As the coronavirus pandemic spreads across various regions with more and more people (semi-)confined, there are multiple observations that manmade environmental noise is reduced. The level of this vibration decrease varies spatially. Here are our contributions:
Two M5+ earthquakes hit Zagreb this morning, causing a lot of damage in the historical centre. The magnitude 5.4 event hit at 6:24 in the morning (local time), the second (M5.0) shortly after 7h. The waveforms are clearly recorded at our test station near Sion, in the Valais, 670 km away. Zooming on the wave onset of the two events reveals a high level of similarity; the earthquakes likely happened on the same fault.
Our project Seismology at School in Nepal and its progress so far has been summarized in an article that was accepted for publication today at Frontiers‘ special volume The Power of Citizen Seismology: Science and Social Impacts. The article, Seismology at School in Nepal: a program for educational and citizen seismology through a low-cost seismic network, is available online.
Welcome to Konstantinos Michailos and Andrew Greenwood who join our research group for the second phase of project OROG3NY.
Konstantinos has recently completed his PhD degree at Victoria University of Wellington, in New Zealand. His work will focus on the spatial and temporal distribution of Himalayan earthquakes, especially in the lower crust.
Andrew’s work focuses heavily on the DIVE project, with the long-term goal to Drill the Ivrea-Verbano zonE, a particular place in the Western Alps where rocks rarely seen on the surface are exposed.
On January 15th, 1934 (Maagh 2nd, 1990 in the Nepali calendar) a disastrous earthquake has hit Nepal. Its date was later selected to hold the National Earthquake Safety Day.
This year, Maagh 2 falls on January 16th, and Nepali people celebrate this event for the 22nd time. The Seismology at School in Nepal project participated with two events:
Pictures of the latter event at schools, and observed waveforms and shaking are shown below. Click on the photo for full-size version download, or get the PDF.
The earthquake highlight in Switzerland in 2019 was the swarm in the Wildhorn-Sanetschpass area which started in early November. An often-asked question is whether the swarm is already over. It is not an easy to question to answer, as there is generally some background seismic activity in the area. The figure below shows the located earthquakes near the recent swarm throughout the year 2019 and until today. Based on this, it seems too early to answer whether the swarm has really finished; for that, a longer observation time will be needed.
Late November Iain Stewart was the guest of the ELSTE Earth science MSc program, and gave a great and enlightgening talk on “Natural hazards: how to communicate to save lives“. The full videorecording can be viewed freely online at this page – highly recommended for those interested!
The seismic swarm in the Valais has started over a month ago, on November 5th. Several earthquakes have been felt in about 10 days, then the intensity of the activity decreased. Yet, smaller earthquakes still continue to occur there, as shown on the graph below.
Another graph showing the even longer term trend will be posted here later.
Our paper lead by Cameron Spooner (Potsdam) on a 3D gravity-constrained model of the Alps has been published in Solid Earth today. The publication is openly available, together with the model files.
Updated information and figure on the Wildhorn seismic swarm will appear in this post.
Nov. 19. 17h48: Decreasing activity over the past days; many micro-events detected by the SED down to magnitude -2.
Nov. 15. 16h45: No earthquake in the past 24 hours, but it would be too early to say the swarm stopped.
Nov. 13. 09h48: Another slightly felt event yesterday afternoon; the swarm continues.
Nov. 12. 09h32: A new felt event last night, and further smaller events.
Nov. 11. 09h48, 18:23: Small events, not felt by the population, continue to occur.
Nov. 9. 11h30: The sequence continues, without new felt event since the previous update. See SED situation report here.
Nov. 8. 09h24: The sequence continues, with new felt events last night.
