Despite intensive research, scientists cannot predict exactly when and where the next major earthquake will occur. The ERC Synergy project "FEAR" aims at a better understanding of the physics of earthquake processes. To this aims, researchers will generate small earthquakes under controlled conditions at a depth of more than one kilometre and on a scale of ten to one hundred metres. They will measure a variety of earthquake parameters using a dense sensor network and then analyse them. The consortium hopes to gain a better understanding of the dynamics of earthquakes. The new findings will also be used to advance experiments on the safe use of geo-energy and to improve the predictability of earthquakes. The experiments will take at the "Bedretto Lab", a rock laboratory in the Swiss Alps, built by ETH Zurich and the Werner Siemens Foundation. It offers FEAR a unique research environment.

The aim of RISE is to develop tools and measures to reduce future human and economic losses. It is a three-year project financed by the Horizon 2020 programme of the European Commission. It starts in September 2019 and will end in August 2022. RISE is coordinated by ETH Zurich and brings together 19 organisations from across Europe and five international partners.

The key objective of RISE is to advance real-time earthquake risk reduction capabilities for a resilient Europe. With an improved scientific understanding and the use of emerging technologies human and economic losses shall be further reduced. New measures are needed to compliment present efforts in implementing building codes and retrofitting existing structures.

RISE adopts an integrative, holistic view of risk reduction targeting the different stages of risk management. RISE assesses risk dynamically, taking into account varying time scales, locations, and contexts. Improved technological capabilities are applied to combine and link all relevant information to enhance scientific understanding and inform societies.

Examples of the challenges RISE will address are

• Advance real-time seismic risk reduction capacities in of European societies by transitioning to a new concept of dynamic risk.
• Improve short-term forecasting and operational earthquake forecasting by developing and validating the next generation of forecasting models.
• Enhance the quality of earthquake prediction and earthquake forecasting by launching a European collaborative effort for validation and rigorous testing.
• Contribute to the establishment of sound and rational risk reduction procedures
• Improve the preparedness of societies, emergency managers, and long-term recovery management.

RISE is multi-disciplinary, involving earth-scientists, engineering- scientists, computer scientists, and social scientists.

CORE is an EU project funded by the European Commission under Horizon2020 research and innovation programme and involves 19 partners in Europe. Its main objective is to make societies better prepared to face and overcome natural and human-made disasters. Through a transdisciplinary approach, scientists from different fields and various stakeholders from society are involved. The project will seek to put the citizens at the core of disaster resilience and preparedness, supporting communities to enhance their preparedness and rapid recovery.

Defining at best the expected scenarios and the difficulties of individuals and socio-economic structures is essential to make recoveries more effective and efficient. Recommendations and guidelines from CORE will foster a culture of improved preparedness, adaptability, and resilience to risks. In addition, particular attention will be paid to the most vulnerable groups during such disasters: the disabled, the elderly, people with economic difficulties, women, or children. Great attention will also be paid to education in schools, training activities and communication through social media.

InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) is a NASA Discovery Program mission that will deploy a single geophysical lander on Mars to study its deep interior. This is the first comprehensive surface-based geophysical investigation of Mars. The overarching mission goals are to illuminate the fundamentals of formation and evolution of terrestrial (Earth-like) planets by investigating the interior structure and processes of Mars, and more specifically to determine the thickness, structure and composition of the crust, mantle and core, and to measure the rate and distribution of seismic activity and the rate of meteorite impacts. The Mission should land in November 2018 and have a lifetime of about two Earth years. A set of 3-component broadband and short period seismometers (collectively known as SEIS) will be deployed beside the lander. In additional, InSight will also deploy a heat flow probe (HP3), a geodetic experiment (RISE), a magnetometer, and meteorological sensors. Seismological investigations of Mars have so far been based on modeling and synthetic data; starting in 2018, waveform data will be returned from Mars and the era of 'Seismology on Mars' will begin.

Building on our expertise and infrastructure for earthquake monitoring and seismic data processing on Earth, the SED will take the lead role in the building a catalogue of seismic events recorded by SEIS (the 'Marsquake Service’). This service will comprise automatic and reviewed event detection and characterization of local and teleseismic events, as well as meteor impacts. The goal of this service is to provide a comprehensive high-quality event catalogue for Mars that is critical to the SEIS project, in particular as input to the development of Martian crustal and deep structure models.

