12. Geophysics

12.1. Open session in Geophysics

                       ORAL PRESENTATIONS                    

Data acquisition in the North and e-infrastructure by the EPOS-Norway team

Kuvvet Atakan1, Valérie Maupin2 and the EPOS-Norway Consortium3
1Department of Earth Science, University of Bergen, Norway, 2Department of Geosciences, University of Oslo, Norway, 3see https://epos-no.uib.no
Integrating multidisciplinary transnational infrastructures is a key challenge for solid Earth Science. EPOS (European Plate Observatory System) is a European project to integrate existing research infrastructures within the fields of seismology, geodesy, geophysics, geology, rock physics and volcanology in Europe. Within this framework, the EPOS-Norway project is working in several directions, from developing new e-infrastructure to integrate Norwegian Solid Earth data to improving the monitoring capacity in the Arctic, including Northern Norway and the Arctic islands of Jan Mayen, Bear Island and Svalbard. Two main recent developments will be presented.

A prototype of the e-infrastructure to visualize and analyze geophysical and geological data will be demonstrated, and we will also present how we are working to implicate the scientific community in the development of the software.

We will also report on the results from the survey conducted in August-September 2017 to determine the exact locations of the six planned co-located seismological and geodetic stations on Svalbard. The survey was conducted with the vessel Ulla Rinman who set out from Longyearbyen with a crew of scientists and technicians from UiB, Kartverket and UNIS. Svalbard is currently experiencing increased seismic activity in Storfjorden and continued seismic activity in Nordaustlandet, and the new stations could greatly increase our understanding of this activity.

 

Very deep structural contrasts across the Northern Tornquist Zone

Niels Balling1
1Department of Geoscience, Aarhus University, Aarhus, Denmark
The Tornquist Zone defines a major tectonic lineament across Europe. It extends from the Black Sea to the North Sea and separates old Precambrian cratonic units to the east and northeast from younger Phanerozoic tectonic units in Central and Western Europe. In its northern part, this tectonic zone splits into two main elements, the Sorgenfrei-Tornquist Zone (STZ), trending northwest from around the island of Bornholm to the Skagerrak Sea, and, further south, the Thor Suture between palaeo-continents, Baltica and Avalonia.

This presentation is focused on the STZ. Here, a wide range of geophysical studies reveal marked differences in crustal and upper-mantle structure. From shield units in southern Sweden to deep basins in Danish areas, we observe pronounced crustal thinning, increased surface and upper-mantle heat flow and different gravity and magnetic field anomalies. From traveltime (Medhus et al. 2012; Hejrani et al. 2015) and surface wave (Köhler et al. 2015) tomography, very deep structural contrasts, down to 250-300 km, are recently revealed along the STZ as well as further north. A marked, narrow lithosphere transition zone is outlined with high upper-mantle P- and S-wave velocity below Swedish shield areas and low velocities below Danish Basin and most of southern Norway. Despite markedly different crustal structure between Denmark (deep basins) and southern Norway (Scandinavian Mountains), similar low upper-mantle velocities are observed. These results emphasize the significance of the STZ and the importance of including deep structural information in understanding different tectonic evolution and associated contrasting geological environments.

References
Hejrani, B., Balling, N., Jacobsen, B.H. and Tilmann, F. 2015. Upper-mantle P- and S- wave velocities across the Northern Tornquist Zone from traveltime tomography. Geophysical Journal International 203, 437-458.

Köhler, A., Maupin,V. and Balling, N. 2015. Surface wave tomography across the Sorgenfrei-Tornquist Zone, SW Scandinavia, using ambient noise and earthquake data. Geophysical Journal International 203, 284-311.

Medhus, A.B., Balling, N., Jacobsen, B.H., Weidle, C., England, R.W., Kind, R., Thybo, H. and Voss, P. 2012. Upper mantle structure beneath the Southern Scandes Mountains and the Northern Tornquist Zone revealed by P-wave traveltime tomography. Geophysical Journal International 189, 1315-1334.

 

 Magnetic characteristica of Paleogene sediments in Jutland, Denmark.

Claus Beyer1, Per Nørnberg2 and Claus Heilmann-Clausen2
1CB-Magneto, 2Institute of Geoscience, Århus University
During the last decades we have carried out palaeomagnetic work on the Cenozoic sediments in Denmark. Eocene sediments investigated are: The Ølst Formation, including the basal Eocene Stolle Klint Clay, Røsnæs Clay and Lillebælt Clay Formations, and two upper Eocene members of the Søvind Marl Formation: the Moesgård and Kysing members. The magnetic properties vary according to the geochemic environment, biogenic factors and mineralogy, particularly concentration of magnetite.

