrei-Tornquist Zone. Deviations from the regional stress field were observed in wells close to faults and salt diapirs. In wells south of the Sorgenfrei-Tornquist Zone, breakout occurrence decreases with increasing age of the stratigraphic units. The downhole breakout distribution seems to correlate with lithology and thickness of the sediment layer.

  • 29. Ask, Maria
    et al.
    Stephansson, Ove
    Prediction of stress orientation and distribution in Denmark based on borehole breakout data from the Tornquist Fan and the Danish Central Graben1996In: Prediction and performance in rock mechanics and rock engineering: proceedings ; ISRM international symposium, Torino, Italy, 1996.09.2-5 / [ed] Giovanni Barla, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1996, p. 411-418Conference paper (Refereed)
  • 30.
    Auchar Zardari, Muhammad
    et al.
    Quaid-e-Awam University of Engineering Science and Technology: Nawabshah, Pakistan.
    Mattsson, Hans
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Khalid, Muhammad S.
    Department of Urban Management, Kyoto University, Kyoto, Japan.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lund, Björn
    Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam2017In: Advances in Materials Science and Engineering, ISSN 1687-8434, E-ISSN 1687-8442, Vol. 2017, article id 5389308Article in journal (Refereed)
    Abstract [en]

    Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes

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  • 31. Bondarchuk, Alexander
    et al.
    Ask, Maria
    Dahlström, Lars-Olof
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Numerical analysis of rock mass behavior under hydropower embankment dams2009In: Föredrag vid Bergmekanikdag i Stockholm 9 mars 2009, Stiftelsen bergteknisk forskning - Befo , 2009, p. 149-158Conference paper (Other academic)
    Abstract [sv]

    Numeriska analyser av bergmassans beteende under fyllningsdammar för vattenkraftproduktion

  • 32.
    Bondarchuk, Alexander
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Rock mass behavior under hydropower embankment dams: a two-dimensional numerical study2012In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453X, Vol. 45, no 5, p. 819-835Article in journal (Refereed)
    Abstract [en]

    Sweden has more than 190 large hydropower dams, of which about 50 are pure embankment dams and over 100 are concrete/embankment dams. This paper presents results from conceptual analyses of the response of typical Swedish rock mass to the construction of a hydropower embankment dam and its first stages of operation. The aim is to identify locations and magnitudes of displacements that are occurring in the rock foundation and grout curtain after construction of the dam, the first filling of its water reservoir, and after one seasonal variation of the water table. Coupled hydro-mechanical analysis was conducted using the two-dimensional distinct element program UDEC. Series of the simulations have been performed and the results show that the first filling of the reservoir and variation of water table induce largest magnitudes of displacement, with the greatest values obtained from the two models with high differential horizontal stresses and smallest spacing of sub-vertical fractures. These results may help identifying the condition of the dam foundation and contribute to the development of proper maintenance measures, which guarantee the safety and functionality of the dam. Additionally, newly developed dams may use these results for the estimation of the possible response of the rock foundation to the construction

  • 33. Bondarchuk, Alexander
    et al.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Dahlström, Lars-Olof
    Nordlund, Erling
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Hydromechanical numerical analysis of rock mass behavior under a Swedish embankment hydropower dam2009In: Long Term Behaviour of Dams: Proceedings of the 2nd International Conference, 12th-13th October 2009, Graz, Austria / [ed] Erich Bauer; Stephan Semprich; Gerald Zenz, Graz: Verl. der Techn. Univ. Graz , 2009, p. 113-118Conference paper (Refereed)
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  • 34.
    Bruckman, Viktor
    et al.
    Austrian Academy of Sciences, Section for Mathematics and Natural Sciences.
    Hangx, SuzanneDepartment of Earth Sciences, Utrecht University.Ask, MariaLuleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    European Geosciences Union General Assembly 2014, EGU Division Energy, Resources & the Environment (ERE)2014Collection (editor) (Refereed)
  • 35.
    Camerlenghi, A.
    et al.
    University of Barcelona.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Dugan, B.
    Rice University, Houston.
    Kopf, A.
    MARUM, Bremen.
    Morgan, J.
    Rice University, Houston.
    Suyehiro, K.
    JAMSTEC.
    Urgeles, R.
    University of Barcelona.
    Good reasons for IODP to address submarine geohazards: (with focus on the Mediterranean)2009Conference paper (Refereed)
    Abstract [en]

