Infragravity wave source regions determined from ambient noise correlation

• Published in: Geophysical research letters Vol. 39; no. 4
• Main Authors: Harmon, Nicholas, Henstock, Timothy, Srokosz, Meric, Tilmann, Frederik, Rietbrock, Andreas, Barton, Penny
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.02.2012; American Geophysical Union; John Wiley & Sons, Inc
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; infragravity waves; ocean bottom seismology; Oceanography; Physical oceanography; Plate tectonics; Pressure gauges; Scientific apparatus & instruments; Seismology; Sumatra; Far East; Asia; Sumatra; Indonesia; models; cross-correlation; propagation; noise; tsunamis; Wave generation; pressure; projection; Ocean bottom; Natural hazards; direction
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2011GL050414

We use a backprojection method to determine dominant directions of ocean infragravity waves from 60–200 s period from cross correlations between 5 ocean bottom differential pressure gauges located off the coast of Sumatra. We observe infragravity waves arriving from all directions, but there is a dominant source direction that represents coherent propagation along the coast from the southeast or from the south. This study demonstrates the effectiveness of our projection technique, which may be applied to past and future seismic data to improve models of ocean infragravity wave generation and tsunami propagation. Key Points OBS data can be used to understand infragravity/tsunami waves Noise cross correlation is used to locate the source of infragravity waves In Sumatra, the dominant source region is from the S. Indian Ocean or the coast