On Saturday 10.09.2022 a magnitude 4.7 earthquake happened 15 km from Basel, towards Mulhouse (France). The shaking has been widely felt in Switzerland, all across the plateau, and in a large part of the Alps. So far there are no news of damages. A summary in German and French is available on the news page of the Swiss Seismological Service, and the RTS Téléjournal has reported on the event on Sunday. The closest low-cost seismometer of the school seismology network has recorded the following waveform in Bienne/Biel, and here is a figure showing all recordings at schools.
There are rare events in nature. Today the Liechtenstein parliament was debating the matter of earthquake insurance. Exactly at that time, first a magnitude 2.1, then 32 seconds later a magnitude 3.9 earthquake has shaken the building. The session was temporarily interrupted and the chamber evacuated. (Source: euronews). Here is a video about the event:
An overview of this deadly earthquake two weeks after it occurred has appeared in Nature news. There is limited information available, and a lot remains to be discovered.
La Faculté des Géosciences et de l’Environnement a le plaisir d’accueillir la Prof. Barbara Romanowicz (UC Berkeley et Collège de France) le 23 et 24 juin pour deux séminaires à l’Université de Lausanne:
Conférence public, le jeudi 23 juin à 17h15 (ANT-1129): Les grands tremblements de terre et les raz de marée: pourquoi, quand et comment?
Séminaire spécialisé, le 24 juin à 12h00 (GEO-2130): L’imagerie sismique de la Terre profonde: qu’avons-nous appris depuis 40 ans sur la structure et la dynamique interne de notre planète?
Tomorrow – and it is not a joke – the entire AlpArray Seismic Network data will become publicly open.
A few numbers to mark this event… July 2011: planning and coordination start. May 2015: Memorandum of Understanding signed between numerous universities and observatories. January 2016 to March 2019: 39 months of operation of the entire network. March 2022: several temporary seismological stations are still running, or have become permanent. The total data archive size is on the order of few dozens TeraBytes.
The AlpArray Seismic Network was one of the largest, simultaneously operated, broadband seismological networks in the academic domain, employing hexagonal coverage with station spacing as shown below.
There is persistent debate on the direction and origin of subduction in the Eastern Alps: northward or southward, Adriatic or European plate. The most recent, high-resolution P-wave tomography shows the situation could be a subduction merger, with contribution of material from both sides. The idea is not new, as it has already been proposed 30 years ago, but the latest seismological data from the spatially dense AlpArray and EASI seismic networks allowed to create the sharpest images so far. Full details in our recent publication lead by Jarka Plomerová.
Aujourd’hui est la fin de l’année commémorative organisée à l’occasion du 75e anniversaire du dernier grand séisme en date en Suisse, celui du 25 janvier 1946 en Valais, avec une magnitude de 5.8. Au-delà du site web qui garde la trace des activités, un article dans Le Nouvelliste de ce matin résume nos actions, et notre article sur le Géoblog présente des archives inédites sur l’effet de ce séisme sur les différentes sphères de la Terre.
Around mid-January each year is Nepal’s Earthquake Safety Day. On occasion of the 24th such day (2022 in the western world, 2078 in the Nepali calendar), the Seismology at School in Nepal program has organized a rhetoric contest: videos up to 4 minutes long were to compete on the topic of “The role of schools in earthquake preparedness“. A total of 55 videos have been received, which is much above the expectations – congratulations to all participants on their motivation, and thank you for taking part. Below is a poster showing everyone who entered this contest. The top 3 performers have received an award: Aayushma Pokhrel, Samir Ahamad, and Anup Lamichhane. Congratulations!
Over the past year a series of 12 articles related to orogeny have been published in frame of a special volume with the title Mountain Building. The volume is now complete and openly accessible to all. The contents can be downloaded either as individual articles, as a complete book in PDF, and even as an e-book (EPUB format). Many thanks to all contributors, reviewers and to Frontiers for hosting this work!