    Following a number of international workshop held in the last few years, this documents synthesise the reasons why future scientific ocean drilling should prioritize geohazards among the scientific objectives. In essence the reasons are the societal relevance, the opportunity to deepen the knowledge of basic geological processes in basin evolution, and the opportunity for technological development. A focus in placed on the Mediterranean Basin because of its high vulnerability to submarine geohazards, and to the known widespread occurrence (in the present and in the recent geological record) of geohazards. Among geohazards of the Mediterranean, a focus is placed on the submarine landslides because of their potential to affect seabed structure and the coastline via the tsunamis they can generate. A list of technological needs and a list of the international workshops is added for reference at the end of the document.

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  • 36.
    Elhami, Ehsan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Erlström, Mikael
    Geological Survey of Sweden.
    Mattsson, Hans
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Physical Properties of Core Samples from the Swedish Part of the Southern Baltic Sea: Implications for CO2 Storage2016In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 97, p. 356-363Article in journal (Refereed)
    Abstract [en]

    This paper presents the results from a series of physical measurements conducted on core samples from the Swedish part of the southern Baltic Sea. The samples consist of 16 Cambrian sandstone samples (potential reservoir rock) and 9 Ordovician limestone samples (potential caprock). The two rock types reveal contrasting properties; axial P-wave velocity and density for the sandstone samples are 3.14±0.95km/s and 2.26±0.12 gr/cm3, respectively while for the limestone samples they are 6.09±0.22km/s and 2.58±0.08 gr/cm3, respectively. The scatter of the evaluated properties indicates aleatory variability and epistemic uncertainty in the properties which can be better addressed by further tests on more samples.

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  • 37.
    Elhami, Ehsan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mattsson, Hans
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Physical- and geomechanical properties of a drill core sample from 1.6 km depth at the Heletz site in Israel: Some implications for reservoir rock and CO2 storage2016In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 48, no 1, p. 84-93Article in journal (Refereed)
    Abstract [en]

    We have measured physical- and geomechanical properties of a core sample that was collected from 1.6 km depth at the Heletz site in Israel, within reservoir rock, layer A. The core sample is composed of poorly consolidated sandstone, with several layers of coarser grain sizes. Average bulk density and porosity are 1.93 ± 0.11 g/cm3 and 36 ± 5%, respectively.Both nondestructive and destructive tests have been made on the core sample and its subsamples, including CT-scanning, oedometer tests, drained direct shear tests, as well as measurements of index properties, X-ray fluorescence and X-ray diffraction. These tests provide an initial evaluation of the properties of the reservoir rock, but are far from capturing epistemic variability of the reservoir rock. The results support the macroscopic observation, that the sample is poorly consolidated compared to its depth of deposition. The effective pre-consolidation pressure is less than 0.2 MPa and the maximum peak shear strength obtained is less than 1 MPa (normal stress = 1 MPa). In comparison, effective vertical stress from weight of the overlying rocks is estimated to 14 MPa using the average bulk density of the core. All measurements suggest that our reservoir rock sample is extremely weak with respect to its depth of deposition.

  • 38.
    Juhlin, Christopher
    et al.
    Department of Earth Sciences, Uppsala University, Uppsala universitet.
    Hangx, Suzanne
    Department of Earth Sciences, Utrecht University.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bruckman, Viktor
    Austrian Academy of Sciences, Commission for Interdisciplinary Ecological Studies.
    Energy, Resources & the Environment: Current Status2014In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 59, p. 440-444Article in journal (Refereed)
    Abstract [en]

    The EGU gathers geoscientists from Europe and the rest of the world, covering all disciplines of geosciences. Geoscientific interdisciplinarity is needed to tackle future challenges. A major challenge regards the provision of adequate and reliable supplies of affordable energy and resources obtained in environmentally sustainable ways, which are essential for economic prosperity, environmental quality and political stability around the world. One goal of the ERE division is to be a leading discussion forum for these subjects. The contributions in this issue present some of the challenges that were presented in the ERE division at the EGU General Assembly in 2014.