We are adapting advanced single-seismometer analysis techniques developed on the Earth to provide locations for Martian seismicity. Creating the Marsquake Service is a collaboration between the SED and the SEG groups at the ETH Zurich.

Over the last decade induced seismicity has become an important topic of discussion, especially owing to the concern that industrial activities could cause damaging earthquakes. Large magnitude induced seismic events are a risk for the population and structures, as well as an obstacle for the development of new techniques for the exploitation of underground georesources. The problem of induced seismicity is particularly important for the future development of geothermal energy in Europe, in fact deep geothermal energy exploitation projects such as Basel (2006) and St Gallen (2013) have been aborted due to the felt induced earthquakes they created and an increasing risk aversion of the general population. Induced seismicity is thus an unwanted product of such industrial operations but, at the same time, induced earthquakes are also a required mechanism to increase the permeability of rocks, enhancing reservoir performances. Analysis of induced microseismicity allows to obtain the spatial distribution of fractures within the reservoir, which can help, not only to identify active faults that may trigger large induced seismic events, but also to optimize hydraulic stimulation operations and to locate the regions with higher permeability, enhancing energy production. The project COSEISMIQ integrates seismic monitoring and imaging techniques, geomechanical models and risk analysis methods with the ultimate goal of implementing innovative tools for the management of the risks posed by induced seismicity and demonstrate their usefulness in a commercial scale application in Iceland.

Seismic stations of the COSEISMIQ project (PDF, 0.13 MB)

As a local, versatile, clean, and renewable energy source, geothermal energy can contribute to achieving Switzerland’s energy and climate objectives. Worldwide, numerous geothermal projects have been successfully operating for decades. Unfortunately, some have also been aborted during the reservoir construction or operation phase. Today, adequate risk governance of induced seismicity is perceived as essential for establishing safe and economically viable geothermal projects.

In Switzerland, the subsurface is under the sovereignty of the cantons. Therefore, the cantonal authorities in charge of the permitting, concessioning, and regulatory oversight must have access to independent, state-of-the-art seismological expertise. Furthermore, independent seismic monitoring and competent project oversight are important contributions to risk governance and can build and maintain public acceptance of geothermal projects.

GEOBEST2020+ ensures that the Swiss Seismological Service (SED), the federal agency for earthquakes, can provide seismological expertise and baseline seismic monitoring services to the cantons at no cost and independently of the operators of geothermal projects:

Seismological consulting:

SED experts can support the cantonal authorities with:

• defining induced-seismicity-related content requirements for all relevant cantonal authorizations mandatory for geothermal projects,
• reviewing seismological aspects of permit and concession requests submitted by the project operators,
• providing independent, canton-specific information on geothermal energy and seismicity to the public.

Seismic monitoring and earthquake alarming:

SED can provide the baseline seismic monitoring, including:

• installation of a customized seismological monitoring network,
• automatic real-time earthquake analysis, rapidly reviewed by experienced seismologists,
• earthquake alerting via SMS and email to defined stakeholders,
• providing a rapid preliminary assessment of the natural or human-made origin of seismic events,
• operation of a public, project-specific web page with real-time earthquake and background information,
• operation of a public-access archive of the recorded seismological data.

One of the unsolved challenges for deep geothermal projects is how to mitigate unacceptably large, induced earthquakes. Unfortunately, the processes and conditions underpinning induced seismicity are still not sufficiently well understood to make useful predictions of the likely seismic response to geothermal reservoir development and exploitation. This predictability is further reduced by the sparse knowledge of the hydro-mechanical and geological conditions in the deep underground, and our lacking ability to map them well enough with current technologies. The seismic response to deep geothermal operations can, however, be monitored in real-time by seismological methods. These methods are, therefore, the core element of any traffic light system (TLS) for induced seismicity that was proposed in recent years.

