Johannes THUN
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Analysis of LP and Tremor events from very high density seismological networks
Personal Project in NEMOH
My research within NEMOH focuses on the analysis of seismic long-period (LP) events on various volcanoes. Whereas volcano-tectonic earthquakes on volcanoes are related to brittle failure of rocks (just like earthquakes), the sources of LP seismicity are still not fully understood. Source processes with fluids and resonance are the most widely accepted models for these sources today. However, due to the difficult volcanic environments, very few studies include data from summit-near stations. The Seismology Lab group at University College Dublin installed several temporary high-density networks in the summit areas of active volcanoes (e.g. Mt Etna, Italy and Turrialba, Costa Rica). The data from stations in the near-field of LP sources (i.e. < 1 – 2 km) show different behaviour than we would expect from a “classical” LP source.
I am working on the integration of broadband data from near-field stations into seismic source inversion. Their special behaviour (more impulsive waveforms, quasi-static displacements, etc.) can add to the understanding of LP sources, but the data have to be handled with special care. For example, we need to widen the frequency band of the inversion, which makes it more difficult to filter noise and other influences, such as tilt signals, out of the data.
Furthermore I am interested in possible links between long-period seismicity and other volcanic processes, such as deformations of volcanic edifices.
Scientific Background
I graduated from Karlsruhe Institute of Technology, Germany, with a Diplom degree in Geophysics in 2011, focusing on seismology and related fields throughout my studies. My final thesis was written on the relation between wind and broadband seismological recordings.
During five months as a research volunteer at the Centre of Exchange and Research in Volcanology in Colima, Mexico in winter 2009/10, my interest was directed increasingly towards the field of volcanology. After my graduation I worked on ambient seismic noise analysis at the Institute of Earth Sciences “Jaume Almera” in Barcelona for about 8 months, before I started my current position in NEMOH and at UCD.
About me
Apart from volcanoes and seismology, I am interested in photography and outdoor activities (including hiking and kayaking)and am a proud member of the totally unofficial NEMOH music corps. I enjoy every aspect of NEMOH, from the intense and very useful network schools and field courses to the social activities (incl. lots of singing and guitars) with our lovely small NEMOH family.
Personal Contacts
Johannes Thun
Geophysics Section
School of Cosmic Physics
Dublin Institute for Advanced Studies
5 Merrion Square, Dublin 2, Ireland
http://www.dias.ie/
http://www.ucd.ie/geophysics
http://www.nemoh-itn.eu
E-mail: johannes.thun
ucdconnect.ie
