Seismic monitoring is one of the four 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.
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 collected 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. High-quality data from another stimulation in the same location were also gathered in summer 2020.
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.
In the FLEX-EPOS research infrastructure project a national pool of geophysical instruments and multi-disciplinary geophysical superstations is created to solve fundamental research questions in seismology, geomagnetism and geodesy. FLEX-EPOS comprises infrastructure and pool of instruments, which can be used in large numbers in various study areas for short- and long-term data collection. The instrument pool is created, maintained and operated in a national co-operation with four universities (Helsinki, Oulu, Turku, Aalto) and three research institutes (GTK, VTT, FGI).
The greatly expanded observational capability will contribute to science by providing massive new datasets, observations and results, and strengthen and extend the role of Finland in the European Plate Observing System (EPOS). The project is supported by Academy of Finland through Finnish Research Infrastructure (FIRI) funding.
Learn more on the project on the FLEX-EPOS Wiki pages.
Project leader: Ilmo Kukkonen, professor in solid earth geophysics
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.
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.
Automatic seismic event classification
Automatic identification of seismic phases
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.
In the SEISMIC RISK - Mitigation of induced seismic risk in urban environments - project UH-VTT-GTK research consortium is studying, how to mitigate induced seismic risk associated with deep geothermal power stations in the Helsinki capital region. Small low magnitude earthquakes pose a risk to the critical tremor sensitive infrastructure such as hospitals, data centers, underground construction. Risk can be mitigated with transparent permitting, seismic monitoring and regional planning. The project will publish a set of seismic hazard maps of Finland and assess the potential impact of seismic waves on different parts of the capital area via 3D models: shear wave tomography, conceptual soil and bedrock model. In addition the project will study the different roles the national, regional and municipal governance in the wicked permitting processes. It will also study what sort of information and at what level of detail do the authorities need on induced seismicity and associated risks.
We study structure of the Lithosphere in all scales.