In this project SIAMIS-GT (Improvement of SeIsmological Analysis Methods to better support cantonal authorities in questions related to Induced Seismicity in deep GeoThermal projects), we want to improve seismological analysis methods for monitoring induced seismicity by taking advantage of the waveform similarity observed in these earthquake sequences. The goal is to enable the SED to inform authorities, project developers and the population faster and more accurately about induced earthquakes that may occur during geotechnical projects (e.g., geothermal, mining, tunneling, etc.). We plan to apply similarity and repeating earthquake analysis to induced seismicity to improve the understanding of the source mechanics (i.e., distinction of natural versus induced seismicity, improved detection, localization and characterization). With these methods we also hope to be able to resolve aseismic changes in the subsurface that cannot be resolved using classical methods in real-time.

Figure on the left: Illustration of the basic principles of similarity location. Upper left: waveforms of 7 template earthquakes used for template matching of the Diemtigen swarm. Upper right: Epicenter map of 306 relocated earthquakes color-coded by highest similarity to the 7 templates. Red diamonds indicate the location of the templates. Notice that earthquakes cluster closely around the template they are associated to by waveform similarity. Bottom: Relationship between inter-event distance and waveform similarity for each template with respect to the 306 relocated earthquakes. Color indicates the reference template. It can be clearly seen that similarity decreases strongly with inter-event distance and that individual relationships can be derived for every reference template.

This is the 3rd subproject of the „ENSI – SED-Erdbebenforschung zu Schweizer Kernanlagen“ project.

Subproject 3 aims at studying the relevancy of induced seismicity for the disposal of nuclear waste at geological depth. We will update/develop physics-based modeling of induced seismicity, and we will apply such models to the case of nuclear waste disposal. Moreover, the approach will be validated by reproducing the observations from the “Fault Slip experiment” at Mont Terri underground laboratory. Finally, numerical modeling will be performed to study the seismicity induced by tunnel excavation, as well as to better understand the possible occurrence of seismicity by temperature changes around disposal site. Collaboration with Subproject 1 and 2 will be crucial to properly estimate the hazard and risk of induced seismicity on geological nuclear waste disposal.

Tsunamis do not only happen in oceans, but they do also occur in lakes. As part of an interdisciplinary project entitled “Lake Tsunamis: Causes, Consequences and Hazard” (2017-2021), a workflow for the assessment of the tsunami potential on peri-alpine lakes was developed. The workflow focuses on the tsunami generation by subaqueous mass movements. However, it has been documented that delta failures have caused considerable tsunamis on peri-alpine lakes. So far, delta failures have been widely neglected in the assessment of lake tsunamis; mainly as the triggering and failure mechanisms have not been investigated in detail, and as important parameters such as the thickness and failure volumes are not known.
TSUNAMI-CH Phase 2 aims at extending the workflow for the assessment of the lake tsunami hazard by including delta failures. In addition,  subaerial mass movements are also included as triggers of tsunamis in the workflow. The project, which is funded by the Federal Office for the Environment, consists of 3 work packages (WPs), which are conducted at SED (“WP wave simulation” and “WP synthesis”) and the University of Bern (“WP delta”), in collaboration with the Laboratory of Hydraulics, Hydrology and Glaciology (VAW).

WP delta will characterize various deltas in Swiss peri-alpine lakes, and identify the ones that are susceptible to failure. The resulting geodatabase will store various delta parameters that are relevant for estimating the tsunami potential.

WP wave simulation extends the workflow for the modelling of the tsunami generation, propagation and inundation that was developed in the preceding project. Numerical modelling is conducted with BASEMENT, a freeware simulation tool for hydro- and morphodynamic modelling developed at VAW.

WP Synthesis will document the comprehensive workflow for the assessment of the tsunami hazard.

In the frame of this joint SNF and F.R.S-FNRS project with Belgium partners from the University of Liege, we study the highly variable seismic response of rock instabilities, and related slope failure potential of different mountain morphologies. Systematic ambient-vibration measurements at different rock slope instabilities with array-configurations allow to analyze the influence of layering and material of weathered rocks on the propagation of surface waves and amplification of ground motion. Normal mode vibrations can be observed on various rock structures with pronounced block structures. Application areas were selected in Belgium, Romania and Switzerland.

A main goal of this project is to better understand the relation between wave-field properties like directivity, amplification, and eigenfrequencies, and geotechnical characteristics of rock slope instabilities. Additionally, the influence of weather and climate, as well as long-term changes in the dynamic response of the landslides are examined in detail using semi-permanent or permanent seismic stations. With such installations we study the vibrations of instabilities during earthquakes, which will help to develop models for earthquake induced mass movements.  