The Stolle Klint Clay has a weak remanent magnetisation due to the anoxic depositional environment, with its organic content causing degradation iron oxides. The overlying Ølst Formation has a stronger, well defined remanent magnetisation due to its favourable environment for preservation of iron oxides. In both units the remanent magnetisation is sitting in multidomaine grains. A change to high-intensity magnetisation occurs in the Røsnæs Formation due to that the magnetic grain fractions are dominated by single domaine grains (>90%) throughout the rest of the Eocene up till the base of the Moesgaard Member. Separation of the magnetic phase and subsequent analysis by translucent scanning electron microscoping (TEM) identified magnetite grains smaller than 50 nanometers, similar to the ones produced by magnetotactic bacteria. Their occurrence in this stratigraphic interval may be due to the warm clima and/or the marine sedimentary facies. The result is an excellent palaeomagnetic recording which makes it possible to define secondary magnetic components and use them for dating Quaternary tectonic episodes e.g. at Albæk Hoved where Eocene sediments were tilted by the ice.

 

Crustal structure across coastal Nordland (Norway) from teleseismic receiver functions

Anne Drottning1, Christian Schiffer2, Stéphane Rondenay1 and Lars Ottemöller1
1University of Bergen, 2Durham University
The uplift and erosional history of the coastal Nordland region, in northwestern Norway, is of great scientific interest as it may have caused hydrocarbons to accumulate differently than expected across the area (Nyland et al. 1992). Elucidating this history requires a solid understanding of crustal structure in the region. To help address this need, 26 broadband seismic stations were deployed across coastal Nordland from 2013 to 2016, as part of the broader NEONOR2 project. Here, we present preliminary results of an inversion of teleseismic receiver functions computed at these stations, with the aim to map the crustal velocity structure and Moho depth beneath the region. We employ an automated workflow based on the methods of Schiffer (2015) and Svenningsen and Jacobsen (2007), which inverts simultaneously receiver function waveforms and Ps polarizations at discrete frequencies to obtain S velocity structure in the crust and uppermost mantle. The data quality is highly variable from one station to the other. Some stations yield a very clear Moho pulse at relatively shallow depths (~20-30 km). Conversely, other stations return ringy receiver functions that are either associated with complex crustal layering or, more likely, with strong near-station noise and scattering. The robustness of the method and the results is tested with synthetic datasets. The most robust results from high signal to noise ratio stations are integrated into regional maps of seismic velocities and Moho depth.

 

The 3D stress field of Nordland, northern Norway – insights from numerical modelling

Sofie Gradmann1, M Keiding1, O Olesen1 and Y Maystrenko
1Geological Survey of Norway, Trondheim, Norway
The Nordland area in NW Norway is one of the tectonically most active areas in Fennoscandia. It exhibits patterns of extension, which are in contradiction to the first-order regional stress pattern that reflects compression from ridge-push. The regional stress field stems from the interaction of ridge push and GIA (glacial isostatic adjustment); the local stress field mainly results from gravitational stresses, as well as the flexural effects of sediment erosion and re-deposition.

We develop 3D finite element numerical models of crustal scale, using existing geometric constraints from previous geophysical studies. Internal body forces, induced by variations in density, topography or Moho depth, already yield significant deviatoric stresses, which are often omitted in stress models. We show that these can strongly influence the near-surface stress regime. Similarly, existing weakness zones (such as faults) control the local stress field.

We apply the far-field stress fields (GIA, ridge-push, sediment redistribution) as effective force boundary conditions to the sides or base of the model. This way, we can account for all stress sources at once, but can also vary them separately in order to examine their relative contributions to the observed stress and strain rate fields.

We compare our models to the stress and strain observations derived from different recent seismological and geodetic data sets.

 

Relative relocation of earthquakes along the northern North Atlantic ridge using Rayleigh waves

Christian Grude Kolstad1, Valérie Maupin1, Tormod Kværna2, Steven Gibbons2 and Asbjørn Breivik1
1Department of Geosciences, University of Oslo, Norway, 2NORSAR, Norway
Earthquake activity along mid-oceanic ridges is particularly difficult to monitor due to the lack of nearby stations. Precise location of earthquakes is however required in order to reach a better understanding of the relation between the seismic activity and the tectonic mechanisms at play during the geological history of the mid-oceanic ridges.

