Tutkimus

Instituutin tutkimustoiminnassa painopistealueita ovat olleet seismiset rakennetutkimukset, valvontaseismologiaan liittyvä menetelmäkehitys ja maanjäristystutkimus Fennoskandian alueella. Rakennetutkimukset ja alueellinen maanjäristystutkimus palvelevat niin geofysikaalista kuin geologistakin perustutkimusta Fennoskandian kilven alueella. Seismologian instituutille kuuluvat seismiseen valvontaan liittyvät viranomaistehtävät pelastuspalvelun ja kansainvälisiin sopimuksiin perustuvan ydinkoevalvonnan osalta.

Seismic monitoring is one of the technologies used by the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime to monitor compliance with the Treaty. The objective of seismic monitoring is to detect and locate underground nuclear explosions and to distinguish them from other seismic events that happens daily, such as earthquakes.

The PCA project covers the activities that the Institute of Seismology will carry out in the operation and maintenance of the IMS primary seismic station FINES (PS17), Finland. The purpose of the project is to guarantee that the station meets the requirements of the International Monitoring System with respect to operational performance, technical characteristics, data availability and reliability.

CTBTO: PCA for IMS Primary Seismic Station PS17/FINES

CTBTO website

Project leader: Jari Kortström

In the earthquake seismology group we focus on earthquakes, fault zone structure, modes of deformation along fault zones, and earthquake and fault zone interaction and triggering mechanisms on a local and regional scale. We analyze seismic waves emanated from earthquakes, but extract also information from the ambient seismic wave field or noise. The research depends on the application and development of analysis techniques for estimating earthquake source parameters, for structural imaging and for the monitoring of time dependent changes in crustal and fault zone materials on time scales ranging from seconds to years. Our work is based on processing large seismic data sets (big data at its very best) and has thus multiple connections to physics and atmospheric sciences (wave propagation), mathematics and medical imaging (inverse problems), and computer science (code development).

Seismic imaging constitutes a fundamental building block of Earth Science research that is practiced by a large community and applied across many scales. The analogy between ultrasonic medical sensors and spatially dense seismic arrays opens up an alternative way for seismic imaging that differs from tomographic methods. We research to what extend the near-field phenomenon referred to as “focal spot” in acoustics can provide simultaneous estimates of the local seismic velocity structure, azimuthal anisotropy, and proxies for intrinsic attenuation without solving an inverse problem.

Modern societies critically depend on sustainable natural resource production and renewable energy sources. Geothermal energy is in many ways an advantageous energy source for local heat and electricity production in densely populated areas. The low environmental impact compared to non-renewables, and the independence on atmospheric, climatic or weather patterns that severely constrain wind and solar technologies have led to a growing interest and use of geothermal energy production. The development of deep geothermal energy projects is, however, not without risks. Our group is dedicated to contribute to a sustainable and safe use of deep geothermal energy. We have been collecting an outstanding data set during the stimulation of the St1 Enhanced Geothermal System between 5 and 6 km depth below Otaniemi, Espoo, in summer 2018. The analysis of the induced earthquakes, and of the altered rock properties will help to mature the application of geothermal energy use in Finland. We target a comprehensive understanding of the rock types and their seismic response, their permeability and geochemical properties, and the location of faults; of the local temperature profile, the stress regime and stress orientations; and of the hydrological situation.

Leader: Gregor Hillers, Associate Professor

The European Plate Observation System (EPOS) is coordinating the integrated use of data, models and facilities from spatially separated Solid Earth research infrastructure (RI). The Finnish national initiative is a joint proposal of the Univ. Helsinki and Oulu, FGI, FMI, GTK, MIKES and CSC. The RI consists of permanent and portable seismic and geodetic stations, magnetic observatories, portable electromagnetic arrays, geodynamic modeling and geophysical laboratories. The operation and maintenance of the RI is funded through host organizations annual budget. Upgrading and expanding of the RI and databanks, special campaigns are funded by grants. The Finnish RI are already in EPOS. EPOS is implementing the long term strategic goals of the geoscientific institutes: leading role European Earth processes, natural hazards and resources studies, and easy access to large datasets. We suggest Finland to become full-member of EPOS in 2014 and participates in the construction of EPOS-ERIC.