Experimental seismological techniques will be further developed with enhanced imaging capability and sensitivity. The expected results have the potential to be applied directly in hazard analysis and risk reduction measures.

In this ETHZ-funded project we analyze ambient vibration and earthquake recordings to characterize and investigate the dynamic response of unstable rock slopes. We perform systematic measurements and interpretation of ambient vibrations at known unstable rock slopes, both with single stations and array-configurations. The eigenfrequencies, eigenmodes, directivity, and amplification of ambient vibrations are identified and compared to geotechnical investigations. The interpretation of recordings targets the estimation of the potential landslide volume and is supported by numerical modeling of seismic wave propagation in fractured media. A classification scheme based on the seismic response has been introduced. Each class indicates specific properties of a rock instability. The two main classes found are the volume-controlled sites and the depth-controlled sites. The extensive database will be extended with instabilities on high-alpine permafrost locations.

Moreover, both short-term and long-term monitoring is undertaken to understand the time evolution of the slope structure. Short-term monitoring is performed at the Alpe di Roscioro (Preonzo) site which represents a unique opportunity to monitor a slope close to collapse. A second semi-permanent station will be installed on the large rock instability above Brienz (Grisons). A main goal of the monitoring is to understand the effect of weather and climate on the dynamic behavior of the rock and its stability. Long-term monitoring is based on the analysis of available past recordings from existing seismic networks, especially for stations located at or very close to steep cliffs. In a later stage of the project, the effect of earthquakes on the rock slope stability will be evaluated using numerical modelling. It will be evaluated, if ambient noise measurements can provide a direct proxy for the seismic vulnerability of rock slope instabilities. The expected results have the potential to be applied directly in hazard analysis and risk reduction measures.

Scientists from the SED are exploring the potential of Earthquake Early Warning (EEW) in Central America. This is a multi-phase project funded by Swiss Agency for Development and Cooperation (SDC) at the Federal Department of Foreign Affairs (FDFA). In Phase 1 (2016-2017), SED worked with colleagues at INETER (a government agency in Nicaragua responsible for Natural Hazards, who operate the national seismic network), to build and implement a prototype EEW system in Nicaragua. In Phase 2 (2018-2020), this prototype system will be extended to other countries in Central America with the collaboration of local scientists, and we will explore how a public EEW could be implemented.

The region suffers from large tsunamigenic earthquakes generated along the subduction zone, and also moderate crustal earthquakes that have in the recent past produced heavy damage, such as the M6.2 1972 earthquake that devastated Managua. The subduction zone events are often characterized by slow rupture velocity (most recently a M7.7 1992 earthquake - the first slow earthquake ever documented - and a M7.3 in 2014)

Earthquake Early Warning (EEW) is a tool that can rapidly characterize on-going earthquakes, and potentially provide seconds to 10s of seconds notification of impending strong shaking in advance of its occurrence. EEW can play an important role as part of a seismic risk reduction program, which is critical in the Central American region that has such a high seismic hazard. Additionally, making a seismic network capable of operating and maintaining an EEW system requires the network to achieve the highest standards in network performance - including station quality, speed and reliability of data communications, and robustness of the seismic network hub that runs the EEW software. Optimal network performance is also critical for other applications such as tsunami warning, volcano monitoring, and enables downstream scientific studies, eg on local Earth structure.

On 9 June 2016, just weeks after the first software was installed and before efforts to optimise had begun, a shallow M6.3 event occurred on the border with El Salvador that was detected by our system after 29s. Though far from the delay time required for operational EEW, this does demonstrate the promise of the existing infrastructure. With an ideal seismic network (all stations fully operational, recording strong motion and with minimal data delay) the existing network density can provide first EEW alerts within 8-12s for shallow on-shore earthquakes. This corresponds to a blind zone on the order of 20-30km around the epicenter where no advanced warning will be available. Outside the blind zone, for large earthquakes, this type of EEW can provide warning in advance of the strongest shaking for areas that will experience shaking of intensity VI on the Modified Mercalli Scale.  

Transfer of EEW capacity from SED to Central American Institutes is feasible because we all use the same basic software for seismic network monitoring - SeisComP3 - that the SED has used to develop EEW. SED use 2 standard algorithms to provide EEW - the Virtual Seismologist and the Finite Fault Detector. We use the EEW Display (EEWD) to deliver desktop alerts to early adopters and testers.