We present the results from the relative relocation of 153 shallow moderate-size earthquakes along the North Atlantic Mid-Oceanic ridge from Iceland to Svalbard. Rayleigh waves are usually a major and well-recorded seismic phase for mid-oceanic earthquakes. Nearby earthquakes produce very similar Rayleigh waveforms even when recorded at rather distant seismological stations, and cross-correlation provides a good measurement of their time delays. Injected in a double-difference algorithm, this can be used to relocate the earthquakes relative to each other. The mean distance shift is found to be about 8km. Visual inspection shows a better alignment of the seismicity after relocation and plotting on a high-resolution sea-bed map shows that the earthquakes locations are better consistent with tectonic features after relocation. The relocation is also compared with an independent study made in the same area that uses a Bayesian approach to relocate the seismic activity based on a large set of recordings of regional Pn and Sn arrivals.

 

High-resolution seismic investigations of the Caledonian Lower Allochthon and basement transition in Jämtland, Sweden

Peter Hedin1, Christopher Juhlin1, Henning Lorenz1 and Alireza Malehmir1
1Dept. of Earth Science, Uppsala University, Uppsala, Sweden
During August-September 2017 we acquired high-resolution reflection seismic data in the Jämtland region of west-central Sweden to increase our understanding and knowledge regarding mountain building processes. Of particular importance is the nature and extent of deformation within and across the lowermost allochthonous units of the Caledonides, the main orogenic décollement and underlying Precambrian basement of the Fennoscandian Shield. The Lower Allochthon host structures that strike parallel with the orogenic compression in this region. Therefore, deformation zones, faults and fracture systems in the near surface are also of interest since they may be important in controlling the current hydrogeological environment and influence ground water circulation and the transportation of pollutants. The study area is in close connection with a planned 2.5 km deep borehole of the Collisional Orogeny in the Scandinavian Caledonides (COSC) project (Gee et al., 2010) and previous regional seismic (Juhlin et al., 2016) and magnetotelluric (Yan et al., 2017) studies, which will allow interpretation in a regional context.

In addition to these more scientific objectives, the current project presents an opportunity to evaluate and develop equipment and methodology for efficient and versatile acquisition of high-quality multi-purpose reflection seismic data. We used a 500 kg Bobcat-mounted drop-hammer as the seismic source. Recording was done along two perpendicular profiles simultaneously, using 1C and 3C wireless units (20 m separation) and a high-resolution seismic landstreamer comprising 100 fully digital 3C MEMS sensors (2-4 m separation).

The data are currently being processed and the first results will be presented at the conference.

References

Gee, D. G., Juhlin, C., Pascal, C. and Robinson, P., 2010. Collisional Orogeny in the Scandinavian Caledonides (COSC). GFF 132 (1), 29–44, doi: 10.1080/11035891003759188.

Juhlin, C., Hedin, H., Gee, D. G., Lorenz, H., Kalscheuer, T. and Yan, P., 2016. Seismic imaging in the eastern Scandinavian Caledonides: siting the 2.5km deep COSC-2 borehole, central Sweden. Solid Earth 7, 769–787, doi: 10.5194/se-7-769-2016.

Yan, P., Kalscheuer, T. and Hedin, P., Juanatey, M. A. G., 2017. Two-dimensional magnetotelluric inversion using reflection seismic data as constraints and application in the COSC project. Geophysical Research Letters 44(8), 3554–3563, doi:10.1002/2017GL072953.

 

Seismological observations of Landslide and Tsunami in Karrat Fjord, Greenland, June 17 2017

Tine B. Larsen1, Trine Dahl-Jensen1, Peter Voss1, John Clinton2 and Meredith Nettles3
1GEUS, Copenhagen, 2ETH Zürich, 3Columbia University, New York
On June 17, 2017, a large landslide occurred in NW Greenland, around 20 km from the small village of Nuugaatsiaq, population 100 in Karrat Fjord. The slide slipped into the fjord, inducing a large tsunami, which inundated much of the village, producing widespread destruction – 11 houses were swept out to sea, and four people lost their lives.

The slide generated seismic energy equivalent to a magnitude 4.1 earthquake, visible across the globe. Careful examination of the seismic waveforms indicates no triggering tectonic event. The landslide lit up all 30 GLISN stations (http://glisn.info). One station, NUUG, is located in the village of Nuugaatsiaq and recorded the seismic energy generated by the slide and responded to the ground tilt induced by the fluctuating water levels from the resultant tsunami.

