|Title||Using hydroacoustic stations as water column seismometers|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Yildiz S., Sabra K., Dorman L.M, Kuperman WA|
|Journal||Geophysical Research Letters|
|Type of Article||Article|
|Keywords||array processing; CTBTO; earthquake; hydroacoustics; indian-ocean; low frequency; seismometer|
Getting seismic data from the deep oceans usually involves ocean-bottom seismometers, but hydrophone arrays may provide a practical alternative means of obtaining vector data. We here explore this possibility using hydrophone stations of the International Monitoring System, which have been used to study icebergs and T-wave propagation among others. These stations consist of three hydrophones at about the depth of the deep sound channel in a horizontal triangle array with 2km sides. We use data from these stations in the very low-frequency regime (0.01-0.05Hz band) to demonstrate that these stations can also be used as water column seismometers. By differencing the acoustic pressure, we obtain vector quantities analogous to what a seismometer would record. Comparing processed hydrophone station records of the 2004 Great Sumatra-Andaman Earthquake with broadband seismograms from a nearby island station, we find that the differenced hydrophones are indeed a practical surrogate for seismometers.