[Ohrnberger] Locating Scattered Energy in Vogtland’s Earthquake Swarm Source Area through Double 3D-Array Beamforming and Inter-Event Coda Correlation Imaging

German Title: Locating Scattered Energy in Vogtland’s Earthquake Swarm Source Area through Double 3D-Array Beamforming and Inter-Event Coda Correlation Imaging

Abbreviation: 397

Current Status: approved


Main Applicant:Dr. Matthias Ohrnberger


Resources Recipient

Prof. Dr. Torsten Dahm
Prof. Dr. Frank Krüger


Other Persons


Conveyor Begin: 1 February, 2019
Conveyor End: 31 January, 2022
Conveyor Duration: 36
Year: 2019


Description

We aim to detect and quantify the characteristics of crustal scatterers located within and around the source area of the West Bohemian / Vogtland region from transient  Earthquake signals. The quantification of scattering strength and its dependence on variable angles provides insight into the nature of scatterers as structural elements and  their possible physical relation with the postulated ongoing deep fluid flow. We will exploit the information from the observation of weak coda phases at multiple arrays. In  order to improve the high frequency content of the observations we will install a deep borehole array beneath a classical surface array for the continuous observation of  transient signals as well as the ambient vibration wave field. This 3D-array installation (receiver array / RA) will be used in combination with the reciprocal 3D array recording  geometry known as source array (SA) for consistently locating weak scattered energy close and within the volume of earthquake swarm generation. Furthermore we propose  to use a source to source coda correlation technique to generate an inter-source Green’s function database. This database will be derived from existing swarm data in recent  years but then further augmented by observations at the newly deployed installations. It will be used to derive the velocity structure in the source volume of the swarm region  and will allow investigating not only the spatial but also the temporal character of velocity anomalies as possible cause for swarm triggering or indications for fluid pathways  in depth.