The time series from NUUG clearly records both the slide and the resulting inundation events. Seismic waves from the landslide reaching the town had a duration of about 5 minutes. This long duration and the relatively monochromatic, long-period part of the signal that slowly increases in amplitude are indicative of complex landslide signals. The long-period, large-amplitude tsunami waves are seen in the seismograms as signals with a period of 3 min, lasting for over 3 hours.

The long-period signals observed across the GLISN network, and around the globe, are consistent with a landslide source. The long-period signal suggests failure occurred in two or more stages.

Towards a new global crustal model derived from rapid receiver function inversion of GLImER data

Christian Schiffer1, Stéphane Rondenay2, Anne Drottning2 and Lars Ottemöller2
1Department of Earth Sciences, Durham University, 2Department of Earth Science, University of Bergen
Teleseismic receiver functions provide a relatively easy way to image structure in the Earth’s subsurface. Despite its general ease of use, the method often requires substantial user input to yield stable and robust results. This is also the case for the inverse modelling of receiver functions, which can yield highly variable results depending on the choice of independent constraints and model parameterisation used in the inversion workflow. As a consequence, large-scale applications to global datasets have been limited. We developed a generalised receiver function inversion approach to obtain robust estimates of the crustal and uppermost mantle shear-wave velocity structure. The automated and rapid inversion technique uses the polarisation of incident P-waves in conjunction with the original receiver function waveforms to constrain the S-wave structure beneath seismic stations. We apply it to a global receiver function database, GLImER (Global Lithospheric Imagining using Earthquake Recordings), with the aim to construct a new global crustal model consisting of thousands of individual 1D crustal models. We use previous global estimates of Moho depth and intra-crustal structure as starting models and refine these during the inversion. The greatest improvement of our approach over existing ones will be the additional information it provides about layering and absolute S-wave velocity in the upper mantle. Future work includes the integration of absolute P-wave velocity from teleseismic S-wave polarisations into the inversion workflow, something that should yield important new constraint on the composition of the crust and uppermost mantle.

 

Late Mesoproterozoic, Sveconorwegian orogenic mantle preserved beneath SW Fennoscandia, reflected in seismic tomography and assessed by thermal modelling

Trond Slagstad1, Yuriy Maystrenko1, Valerie Maupin2 and Sofie Gradmann1
1Geological Survey of Norway, Trondheim, Norway, 2Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway
The Late Mesoproterozoic Sveconorwegian orogeny in SW Fennoscandia comprised a series of geographically and tectonically discrete events between 1140 and 920 Ma, involving accretion and partial subduction of continental fragments behind an active continental margin (Slagstad et al., 2017). Today, this region is characterised by low seismic velocities compared to other parts of Fennoscandia (Medhus et al., 2012; Gradmann et al., 2013). A channel-like zone with particularly low velocities in the lithospheric mantle beneath SW Norway coincides spatially with the inferred Sveconorwegian continental-margin arc. Based on results from thermal modelling, we argue that the channel-like, low-velocity zone, at least in part, reflects the thermal (radioactive) effects of the refertilised mantle wedge of this continental magmatic arc. Similarly, the generally low seismic velocities in the interior of the orogen are interpreted to reflect refertilisation due to subduction of continental material (cf. Hieronymus & Goes, 2010). Thermal effects from younger tectonic events, such as Permo-Triassic rifting or late Palaeozoic Caledonian orogenesis can be all but ruled out. In contrast, hot mantle material derived from the Iceland plume may have an effect on temperatures beneath SW Norway, but is unlikely to produce the observed tomographic variations. The geological record in SW Fennoscandia suggests that active-margin magmatism terminated as a result of rapid slab roll-back and trench retreat starting at ca. 1 Ga. The rapid shift from active- to passive-margin processes was probably critical to preserve the mantle wedge, and their identification can therefore shed light on how active-margin processes terminated in ancient orogens.

References
Gradmann, S., Ebbing, J. & Fullea, J. 2013: Integrated geophysical modelling of a lateral transition zone in the lithospheric mantle under Norway and Sweden. Geophysical Journal International 194, 1358-1373.

Hieronymus, C.F. & Goes, S. 2010: Complex cratonic seismic structure from thermal models of the lithosphere: effects of variations in deep radiogenic heating. Geophysical Journal International 180, 999-1012.

Medhus, A.B., Balling, N., Jacobsen, B.H., Weidle, C., England, R.W., Kind, R., Thybo, H. & Voss, P. 2012: Upper-mantle structure beneath the Southern Scandes Mountains and the Northern Tornquist Zone revealed by P-wave traveltime tomography. Geophysical Journal International 189, 1315-1334.

