NKS-R ADdGROUND

8th May 2015, Room Aari, Tekniikantie 1, Espoo, Finland

Objective

The goal of the workshop is to identify and share relevant Nordic data for use in numerical modeling of earthquakes in Fennoscandia.

Background

Significant hazard to a site in Fennoscandia is generated from mid-magnitude seismic event with epicenter localized in the proximity. Earthquake source modeling can be used to understand vibrations in areas close to the earthquake epicenters; but source modeling in stable continental region has limited research background. Different modeling techniques were used for modeling fault stresses/rupture in glaciation scenarios (Lund & Schmidt, 2011) and earthquakes Fälth et al (2014). Uncertainty in such complex models is significant. Measured data from earthquakes and/or explosions can be used to calibrate models. This type of data being rare, the goal of the Workshop is to identify and share relevant Nordic data for the purpose.

The workshop had 15 participants and the consortium agreed to collect data for three levels of earthquake as calibration cases for the future
modelling tasks:

• Data from one recent Canadian event (Mw>5) which was well measured for strong earthquakes (VTT and Uppsala University)
• Data from a low magnitude Swedish earthquake measured as close (<20km) to epicentre (Uppsala University)
• Continue with the Kouvola data analysis (ML 2.6)
• Use some micro earthquake data measured in POSIVA’s array (ÅF-Consult)

Workshop program

10.00 – 11.00

• Earthquake hazard estimations for southern Scandinavia (Peter H. Voss)
• Recent developments of the Fennoscandian shield ground motion characterization models (Tommi Vuorinen, Timo Tiira, Björn Lund, Marja Uski)
• Simulation of earthquake rupture using 3DEC (Billy Fälth)

Coffee break

11.20 – 12.20

• Overview of the M4.1 Sveg earthquake of Sep 15, 2014 (Björn Lund)
• Seismic recordings of Posiva (Jouni Saari)
• Characterization of the Kouvola data from 2012 (Vilho Jussila, Ludovic Fülöp)

12.30-13.00 Discussion and conclusions