PI: Annakaisa Korja 

FIN-EPOS website (in Finnish)

EPOS in TUHAT database

People

Niina Junno MSc

Members of the Helsinki University Geodynamics Group (HUGG) study processes involved in deformation of the Earth’s lithosphere. Our research focuses on quantifying the kinematics and dynamics of the tectonic, geomorphic and geodynamic processes that shape Earth’s outer rigid layer primarily using numerical modelling. Our cutting-edge predictive and interpretative numerical tools are connected with observations from the field, and geochronological, geophysical or remote sensing data. We are also actively involved in teaching in the Bachelor’s programme in Geosciences, the Master's programme in Geology and Geophysics, and the new Bachelor’s of Science in English programme that will launch in 2019.

Leader: David Whipp, Associate Professor

More information about the HUGG can be found on the HUGG wiki site.

We develop and evaluate new methods in monitoring seismology. The research is focused in developing automatic detection, location and event classification flows. Utilizing machine learning methods in the center of our research.

Projects

Auto­matic seis­mic event clas­si­fic­a­tion

Auto­matic iden­ti­fic­a­tion of seis­mic phases

People

Timo Tiira, Research director

Jari Kortström, MSc

Marja Uski, Phil. Lic.

Kati Oinonen, MSc

Katriina Arhe, MSc

Toni Veikkolainen, PhD

Our research is focused on determining source mechanisms for recent earthquakes in Finland, on identifying active faults associated with earthquakes, and on gaining informa­tion on the in situ stresses causing earthquakes. We also develop automatic methods for analysing seismic events recorded by a sparse regional network.

Seismic hazard studies associated with nuclear power plants and enhanced geothermal systems are one of the recent topics.

Projects

Pre-instrumental earthquakes

Evolving the Fennoscandian GMPEs (Evogy)

People

Päivi Mäntyniemi, PhD

Marja Uski, Phil. Lic.

Gregor Hillers, Associate Professor

Tommi Vuorinen, MSc

Timo Tiira, Research director

We study structure of the Lithosphere in all scales.

Projects

KOKKY Deep Seismic Sounding in Tuhat Database

SOFI Deep Seismic Sounding in Tuhat Database

Seismicity and 3D seismic velocity structure in Kuusamo area

Seismicity, faults and 3D seismic velocity structure in Pyhäjoki area

Monitoring Network in Pyhäjoki

Tomographic imaging of seismic velocity structure beneath southern and central Finland

A tomographic crustal velocity model of the central Fennoscandian shield

Hyvönen, T., Tiira, T., Korja, A., Heikkinen, P., Rautioaho, E., SVEKALAPKO Seismic Tomography Working Group & Komminaho, K. 2007 julkaisussa : Geophysical Journal International. 168, 3, s. 1210-1226

WARR seismic profiling in Ukraine

COGITO-MIN in Tuhat Database

COGITO-MIN project website

People

Timo Tiira, Research director

Annakaisa Korja, Research director

Kari Komminaho, MSc

Toni Veikkolainen, PhD

Below are some examples of potential thesis topics related to seismology or supervised by personnel from the institute of seismology.