Slagstad, T., Roberts, N.M.W. & Kulakov, E. 2017: Linking orogenesis across a supercontinent; the Grenvillian and Sveconorwegian margins on Rodinia. Gondwana Research 44, 109-115.

 

                       POSTER PRESENTATIONS                    

Geological characterization of clayey till using cross-borehole ground penetrating radar.

Espen Bing Svendsen1, Majken C. Looms Zibar1, Kurt Kjær2, Lars Nielsen1 and Bertel Nilsson3
1University of Copenhagen, 2Natural History Museum of Denmark, University of Copenhagen, 3GEUS
Approximately 40% of Denmark is covered by clayey till. Knowledge of the water flow and transport pathways through these glacial deposits is necessary in order to sustainably exploit and protect our water resources. In clayey till, the presence of macropores dominates the transport pathways as they create a three-dimensional network of pathways that enable a much faster water and contaminant transport than through the surrounding fine-grained diffusion-limited clay matrix. These macropores exist as fractures, biopores from burrows and roots, as well as sand lenses. The macropores are non-trivial to map and at present, a low-cost non-invasive technique for mapping such networks does not exist. We aim to use existing ground penetrating radar (GPR) tools to develop such a technique for geological characterization of clayey till. This study will present preliminary results from Havdrup, Eastern Zealand, first of four field sites, and will focus on correlation between cross-hole GPR data and XRF core-scanner acquired major and minor element variation.

 

3D geomodelling workflow using high performance computing – the vuonos and keretti deposits in Outokumpu Mining area, eastern Finland

Eevaliisa Laine1, Heidi Laxtröm1, Jan Westerholm2 and Johan Ersfolk2
1Geological Survey of Finland, 2Åbo Akademi University, Faculty of Science and Engineering
The Outokumpu district hosting a number of ore bodies is located within the Palaeoproterozoic North Karelia Schist Belt. Mining activity started 1913 and several mines have already been closed (e.g. Keretti/Outokumpu and Vuonos) but serve as valuable data sources for ore exploration. Project GECCO combines expertise in high performance computing and geomodelling, and aims to develop tools for faster geological common earth model (CEM) modelling in a powerful computing environment.

This paper demonstrates the GECCO workflow for the area containing historical Keretti and Vuonos massive Cu-Zn-Co and disseminated Ni sulphide ore deposits hosted by a distinct lithological assemblage, the Outokumpu assemblage, consisting of peridotite and serpentinite enveloped by Cr-bearing carbonate-quartz rocks. Geological structures and lithological heterogeneity of the Outokumpu assemblage were modeled by using geostatistical simulations constrained by drill core data, geological cross sections and fault zones. Hundreds of simulated realizations were summarized as stochastic geological 3D models, i.e., 3D voxets populated by probabilities for each rock type. The calculated gravity and magnetic responses were used to validate the alternative geological 3D voxel models and compared with the Vuonos-Keretti 3D model built by traditional 3D modelling. High performance computing using GPU for simulation and visualization made it possible to make gravity and magnetic forward modelling in real time. The suggested approach gives a possibility to analyze uncertainties associated with geological 3D models spaced on sparse data sets.

 

Geophysical modelling of the Leka Ophiolite Complex

Alexander MIchels1, Suzanne McEnroe1 and Christine Fichler1
1Norwegian University Of Science and Technology
The ~497 Ma Leka Ophiolite Complex (LOC) on the island of Leka in central Norway is one of northern Europe’s most complete ophiolites complexes. The LOC is comprised of oceanic lithosphere that formed near the margin of Laurentia in a subduction-initiated setting, was obducted on to Laurentia in the early Ordovician, and later  transferred to Baltica as part of the upper allochthon in the Scandian Orogen.  The LOC has excellent exposures of partially serpentinized mantle rocks, crustal cumulate dunites and wehrlites, the petrologic and geophysical paleo-Moho, gabbro, sheeted dykes and pillow basalts. Here we present a model for the structure of the LOC based on its geophysical and petrophysical properties. This is the first geophysical study of the LOC that utilizes both gravity and magnetic data. New ground-magnetic surveys combined with a recent aeromagnetic survey by NGU are use to model the LOC, and investigate the enhanced magnetization associated with the major faults. The Bouguer gravity high near the center of the island is 50.5 mGal with a magnetic high 2800 nT. Using gravity surveys, new aeromagnetic data and the petrophysical properties of 564 rock samples, three model sections that transect the island northwest to southeast were created. Depth of the base of the model was constrained by the gravity data while magnetic data was used to constrain contacts and structures within the LOC. The new models suggest the depth of the complex is near 2 km and the ultramafic part of the LOC has a synclinal structure.