EEW can work in Central America because the seismic networks are already relatively dense and data sharing is well-established and effective - necessary as earthquakes can have impacts beyond a single country.

Currently, EEW alerts in the region are delayed or initially incorrect primarily because the seismic networks are relatively unreliable and not yet optimised for EEW. By adopting a long term strategy that focuses on enabling EEW, including adding additional strong motion stations, this will improve.

The Phase 2 project objectives are to 1) review the performance of, and propose improvements to the seismic network in the region, in an effort to optimise their capacity for EEW; 2) to develop EEW algorithms tailored to the seismicity of Central America, with implementation in standard open source software, and transfer know-how and operation to local monitoring institutions; 3) head towards public EEW by engaging with potential key end-users, civil defence and governments, exploring technical means by which EEW can be provided to public and private users, and communicating with social scientists on what is the most effective EEW message provide to the public, and how to communicate this to the public.

California, Oregon, and Washington are currently implementing a public earthquake early warning (EEW) system, called ShakeAlert. To detect earthquakes and to generate alerts, ShakeAlert feeds data from the seismic and geodetic networks operated along the US West Coast into two algorithms: the point-source EPIC (formerly known as ElarmS and Onsite), and the finite-source Finite-Fault Rupture Detector (FinDer) algorithm. Alert messages from EPIC and FinDer are aggregated into a single alert feed.

ShakeAlert started in 2012 as a demonstration system for EEW and provided warnings of imminent strong ground shaking to a selected group of test users. At that stage, the Virtual Seismologist (VS; Cua and Heaton, 2009), implemented and tested by the SED, was part of the system. In 2013, California passed legislation to implement a public warning system. After the US Congress approved the funding in 2014, the transition to a public system started. A limited public roll-out of ShakeAlert started in California, Oregon, and Washington in the fall of 2018.  About one year later the testing of public alerting on mobile devices (phones) was rolled out in California. Washington, and Oregon followed in 2021. Alerts can be received as Wireless Emergency Alerts (WEA) on mobile devices, as well as through apps (e.g. MyShake, QuakeAlertUSA, and ShakeReadySD), or through a ShakeAlert-powered earthquake alert feature that is integrated into the Android Operating System.

The SED collaborates with the ShakeAlert team (US Geological Survey, Caltech, UC Berkeley, University of Washington, and University of Oregon) in the development,  implementation, and testing of FinDer (Böse et al., 2012; Böse et al., 2015; Böse et al., 2018).

SED installed 3 seismological stations in the surroundings of the Mont Terri rock laboratory (St Ursanne, Canton Jura): 2 in the tunnel (stations MTI01 and MTI02) and 1 at the surface (MTI03). The Engineering Seismology group is in charge of the site characterization of these 3 stations. Therefore, a literature review and geophysical experiments are performed in order to propose velocity models able to reproduce the ground motion observed at these stations.

ArtEmis will design, build, and operate a smart and scalable multi sensor system comprising of about 100-200 novel low-cost geochemical sensors, that will measure with unprecedent spatial and temporal resolution changes in radon concentration in ground water, together with other observables like temperature and acidity.

This project is carried out under a contract with the National Cooperative for the Disposal of Radioactive Waste (Nagra). It provides an independent monitoring of the earthquake activity in the area of the proposed nuclear waste repositories in northern Switzerland. Detailed microseismic analysis will help to identify active fault zones and provide insights into the underlying seismotectonic processes in the vicinity of proposed sites, which has direct implications on the seismic hazard assessment. The SED provides results of this project in a transparent manner and all data acquired are made available for public access (see SED declaration on transparency [link]).

Within this project, the Swiss Seismological Service (SED) constructed ten new seismic stations in northeastern Switzerland and southern Germany to improve monitoring capabilities for very small earthquakes. Monitoring of weak seismic events in this region is challenging, because the study region is densely populated and sediments of the Molasse basin dominate the surface geology. A novel step-wise optimization approach was developed to ensure an optimum configuration of the new stations. To reduce the seismic background noise, three of the ten new sites were equipped with borehole-sensors, located at depths of 120–150 m below the surface. The new stations are fully operational since December 2013 and will observe the local seismicity in northern Switzerland for a minimum of ten years.