  • 39. Kadefors, Anna
    et al.
    Olofsson, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Innovation processes and dissemination of research-based knowledge in Swedish rock-engineering: Expweriences in the TRUST GeoInfra project2019Report (Refereed)
    Abstract [en]

    Innovation in the project-based construction industry is perceived as complex and poorly understood. Based on a study of a large collaborative R&D programme to develop knowledge and new engineering methods for Swedish underground construction, we discuss and analyse the innovation system in this area with a focus on dissemination and implementation of research-based knowledge in business projects. The result is primarily based on interviews performed with representatives of clients, contractors, consultants, researchers and funding bodies within the TRUST project. There are two main focus areas: the innovation system level and the TRUST project. The innovation system level describes drivers, organization and processes for engaging in R&D and implementing results within the Swedish Transport Administration (STA), contractor companies and consultancy firms, but also interviewee opinions about the innovation culture in Swedish rock engineering and construction more generally.

    Underground construction is an area where comparatively much research is carried out and university-industry collaboration is lively. Still, our results confirm many of the observations made by previous researchers: the small resources within companies devoted to research and innovation, the importance of champions at the project level, problems as innovation drivers, and the difficulties to disseminate knowledge and implement company level initiatives. The contractor interviews illustrate how sensitive their innovation processes are to chance factors such as timing of new relevant business projects and the experiences and knowledge of the individuals that happen to be assigned to a specific project. In this respect, the client is more in control. However, the interviewed client representatives from STA express the same kind of difficulties in driving innovation more strategically on the organizational level and convince their project managers to open up for R&D tests and new knowledge in their business projects.

    There are many drivers for firms to engage in R&D collaborations with public funding. R&D collaboration provided access to knowledge networks by enabling participation in reference groups and communities such as BeFo. Another important goal, both of companies and of SBUF, was to support MSc and PhD education for future recruitment. Thus, the individuals themselves were often the most important research output. Implementation of results was not found a primary motivation although a more strategic approach was emerging among public organizations and private companies, who put more emphasis than they used to on application in practice of research results. The consultancy company Tyréns was especially active in developing their R&D strategy to support a business model based on premium services. Knowledge development for underground construction was in large part driven by individual specialists based on their contacts in business projects. Centrally defined R&D strategies did not deal explicitly with such technical disciplines, but tended to focus on general goals such as sustainability, or on participation in high profile research collaborations.

    Most specialists within academia as well as industry were involved in several networks and perceived these to provide useful interaction platforms. Research funding was governed by BeFo and SBUF, and these peer networks thus strongly influenced research strategy on a national level. The number of PhDs in industry had increased over the last years, and important informal networks developed over time between these and their former university departments. Such relationships formed the basis for gaining research funding, which is often dependent on industry co-funding.

    When establishing TRUST, the assumption was that a large coordinated R&D project would be better for communicating with industry and implementing results than several smaller projects. However, it turned out to be more or less the other way around. The existing system could handle innovation in projects, but not innovation on the organizational level. This became apparent when trying to find a joint test site. In smaller research projects, access to business projects is provided by project-based individuals with an R&D background and personal contacts. This often requires that site work is going well and that site measurements are found not to cause too much disturbance. Large programs for site measurements involving numerous actors, such as TRUST, call for planning and upfront commitment. However, there was no system on the receiver side – and here the STA was the primary actor – that was able to take the step from a bottom up, ad-hoc, individual based regime to an organizational strategy with national level implications. Thus, the size of the TRUST project turned out to be a major disadvantage.