 

Why the mantle transition zone does not appear to be thinned at plume sites

Thorsten Nagel1, Erik Duesterhoeft2 and Christian Schiffer3
1Department of Geoscience, Aarhus University, Denmark, 2Department of Geoscience, Christian-Albrechts University, Kiel, Germany, 3Department of Earth Sciences, Durham University, Durham, UK
Deep mantle plumes and associated high thermal gradients are expected to cause an upward deflection of phase transitions defining the lower-upper mantle boundary and an overall thinning of the mantle transition zone in receiver function data. We use forward calculation of mineral assemblages, seismic velocities, and receiver functions to explain the common absence of these observations by means of large temperature-dependent variations of seismic velocities in the lower mantle transition zone. At high thermal gradients, primitive mantle compositions display assemblages dominated by majoritic garnet and periclase. Associated seismic velocities would be 5-10 percent lower than for wadsleyite- or ringwoodite-rich assemblages characteristic for undisturbed thermal conditions. The identified low-velocity zone at upwelling sites could cause a miscalculation of the lower-upper-mantle boundary in the order of 20 kilometers. Our results also confirm and explain existing propositions of low velocities in the lower mantle transition zone at plume sites, which are based on the observation of negative conversions in receiver function data in 500-600 kilometers depth.

 

The seismic signature of the Mantle Transition Zone in different geodynamic scenarios

Christian Schiffer1, Kenni Petersen2, Thorsten Nagel2 and Erik Duesterhoeft3
1Department of Earth Sciences, Durham University, 2Department of Geoscience, Aarhus University, 3Insitute of Geosciences, Kiel University
The Mantle Transition Zone (MTZ) is defined by a series of phase transitions that form the transition between upper and lower mantle. At about 410 km, olivine transforms into wadsleyite, at 510 km into ringwoodite and at about 660 km, ringwoodite and garnet decompose into bridgemanite and periclase. These phase changes cause high-amplitude seismic discontinuities as they represent abrupt density and associated seismic velocity steps. The exact pressure and depth at which these occur are dependent of temperature and composition. Therefore, deflections of the phase transitions are to be expected when cold, depleted subducted lithosphere or a warm, possibly enriched mantle upwelling are crossing the MTZ.

These depth-changes for different geodynamic scenarios is one of the most common ways to study lower-upper mantle mass exchange, commonly interpreted from receiver function images. We explore the imaging capability of receiver functions of the MTZ for different subduction and upwelling scenarios using an integrated petrological-modelling-seismological approach to create realistic receiver function images of the MTZ phase transitions. In particular, we develop self-consistent numerical models coupled to the most advanced thermodynamic databases to derive realistic densities and seismic velocities. The generated snapshots are the base for full-waveform seismic modelling and subsequent receiver function processing. Using this synthetic modelling approach, we will explore the effect of different station layouts, noise and dimensions of anomalies.

 

Towards a Finnish Seismic Database – Taming the National Seismological DDSS

Tommi Vuorinen1, Aleksi Aalto1 and Ilmo Salmenperä1
1Institute of Seismology, University of Helsinki
Institute of Seismology, University of Helsinki (ISUH) is responsible for maintaining the Finnish national seismological network (HE). In addition to HE network, ISUH actively collects and employs continuous waveform data from other seismic networks across the Nordic-Baltic region. In addition, data is also gathered and managed from various temporary network installations and active seismic sounding projects. These data and the accompanying metadata streams are combined, analysed and processed, and later combined with the results of the neigbouring countries (where applicable), to provide data, data products and services which can be utilized by researchers, various agencies and the public.

 

ISUH is actively participating in the pan-European solid-earth Research Infrastructure EPOS which will set data management, licensing and distribution standards for the provided DDSS. In order to address the requirements set by EPOS and the practical necessities of managing big data, ISUH is developing a database-driven SeisComP3-compatible solution that will facilitate more diverse, standard-based access to available data and data products.

The database will also enable the development of new services and software, which will help not only in data management and curation but also in processing raw data streams into usable products. Indeed, quality of certain data & data products have already been improved and new software has entered testing during the development and implementation phase of the project.

Top