Earthquakes in Switzerland and surrounding regions during 2013

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2013. During this period, 699 earthquakes and 208 quarry blasts were detected and located in the region under consideration. With a total of 18 events with local magnitudes ML ≥ 2.5, the seismic activity in the year 2013 was slightly below the average over the previous 38years. Most noteworthy were the two earthquake sequences of St. Gallen (SG) in July and Balzers (FL) in December. The former was induced by reservoir stimulation operations at the St. Gallen geothermal project. The maximum local magnitude in the sequence was 3.5, comparable in size with the ML 3.4 event induced by stimulation operations below Basel in 2006. The sequence of Balzers was associated with an ML 4.1 earthquake in the border region to Liechtenstein. More than 30 aftershocks with magnitudes ranging between ML −0.2 and ML 3.7 were detected in the month following the mainshock. The ML 3.5 St. Gallen and the ML 4.1 Balzers earthquakes were widely felt by the public but no reports on damages are known. The maximum intensity for both events was IV

Earthquakes in Switzerland and surrounding regions during 2013

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2013. During this period, 699 earthquakes and 208 quarry blasts were detected and located in the region under consideration. With a total of 18 events with local magnitudes ML ≥ 2.5, the seismic activity in the year 2013 was slightly below the average over the previous 38years. Most noteworthy were the two earthquake sequences of St. Gallen (SG) in July and Balzers (FL) in December. The former was induced by reservoir stimulation operations at the St. Gallen geothermal project. The maximum local magnitude in the sequence was 3.5, comparable in size with the ML 3.4 event induced by stimulation operations below Basel in 2006. The sequence of Balzers was associated with an ML 4.1 earthquake in the border region to Liechtenstein. More than 30 aftershocks with magnitudes ranging between ML −0.2 and ML 3.7 were detected in the month following the mainshock. The ML 3.5 St. Gallen and the ML 4.1 Balzers earthquakes were widely felt by the public but no reports on damages are known. The maximum intensity for both events was IV

Earthquakes in Switzerland and surrounding regions during 2012

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2012. During this period, 497 earthquakes and 88 quarry blasts were detected and located in the region under consideration. With a total of only 13 events with ML≥2.5, the seismic activity in the year 2012 was far below the average over the previous 37years. Most noteworthy were the earthquake sequence of Filisur (GR) in January with two events of ML 3.3 and 3.5, the ML 4.2 and ML 3.5 earthquakes at a depth of 32km below Zug in February and the ML 3.6 event near Vallorcine in October. The epicentral intensity of the ML 4.2 event close to Zug was IV, with a maximum intensity of V reached in a few areas, probably due to site amplification effect

The GANSSER seismological network in Bhutan

Abstract HKT-ISTP 2013 A

Review on In Situ Acoustic Emission Monitoring in the Context of Structural Health Monitoring in Mines

A major task in mines and even more in underground repositories for nuclear waste is to investigate crack formation for evaluation of rock mass integrity of the host rock. Therefore, in situ acoustic emission (AE) monitoring are carried out in mines as part of geomechanical investigations regarding the stability of underground cavities and the integrity of the rock mass. In this work, the capability of in situ AE monitoring in the context of structural health monitoring (SHM) in mines and in various geological settings will be reported. SHM pointed out, that the AE network is able to monitoring AE activity in rock with a volume up to 10 6 cubicmeter and distances up to 200 m (e.g., 100 m × 100 m × 100 m) in the frequency range of 1 kHz to 150 kHz. Very small AE events with source size in approximately centimeter to millimeter scale are detected. The results show that AE activity monitors rock deformation in geological boundaries due to convergence of the rock. In addition, high AE activity occurs in zones of dilatancy stress in homogenous rock. In conclusion in situ AE monitoring is a useful tool to observe instabilities in rock long before any damage becomes visible