With the support of the Swiss Agency for Development and Cooperation (SDC) and in collaboration with the Guatemalan NGO Vivamos Mejor, the SED is supporting the Guatemalan National Institute for Seismology, Vulcanology, Meteorology and Hydrology (INSIVUMEH) to establish seismic monitoring of Santiaguito, one of Guatemala’s active volcanoes. This collaboration is part of a major SDC project that aims to mitigate the risk from Santiaguito to the local population. Located in southwest Guatemala, Santiaguito is considered to be the volcano with the highest risk in Central America. Tracking seismic activity under the volcano with high precision can allow scientists to better predict eruptive phases. Additional major hazards at Santiaguito also include violent mudflows (lahars) and catastrophic pyroclastic flows, which contain a mixture of rocks, gas, ash and travel very rapidly. These two hazards pose a high risk for the surrounding communities.

INSIVUMEH is currently installing a seismic network on and around the volcano. The role of the SED team is first to help ensure a successful network deployment and data processing. Therefore, researchers from the SED travelled to Guatemala at the end of June to review plans and progress for the seismic network and associated processing. In addition, the team had the opportunity to visit the volcano and better understand the hazards it poses to local communities. The network is expected to be completed this summer. By the end of the year, an event catalogue will become available with examples of seismic records of lahar flows and volcano-tectonic earthquakes. Through previous research projects in Central America to build Earthquake Early Warning (EWARNICA / ATTAC), the SED has established a strong relationship with INSIVUMEH and can rely on previous experience in this region and in Guatemala in particular.

Once the network is operational, the SED team will work to develop scientific tools to improve the monitoring of Santiaguito. During the two-year project, they aim to build a velocity model that will help improve our understanding of volcano-tectonic seismicity and allow the tracking of evolving seismicity. Furthermore, a method will be developed to rapidly detect lahar flows on the volcano's upper slopes so that warnings may be provided to communities downstream.

Das Gebiet der Schwäbischen Alb ist eine bekannte seismische Zone, die wiederholt von Erdbeben erschüttert wird. So ereignete sich 1978 ein Erdbeben der Magnitude 5.7, das circa 8'500 Gebäude beschädigte und 25 Personen verletzte. Bei einem Erdbeben der Stärke 4.2 wie am 9. Juli 2022 können lediglich in der Nähe des Epizentrums vereinzelt leichte Schäden an empfindlichen Gebäuden, die auf lockerem Boden stehen, auftreten.

A magnitude 5 quake is a medium-size quake compared to those felt on Earth, but it’s close to the upper limit of what scientists hoped to see on Mars during InSight’s mission. The science team will need to study this new quake further before being able to provide details such as its location, the nature of its source, and what it might tell us about the interior of Mars.

Shortly after recording the event, Insight went into safe mode - where the spacecraft suspends all but the most essential functions to save energy - due on-going issues with low power associated with mounting dust on the solar panels. It is possible that S1222a is one of the very last events Insight will record. With over 1,300 events already catalogued, it is most likely Mars saved the best until last.

InSight is equipped with a highly sensitive seismometer provided by Centre National d’Études Spatiales (CNES) in France, and a digitizer provided by ETH Zurich in Switzerland. The ETH Zurich team in close collaboration with the Swiss Seismological Service  also coordinates Insight’s Marsquake Service that screen the data for seismic energy, characterize marsquakes and curate the marsquake catalogue.

Earthquakes cannot be prevented nor precisely predicted, but efficient mitigation measures informed by earthquake hazard and risk models can significantly reduce their impacts. The 2020 European Seismic Hazard and Risk Models offer comparable information on the spatial distribution of expected levels of ground shaking due to earthquakes, their frequency as well as their potential impact on the built environment and on people’s wellbeing. To this aim, all underlying datasets have been updated and harmonised – a complex undertaking given the vast amount of data and highly diverse tectonic settings in Europe. Such an approach is crucial to establish effective transnational disaster mitigation strategies that support the definition of insurance policies or up-to-date building codes at a European level (e.g. Eurocode 8) and at national levels. In Europe, Eurocode 8 defines the standards recommended for earthquake-resistant construction and retrofitting buildings and structures to limit the impact due to earthquakes. Open access is provided to both, the European Seismic Hazard and Risk Models, including various initial components such as input datasets.