The newly installed stations complement the five stations installed in 2003 under a first agreement with Nagra. With these ‘Nagra’ stations, together with stations of the Swiss National Seismic Network and stations of neighboring networks in Germany, the project aims to monitor earthquakes down to magnitudes of 1.0 and smaller in the study area. We intend to achieve an overall catalog completeness of Mc 1.3 throughout northeastern Switzerland and location errors less than 0.5 km in epicenter and less than 2 km in focal depth within the study region. Accurate earthquake locations are essential for seismotectonic interpretations. Within this project we therefore aim to improve location accuracy, especially for focal depths, of past and future earthquakes in the region.

Since 2009, the Swiss Seismological Service is renewing and expanding its strong motion network. During the first phase, a total of 30 new accelerometer stations have been installed between 2009 and 2013, both replacing existing strong motion dial-up stations and installing new stations. During the ongoing second phase, 70 more stations are planned to be installed by 2020, including four borehole installations. The renewal project of the Swiss Strong Motion Network was approved by the Swiss Federal Council in February 2009. The project is monitored and supervised by a steering committee headed by the Swiss Federal Office for the Environment (FOEN).

The goals of the enlargement of the Swiss strong motion network are a better spatial coverage of earthquake-prone regions, a better understanding of site effects and thus the verification and improvement of hazard models.

The epicentral areas of relevant past earthquakes have been instrumented in the first phase, namely Aigle (1584), Glarus (1971), Sarnen (1964), Sion-Sierre (1946), Yverdon (1929), Visp (1855), St. Gallen Rhine Valley (1796/96), Altdorf (1774), Brig (1755), Basel (1356), Churwalden/Vaz (1295/1991), etc. Furthermore, the city areas of Zürich, Geneva, Basel, Bern, Lausanne, St. Gallen, Lucerne, Sion, Solothurn, Locarno, Chur, Sierre are relevant sites for free-field installation.

In the second phase, additional epicentral areas of past earthquakes are targeted: Churwalden (1295), Ardez (1504), Ardon (1524), Arbon (1720), Kreuzlingen (1911), and Moudon (1933), among others. Further urban areas are instrumented as well, e.g. Biel, Fribourg, Neuchâtel, Thun and Winterthur. Another aspect of phase 2 is the densification of the network, especially in earthquake-prone areas such as the Valais.

The site selection is always a trade-off between the scientific objectives and the level of vibration disturbances. Modern stations are sensitive enough to record also small earthquakes, but the signal-to-noise ratio may be too low due to traffic and industries. At all sites, geophysical measurements are performed to characterize the site response. Recorded signals can then be interpreted, and sites classified according to the amplification at the site, which is basic information for improved site-specific seismic hazard studies.

The third phase of this project is split into 3 subtasks with the main goal to improve regional and local seismic hazard assessment in Switzerland; with particular focus to the sites of potential regions of nuclear repositories. These sub-projects are:

Subproject 1 aims to improve models and develop methods for the prediction of strong ground motion in Switzerland at the surface and at depth. Two main approaches are investigated: ground motion prediction equations (GMPEs) and stochastic simulation models. Both approaches require calibration to the local seismicity and careful consideration of their extrapolation to large magnitude events which have, as yet, not been instrumentally recorded in Switzerland. In this context, we study the effect of source- and site-related parameters, as stress drop and kappa.

Subproject 2 is focused on earthquake scenario modeling for Switzerland and exploration of the physical limits on ground motion. Our modeling combines realistic rupture along irregular fault surfaces and wave propagation in complex heterogeneous media at high frequency, with focus on underground repositories. Moreover we investigate the plastic and non-linear behavior of soft sediments when subject to high-amplitude Mach waves, conducting CPT measurements to calibrate our numerical models.

Subproject 3 focuses on numerical modeling the induced seismicity during tunnel excavation. Simulations will be performed using both thermo-hydro-mechanical coupled model and statistical model. We will adapt existing models for induced earthquakes to the conditions typically met in deep geological repositories. Available geomechanical faulting models will be used during the validation and calibration stage. Finally, the results will be used as input for Subproject 1 and 2.

