Blue (a) and fin whale (b) calls recorded off the Western Antarctic Peninsula, showing multipath arrivals. In both examples, paths shown were first, second, and third bounces (marked 1, 2, and 3, respectively); direct path is not visible. Calculated ranges were for the blue whale and for the fin whale. Theoretical contributing bounces for the fin whale path arrivals are shown in part (c), with the thick line representing the first bounce, the medium thickness line for the second bounce, and the thin line for the third bounce. Calling whale location is denoted with a black square and the receiving ARP location is shown by a black circle.
(a) Locations of calling whales (circles) and dates when they were recorded. Squares show ARP locations and gray lines are 1000-, 2000-, and bathymetry contours. Inset shows a larger area of the Western Antarctic Peninsula (dark gray) where the ARPs numbered S1 to S9 were deployed, with area of localizations indicated with a box. (b) Comparison of multipath and hyperbolic localization results for one of the calls recorded on 30 November 2001.
Plot of blue whale received levels versus log of calculated range . Black line is the best-fit line through the data; the slope of this line corresponds to the value of the transmission loss coefficient, , and is . An increase in leads to an increase in the difference from the theoretical model at higher ranges, while a decrease in leads to an increase in the difference at lower ranges.
Results of BELLHOP incoherent transmission loss calculations for Antarctic Peninsula spring conditions at . Solid gray line is the transmission loss at depth, and the dashed line is the loss at depth. Black line is the empirically determined transmission loss, .
Distribution of (a) blue whale call source levels, with the mean of at over the band and (b) fin whale call source levels, with the mean of at over the band .
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