    In general, the internal innovation capabilities of companies and client authorities need to be developed in order for these to benefit from the collaborative research programs and act upon the knowledge developed. One aspect is that measures should be taken to more explicitly involve business project managers in both R&D and implementation. Innovation capability development is needed especially on the client side, since long term strategies in supplier organizations will not develop if the strategies of the dominant clients is not clear. However, assuming that the geo area in general is largely an open innovation environment, it also seems useful to explore if different actors could perform complementary activities in an industry innovation system. For example, specialist networks both within organizations and on the industry level may be more formally mobilized in external monitoring, strategy development and evaluation. In the future, top management, technically oriented specialists and researchers need to be more aware of how the innovation system works, including the regulatory and contractual environment.

    There is also a need to invest also in research that is relatively far from application. Thus, evaluation processes and output measurement systems should be adapted to how close to implementation the research project is and also assess the need to build capabilities on the receiver side.

  • 40.
    Karig, D. E.
    et al.
    Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Geological perspectives on consolidation of clay-rich marine sediments2003In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 108, no B4, p. 2197-Article in journal (Refereed)
    Abstract [en]

    Experimental consolidation of uncemented clay-rich marine sediments provides information concerning their stress history. A main finding is that some of the well-known behavior of soft sediment deformation in geotechnical applications cannot validly be extrapolated to sediments that have been subjected to higher stresses and longer times of geologic conditions. This study confirms that the yield stress of the uncemented sediment accurately reflects its previous maximum consolidation state. Furthermore, we have identified a new phase of post-yield strain that is associated with higher values of the modified compression index (the slope of the porosity versus the logarithm of effective vertical stress) than that of elastic deformation, but with much lower values than that for primary consolidation. This post-yield behavior is a linear, non-elastic deformation, and is termed tertiary consolidation. Yield stress appears independent of creep time or strain rate, whereas the tertiary-primary consolidation transition is sensitive to these parameters. During post-yield creep (secondary consolidation) the slope of the porosity versus the logarithm of time curve, or the secondary consolidation index, is generally assumed constant. However, this is not valid for claystones at effective vertical stresses above about 1 MPa, where the secondary consolidation index increases with stress. At a given effective vertical stress, the secondary consolidation index also increases with creep times greater than about 105 s (28 h).

  • 41.
    Kukkonen, Ilmo
    et al.
    Geological Survey of Finland.
    Odleiv, Olesen
    Geological Survey of Norway.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Postglacial faults in Fennoscandia: targets for scientific drilling2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 1, p. 71-81Article in journal (Refereed)
    Abstract [en]

    During the last stages of the Weichselian glaciation (ca. 9,000-15,000 years B.P.), reduced ice loads and glacially affected stress fields resulted in active faulting in Fennoscandia with fault scarps up to 160 km long and up to 30m high. These postglacial (PG) faults are usually SE dipping, SW-NE oriented thrusts, and represent reactivated, pre-existing crustal discontinuities. Postglacial faulting indicates that the glacio-isostatic compensation is not only a gradual viscoelastic phenomenon, but also includes unexpected violent earthquakes, suggestively larger than other known earthquakes in stable continental regions. We explore here possibilities and benefits for investigating, via scientific drilling, the characteristics of postglacial faults in northern Fennoscandia, including their structure and rock properties, present and past seismic activity and state of stress, as well as hydrogeology and associated deep biosphere. The research is anticipated to advance science in neotectonics, hydrogeology and deep biosphere studies, and provide important information for nuclear waste disposal, petroleum exploration on the Norwegian continental shelf and studies of mineral resources in PG fault areas. Keywords: Postglacial faults, Fennoscandian Shield, drilling, glaciation, tectonics, seismicity,earthquakes, groundwater flow, groundwater chemistry, deep biosphere

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  • 42.
    Kukkonen, Ilmo T.
    et al.
    Geological Survey of Finland.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Olesen, Odleiv
    Geological Survey of Norway.
    Postglacial fault drilling in northern Europe: workshop in Skokloster, Sweden2011In: Scientific Drilling, ISSN 1816-8957, E-ISSN 1816-3459, no 11, p. 56-59Article in journal (Refereed)
  • 43.
    Kûhn, Michael
    et al.
    GFZ German Research Centre for Geosciences.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Juhlin, Christopher
    Department of Earth Sciences, Uppsala University.
    Bruckman, Viktor
    Austrian Academy of Sciences.
    Kempka, Thomas
    GFZ German Research Centre for Geosciences.
    Martens, Sonja
    GFZ German Research Centre for Geosciences.
    Interdisciplinary Approaches in Resource and Energy Research to Tackle the Challenges of the Future2016In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 97, p. 1-6Article in journal (Refereed)
    Abstract [en]