This working group gathers the researchers with competences in site characterization in order to discuss and improve the work performed in different projects, especially for sites with new permanent seismic stations. The available tools for processing, archiving and disseminating are shared within the group. The group is responsible for setting up and updating the SED database for site characterization. The group meets regularly to discuss new results and to review the work before it is published.
So far, the group performed more than 250 ambient-vibration seismic array and MASW measurements, about 7000 single station horizontal-to-vertical spectral ratio measurements to determine the resonance frequencies of the soils, and 10 seismic cone penetration tests (SCPT) to assess the risk of potential liquefaction during earthquakes. Temporary seismic stations are also installed and managed to derive empirical amplification functions at sites of interest.

Spektrum is an ETH Zurich project to translate geophysical techniques for landslide monitoring developed in the section for Engineering Seismology at the into a practical product to solve real-world problems.

Most information available for characterizing and monitoring unstable rock slopes are acquired by sensing displacements at the Earth’s surface, possibly missing critical structural changes at depth. We provide a solution to overcome this gap by measuring ambient vibrations on potentially unstable slopes and rock features. The vibrational properties provide information on the extent of the instability and the degradation of the rock mass – similar to structural health monitoring of large bridges and dams. The technique can be applied for real-time monitoring but also by using temporary and portable sensors for rapid characterization of the slope as a base for in-depth geological investigations.

The Pioneer Fellowship is supported by the ETH Foundation and the Innovation & Entrepreneurship Lab of ETH Zurich.

This is the 1st subproject of the “ENSI – SED-Erdbebenforschung zu Schweizer Kernanlagen” project.

This subproject aims to improve source-scaling and attenuation models and to develop methods for the prediction of strong ground motion in Switzerland both at the surface as well as at depth. Two main approaches are investigated: ground motion prediction equations (GMPEs) and stochastic simulation models. Both approaches require adaptions to the local seismicity and careful consideration of their calibration to Swiss conditions. The Fourier spectral and stochastic models correspond to the current state of research and have some advantages over the empirical attenuation relationships, as it is possible to adjust the model to specific local site conditions. The complete understanding in terms of physical parameterization of such models is crucial in order to decouple different effects, which allow building robust predictive models that scale appropriately to large magnitude events. In this regard, variability in source parameter such as stress drop and corner frequency is crucial. Similarly, variability in site-related attenuation parameter kappa (local intrinsic and scattering attenuation) is also need to be well understood. Developed stochastic and duration models from Japanese data allow the review of the Swiss model for large magnitudes in the different distance ranges and at various rock sites which have, as yet, not been instrumentally recorded in Switzerland. The local weak-to-moderate seismicity is used to calibrate the predictive models. The long-term goal is to develop an improved stochastic simulation model for Switzerland allowing existing uncertainties to be rigorously evaluated and reduced. In future, such models will also allow an assessment of ground motion caused by induced seismicity due to the activation of existing fractures and/or the generation of new fractures. Moreover, we developed, validated, and applied a physics-based stochastic model to characterize high-frequency ground motion at depth in the Fourier domain. The goal of it is to be able to predict future ground motions at deep geological disposals.

This is the 2nd subproject of the „ENSI – SED-Erdbebenforschung zu Schweizer Kernanlagen“ project.

Realistic modeling of earthquake ground motions can be achieved only if the causative fault and the medium where waves propagate are described accurately. To efficiently simulate high-frequency earthquake scenario in Switzerland, we develop a hybrid broadband simulation technique combining state-of-the-art rupture models along irregular fault surfaces and wave propagation in complex heterogeneous media taking into account station-specific scattering parameters. Significant efforts are made to extend the validity of our technique to model ground motion at depth for possible applications at underground repositories. A thorough validation and calibration of sensitive parameters is based on Japanese and Swiss datasets. Along with source and path effects, near-surface site conditions represent an important factor controlling ground motions since soft sediments can significantly amplify the shaking observed during an earthquake. Depending on the level of input ground motion, liquefiable soils have the potential to generate excess water pressure resulting in high-frequency acceleration pulses. Advanced constitutive models of liquefiable soils require the knowledge of so-called dilatancy parameters that describe the potential to generate excess water pressure. These parameters can be determined from field observations by analyzing cone penetration test (CPT) measurements. Accurate modeling of liquefiable soils subject to high-amplitude Mach waves is essential to explore the physical limits of ground motion.