Dominant seismic noise sources in the Southern Ocean and West Pacific, 2000-2012, recorded at the Warramunga Seismic Array, Australia

• Published in: Geophysical Research Letters
• Main Authors: Reading, Anya M., Koper, Keith, Gal, Martin, Graham, Leon, Tkalčić, Hrvoje, Hemer, Mark
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union
• Subjects: Southern Ocean; Kerguelen; Pacific; Kerguelen Island
• Online Access: http://hdl.handle.net/1885/70738; https://doi.org/10.1002/2014GL060073; https://openresearch-repository.anu.edu.au/bitstream/1885/70738/7/01_Reading_Dominant_seismic_noise_sources_2014.pdf.jpg

Seismic noise is important in determining Earth structure and also provides an insight into ocean wave patterns and long-term trends in storm activity and global climate. We present a long-duration study of seismic noise focused on the Southern Ocean using recordings from the Warramunga Seismic Array, Northern Territory, Australia. Using high-resolution analysis, we determine the seismic slowness and back azimuth of observed seismic noise, microseisms, at hourly intervals through over a decade (2000-2012). We identify three dominant sources of body wave (P) noise in the Southern Ocean which we interpret to originate from a South Atlantic source propagating as PP waves, and Kerguelen Island and Philippine Sea sources propagating as P waves. We also identify surface waves from around the Australian coast. All sources show distinct seasonality and a low, but discernable, interannual variability.