Contact 

Research 

Tools 

Publications 

Teaching 

Workshops 

Dr. Céline Hadziioannou

Junior Professor in Seismology, University of Hamburg

Emmy Noether Fellow, project title: "The origin of Love waves in the ocean generated noise wave field"

Contact:

University of Hamburg
Institute of Geophysics
Bundesstrasse 55
20146 Hamburg -- Germany

email: celine.hadziioannou [at] uni-hamburg.de
Tel. +49 (0)40 42838 2980

Google Scholar
ORCID.ORG/0000-0002-5312-2226

CV

Research

Beside the seismic waves caused by earthquakes, any seismometer anywhere on Earth continuously measures faint vibrations. This heartbeat of the Earth is the signature of ocean waves interacting with the seafloor, generating seismic waves in the process.

From their frequency signature, we know that the strongest sources of seismic noise (with around 7 -- 15 second periods) are generated by ocean waves. However, the precise way in which these ocean waves interact with the solid Earth is not yet understood. For the (vertically polarized) Rayleigh waves, a widely accepted and tested theoretical model exists. However, in particular for the (horizontally polarized) Love waves, which we observe in non-negligible quantities, no such physical explanation exists.

The core of my current research is to understand the origin and behavior of seismic noise sources, and in particular those that generate Love waves. What is the generation mechanism causing the noise? Where are the strongest source regions and how do they change over the seasons? With my group, I address these questions using both observations and numerical simulations.

Variations in the seismic noise also provides us with information about the source phenomena that generate it. Since most of these source phenomena are inherently linked with ocean wave state and the atmospheric excitation thereof, careful examination of seismic noise can contribute climate and weather studies.

The analysis of this ambient seismic noise brings us tools with which we can use to improve our understanding of transient processes in the Earth crust, and produce detailed images of its structure. This forms a second focus of my research. How can we extract information from complex seismic wavefields? What can it tell us about changes in subsurface properties? How do these changes relate to material damage, and when are they precursors to failure? These questions can be adressed across the scales, on different earth systems and beyond. Methods based on ambient seismic noise and coda wave interferometry can be used to monitor seismic fault zones, volcanoes, glaciers and even buildings.

Tools

Rotational Seismology Event Database

Online access to more than 17,000 Earthquake waveforms and processed plots from signals recorded simultaneously by the Wettzell ring laser and a nearby seismometer.

Seismo-Live

Contribution of teaching notebooks, e.g. "Signal Processing", "Ambient Seismic Noise", "Rotational Seismology"

Publications

Students under my supervision are indicated with a star

Teaching

Contributor to Seismo-Live

Surface wave seismology
(MSc, 2018, 2019)

Seismologie
(BSc, 6th Semester, 2017, 2018, 2019)

Seismologie Seminar
(MSc, 2017, 2018, 2019)

Geophysical Data Analysis
(MSc, 2016)

Practical: Noise spectra & polarization
1st TIDES (EU COST) Advanced Training School, Bertinoro (Italy), 1-5 June 2015

Geophysical Data Analysis
(MSc, 2015)

Geophysikalische Datenanalyse
(BSc, 2015)

Geophysical Data Analysis
(MSc, 2014)

ROSE School: Signal Processing and Geophysical Data Analysis
(MSc, winter school 2012)


Workshops

4th COST-TIDES Training School in Prague, Czech Republic (programme committee)
2-7 July, 2018

4th IWGoRS Meeting on rotational seismology in Tutzing, Germany
20-23 June, 2016

AMÜSE PhD conference, Hinterriss, Austria
10-12 June, 2016

Hum workshop at the Center for Advanced Studies in Munich (CAS)
September 12, 2014

4th Quest workshop in Benodet, France
May 19-25, 2013

Neustadt workshop on "Noise and Diffuse Wavefields"
11-14 November 2012

Selected Presentations