Biography
Dr David Craig received an honours bachelor degree in climate and earth systems science from University College Dublin in 2011. Shortly afterwards he joined the Geophysics Research Group at UCD as a Ph.D. student studying sources of ocean generated seismic signals. This involved array-based techniques for source location/separation and a computational aspect. Within iCRAG, his research focuses on the source mechanisms for ocean generated seismicity. General research interests include ocean generated seismic noise, seismic array processing, signal separation and the physics of the Earth, oceans and atmosphere.
Ireland has a highly energetic ocean wave climate and is close to major source regions for ocean generated microseisms. These are faint termors in the Earth which occur naturally and can be studied to reveal information about the characteristics of the sea and also to study climate change. I am currently mapping the source locations for ocean generated microseisms near Ireland with a view to better understanding their sources mechanisms.
Project title: Mapping of noise sources areas and trialling of noise correlation methods in the marine environment, offshore Ireland
Technical description
The generation mechanism for ocean generated microseisms (OGM) and their subsequent propagation to continental regions has led to their use as a proxy for sea-state characteristics and for climate change studies. The region is also the subject of ambient noise interferometry and noise correlation studies. As such it is important to have an understanding of the source distribution observed from the region. Similarly the source distribution is important for wave height quantification using land based seismic data where the proximity of ocean buoys to source regions needs to be understood. Also many modern seismological methods make use of OGM signals. For example, the Earth's crust and upper mantle can be imaged using ``ambient noise tomography``; analysis of the geometric dispersion of surface waves and spectral ratio techniques can provide information on velocity structure; and cross-correlation techniques can be used to monitor seismic velocity changes. For many of these methods an understanding of the source distribution is necessary to properly interpret the results.
Role
- Postdoctoral Researcher
Institution
- DIAS
Research Area
- Enabling Methodologies
Expertise
- Geophysics