    The Division Energy, Resources & the Environment (ERE) of the European Geosciences Union (EGU) provides an international platform for scientists from a wide range of fields with the common denominator that their research topics have high societal relevance. The ERE community develops approaches for the solution of global economic prosperity, environmental quality and political stability based on interdisciplinary research on adequate and reliable supplies of affordable energy and other resources in environmentally sustainable ways. This special issue presents contributions of the ERE division at the EGU General Assembly in 2016.

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  • 44.
    Kühn, Michael
    et al.
    GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bruckman, Viktor
    Austrian Academy of Sciences, Commission for Interdisciplinary Ecological Studies, Austrian Academy of Sciences, Section for Mathematics and Natural Sciences.
    Hangx, Suzanne
    Department of Earth Sciences, Utrecht University.
    Juhlin, Christopher
    Department of Earth Sciences, Uppsala University, Uppsala universitet.
    Sustainable Supply of Resources and Energy is a Challenge2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 76, p. 1-6Article in journal (Refereed)
    Abstract [en]

    The European Geosciences Union brings together geoscientists from all over Europe and the rest of the world, covering all disciplines of the earth sciences. This geoscientific inter- and multi-disciplinarity is needed to tackle the challenges of the future. A major challenge for humankind is to provide adequate and reliable supplies of affordable energy and other resources. These should be obtained in environmentally sustainable ways, which is essential for economic prosperity, environmental quality and political stability around the world. This issue gives a general overview of contributions during the General Assembly 2015 in the division for Energy, Resources & the Environment.

  • 45.
    Leonard, J.N.
    et al.
    Texas A&M University, Department of Oceanography, College Station.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Physical properties of sediment and rocks from the d'Entrecasteaux collision zone and North Aoba Basin, Vanuatu island arc1994In: Proceedings of the Ocean Drilling Program. Scientific results: Vanuatu : Covering Leg 134 of the cruises of the drilling vessel JOIDES Resolution, Port of Townsville, Queensland, Australia, to Suva, Republic of Fiji, sites 827-833, 11 October-17 December 1990 / [ed] Chryseis O. Fox, College Station, TX, 1994, p. 511-530Chapter in book (Other academic)
  • 46.
    Mikko, Henrik
    et al.
    Sveriges Geologiska Undersökning.
    Smith, Colby A.
    Sveriges Geologiska Undersökning.
    Lund, Björn
    Institutionen för geovetenskaper, Uppsala Universitet.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Munier, Raymond
    Svensk Kärnbränslehantering AB.
    LiDAR-derived inventory of post-glacial fault scarps in Sweden2015In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 137, no 4, p. 334-338Article in journal (Refereed)
    Abstract [en]

    Pre-existing bedrock structures that reactivated following deglaciation through a combination of tectonic and isostatic stresses are well documented in northern Fennoscandia. Due to their possible implications for seismic hazards, there is a need to document the locations and geometries of these features. The recent availability of a high-resolution, LiDAR-derived, digital elevation model coveringmost of Sweden provides an ideal base upon which to map post-glacial fault scarps that appear to crosscut glacial sediments and landforms. The current mapping project has identified new post-glacial fault scarps in central Sweden, and both refined and rejected scarps previously mapped by aerial photographicinterpretation in northern Sweden. No post-glacial fault scarps, however, were identified in southern Sweden. The current inventory of post-glacial fault scarps is available for download and will be updated as more data become available.