The updated earthquake hazard model benefits from advanced datasets

Earthquake hazard describes potential ground shaking due to future earthquakes and is based on knowledge about past earthquakes, geology, tectonics, and local site conditions at any given location across Europe. The 2020 European Seismic Hazard Model (ESHM20) replaces the previous model of 2013.

The advanced datasets incorporated into the new version of the model have led to a more comprehensive assessment of the earthquake hazard across Europe. In consequence, ground shaking estimates have been adjusted, resulting in lower estimates in most parts of Europe, compared to the 2013 model, and therewith in the case of Switzerland closer to the national model. With the exception of some regions in western Turkey, Greece, Albania, Romania, southern Spain, and southern Portugal where higher ground shaking estimates are observed. The updated model also confirms that Turkey, Greece, Albania, Italy, and Romania are the countries with the highest earthquake hazard in Europe, followed by the other Balkan countries. But even in regions with low or moderate ground shaking estimates, damaging earthquakes can occur at any time.

Furthermore, specific hazard maps from Europe’s updated earthquake hazard model will serve for the first time as an informative annex for the second generation of the Eurocode 8. Eurocode 8 standards are an important reference to which national models may refer. Such models, when available, provide authoritative information to inform national, regional, and local decisions related to developing seismic design codes and risk mitigation strategies. Integrating earthquake hazard models in specific seismic design codes helps ensure that buildings respond appropriately to earthquakes. These efforts thus contribute to better protect European citizens from earthquakes.

Main drivers of the earthquake risk are older buildings, high earthquake hazard, and urban areas

Earthquake risk describes the estimated economic and humanitarian consequences of potential earthquakes. In order to determine the earthquake risk, information on local soil conditions, the density of buildings and people (exposure), the vulnerability of the built environment, and robust earthquake hazard assessments are needed. According to the 2020 European Seismic Risk Model (ESRM20), buildings constructed before the 1980s, urban areas, and high earthquake hazard estimates mainly drive the earthquake risk.

Although most European countries have recent design codes and standards that ensure adequate protection from earthquakes, many older unreinforced or insufficiently reinforced buildings still exist, posing a high risk for their inhabitants. The highest earthquake risk accumulates in urban areas, such as the cities of Istanbul and Izmir in Turkey, Catania and Naples in Italy, Bucharest in Romania, and Athens in Greece, many of which have a history of damaging earthquakes. In fact, these four countries alone experience almost 80% of the modelled average annual economic loss of 7 billion Euros due to earthquakes in Europe. However, also cities like Zagreb (Croatia), Tirana (Albania), Sofia (Bulgaria), Lisbon (Portugal), Brussels (Belgium), and Basel (Switzerland) have an above-average level of earthquake risk compared to less exposed cities, such as Berlin (Germany), London (UK), or Paris (France).

Developing the models is a joint effort – the role of ETH Zurich

A core team of researchers from different institutions across Europe, including the leading support of members from ETH Zurich, worked collaboratively to develop the first openly available Seismic Risk Model for Europe and to update Europe’s Seismic Hazard Model. They have been part of an effort that started more than 30 years ago and involved thousands of people from all over Europe. These efforts have been funded by several European projects and supported by national groups over all these years.

Researchers from the Swiss Seismological Service (SED) and the Group of Seismology and Geodynamics at ETH Zurich led many of these projects. The SED is also home to EFEHR (European Facilities for Earthquake Hazard and Risk). EFEHR is a non-profit network dedicated to the development and updating of earthquake hazard and risk models in the European-Mediterranean region. ETH Zurich thus holds a central hub function for data collection and processing, open access to earthquake hazard and risk models including all basic data sets, and knowledge exchange.

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