  1. Hydrothermally altered mineralized systems: Seismic reflection properties of rocks (Kukkonen, Koivisto)
  2. Processing and analysis of seismic reflection data in exploration and mining camps (Koivisto, Kukkonen)
  3. Induced seismicity in enhanced geothermal systems (Kukkonen, Korja)
  4. Data processing and interpretation of seismic data from Siilinjärvi phosphate mine for mine planning (Koivisto)
  5. Applicability of Open quake software to Finnish conditions (Mäntyniemi, Seismology)
  6. Automatic assessment of seismic intensity for felt earthquakes in Finland (Mäntyniemi, Seismology)
  7. Harmonization of internet macroseismology in Fennoscandia (Mäntyniemi, Nordic colleagues)
  8. Several projects associated with the analysis of seismic data collected by 100+ stations around the 2018 geothermal reservoir stimulation in Otaniemi/Espoo (Hillers, Seismology)
  9. Several projects associated with crustal and fault zone monitoring and imaging using ambient noise correlations (Hillers, Seismology)
  10. Refocusing and time reversal (Hillers, Seismology)
  11. Automatic identification of seismic signals from frost events using deep learning (Tiira, Seismology)
  12. Detection and identification of glacier based seismic signals in Antarctica using unsupervised machine learning (Tiira, Seismology)
  13. Automatic detection of seismic events in urban areas, comparison of methods (Tiira, Seismology)
  14. Seismic signal onset estimation by combining different methods and machine learning (Tiira, Seismology)
  15. Study of dissimilarities of microearthquakes in concise earthquake populations with self-organizing maps (Tiira, Seismology)
  16. Influence of seismic station locations on data acquired and threshold event size, Kouvola, Finland (Vuorinen, Oinonen, Seismology)
  17. Ablative subduction in the Andes: An alternative mechanism for removal of mantle lithosphere? (Whipp)
  18. Quantifying rates of bedrock landsliding in mountainous regions and their implications for landscape erosion (Whipp)
  19. Effects of orographic precipitation on mountain evolution in 3D (Whipp)
  20. Where does landslide-derived sediment go and how long does it take? (Whipp)
  21. Mapping erosion in steep mountain landscapes using detrital thermochronology (Whipp, international colleagues)
  22. Paleoproterozoic plateaus: Implications for lithospheric evolution and crustal metamorphism (Whipp)
  23. Ground-motion characteristics of induced seismicity compared to natural earthquakes (Vuorinen)
  24. Radiogenic heat production model of the lithosphere based on geochemistry and seismic data (Kukkonen, Veikkolainen)
  25. Geoneutrinos and radiogenic heat production of the Earth (Kukkonen, Veikkolainen)
  26. Tectonothermal environment of the Wiborg rapakivi batholith (Veikkolainen)
  27. Geophysical properties of the Pyhäsalmi area (Veikkolainen)
  28. Low temperature thermochronology Fission track & He-U-Th-methods (Whipp, Kukkonen)
  29. Modeling of thermochronological data (Whipp, Kukkonen)

Below are some examples of the recent thesis titles related to institute of seismology.

  1. Schütt, Jorina, 2018. 3D dynamics of crustal deformation along the western Andean margin. Doctoral thesis.
  2. Aalto, Aleksi, 2017. Development of a Web GIS Application and Data Management Practices for Integrating Geological and Geophysical Data. Master's thesis.
  3. Tuomi, Hilkka, 2016. Seismic forward modelling constraints for seismic ore exploration at the Kylylahti Cu-Co-Zn-Ni-Ag-Au sulfide deposit. Master's thesis.
  4. Vuorinen, Tommi, 2016. New Fennoscandian Empirical Ground Characterization Model. Master's thesis.
  5. Lammi, Hannu, 2015. Numerical Modelling of Mid-Crustal Flow Applied to Svecofennian Orogeny. Master's thesis.
  6. Heinonen, Suvi, 2013. Seismic reflection profiling for massive sulfide exploration in Finland. Doctoral thesis.
  7. Hellqvist, Niina, 2013. FIRE 2 ja 2a -linjojen rakenteen mallintaminen seismistä attribuuttianalyysiä apuna käyttäen. Master’s thesis.
  8. Koskinen, Paula, 2013. Orientation of faults and their potential for reactivation in the present stress field in Finland. Master’s thesis.

Ongoing theses related to institute of seismology include:

  1. Vuorinen, Tommi. Analysis of induced seismicity of Otaniemi Enhanced Geothermal System. Doctoral thesis.
  2. Junno, Niina. Seismic properties of ores and structures controlling ore deposits: new insights from data mining and seismic forward modeling. Doctoral thesis.
  3. Hällsten, Jennifer. Methodological consideration of macroseismic data in Finland: revisiting the Lappajärvi earthquake (ML 3.8) February 17, 1979. Master’s thesis.
  4. Rantanen, Aleksi. Influence of arc magmatism on crustal temperatures and strength in continental subduction zones. Master’s thesis.
  5. Yijun Wang. Tectonics of strain partitioning in the southern Andes of Chile. Master’s thesis.
  6. Ylä-Mella, Lotta. Forward and inverse modelling of cosmogenic radionuclides in high-latitude glaciated landscapes. Master’s thesis.

Seismologian instituutin julkaisut Tuhat-tietokannassa.

Listauksen Seismologian instituutin julkaisuista ennen vuotta 2010 löydät täältä.