  • 47.
    Morgan, Julia K.
    et al.
    Department of Earth Science, Rice University, Houston, TX.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Consolidation state and strength of underthrust sediments and evolution of the décollement at the Nankai accretionary margin: results of uniaxial reconsolidation experiments2004In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 109, no B03102Article in journal (Refereed)
    Abstract [en]

    Uniaxial reconsolidation experiments conducted on Ocean Drilling Program drill cores along the Muroto Transect of the Nankai accretionary margin demonstrate complex yield and postyield behavior and provide evidence for enhanced strengths within sediments beneath the décollement zone. Tests were conducted on samples collected from similar stratigraphic levels below the décollement and its seaward projection. Consolidation state of the samples increased landward and with depth and was tracked closely by sediment yield stress for all but one of the samples. The sediments, however, exhibited substantial postyield strength: up to 2.8 times the predicted in situ effective vertical stress beneath the protothrust zone. This enhanced strength results from diagenesis that leads to matrix cementation during stable effective stress conditions within the underthrust section. The close correspondence between yield stress and predicted in situ effective stress suggests that despite the cemented state, the sediment matrix remains sensitive to in situ stress conditions. The low yield stress of one sample, collected within ∼40 m of the décollement fault at Site 808, may reflect diagenesis under reduced effective stress conditions, due to postconsolidation increases in pore pressure along the décollement. Due to their cemented state, the strong underthrust sediments resist décollement downcutting beneath the toe of the prism, leading to preferential incorporation of weaker, continuously deforming accreted sediments during shear. Seismogenic slip along the décollement at depth may create stresses in excess of sediment strength, causing shear failure and rapid release of trapped pore fluids feeding high pore fluid pressures along the décollement zone.

  • 48. Morgan, Julia K.
    et al.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Overpressures and lithification state of underthrust sediments along the Nankai accretionary margin: implications for decollement evolution2003In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 84, no 46Article in journal (Other academic)
  • 49.
    Morgan, Julia K. Morgan
    et al.
    Department of Earth Science, Rice University, Houston, TX.
    Sunderland, Elizabeth B.
    Department of Earth Science, Rice University, Houston, TX.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Deformation and mechanical strength of sediments at the Nankai subduction zone: implications for prism evolution and decollement initiation and propagation2007In: The Seismogenic Zone of Subduction Thrust Faults: [MARGINS Theoretical Institute on "The Seismogenic Zone Revisited", held at Snowbird, Utah, March 16 to 21, 2003], New York: Columbia University Press, 2007, p. 210-256Chapter in book (Other academic)
    Abstract [en]

    As in many depositional settings, marine sediments at convergent margins undergo diagenetic changes before, during, and after mechanical consolidation and deformation. These changes influence mechanical behavior within and beneath the prism and along the décollement. To illustrate the interrelations between sediment diagenesis and deformation, we review physical properties and the types and distributions of deformation structures at several ODP and DSDP drill sites from the frontal regions of the Nankai accretionary prism. Both compactive and dilative deformation structures and fabrics are documented, denoting complicated stress paths during consolidation and tectonic deformation. Laboratory deformation experiments conducted on selected samples from these sites also demonstrate enhanced sediment strengths relative to their preconsolidation stress, both above and below the décollement horizon. This mechanical response indicates the presence of intergranular bonding or cementation that allows sediments to resist consolidation and deformation to relatively high stresses. Once their shear strengths are exceeded, however, cemented sediments can undergo rapid failure, leading to transient increases in pore pressures followed by consolidation. This deformation history may account for the localized compactive deformation bands within the prism. An analogous sequence may develop at depth within the underthrust sediments. Stress perturbations, e.g., near the up-dip limit of the seismogenic zone, may locally exceed the enhanced shear strengths of the underthrust sediments, leading to compactive failure and release of trapped pore fluids. Associated increases in pore fluid pressures may enable décollement downcutting and tectonic underplating. The resulting changes in structural and physical properties of the sediments may favor the onset of seismogenic slip along the décollement

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  • 50. Reid, R.P.
    et al.
    Carey, S.N.
    Staerker, T.S.
    Ask, Maria
    Sedimentology of the collision zone between the North d'Entrecasteaux Ridge and New Hebrides island arc: (Sites 827, 828, and 829)1994In: Proceedings of the Ocean Drilling Program. Scientific results, College Station, TX, 1994, p. 73-88Chapter in book (Other academic)
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