This study presents long-term statistics on the ambient sound in the Southern Indian Ocean basin based on 2 years of data collected on six widely distributed autonomous hydrophones from 47°S to 4°S and 53°E to 83°E. Daily mean power spectra (10–100 Hz) were analyzed in order to identify the main sound sources and their space and time variability. Periodic signals are principally associated with the seasonal presence of three types of blue whales and fin whales whose signatures are easily identified at specific frequencies. In the low frequencies, occurrence of winter lows and summer highs in the ambient noise levels are well correlated with iceberg volume variations at the southern latitudes, suggesting that icebergs are a major sound source, seasonally contributing to the ambient noise, even at tropical latitudes (26°S). The anthropogenic contribution to the noise spectrum is limited. Shipping sounds are only present north and west of the study area in the vicinity of major traffic lanes. Acoustic recordings from the southern sites may thus be representative of the pristine ambient noise in the Indian Ocean.

1.
Andrew
,
R. K.
,
Howe
,
B. M.
,
Mercer
,
J. A.
, and
Dzieciuch
,
M. A.
(
2002
). “
Ocean ambient noise: Comparing the 1960s with the 1990s for a receiver off the California coast
,”
Acoust. Res. Lett. Online
3
(
2
),
65
70
.
2.
Chapman
,
N. R.
, and
Price
,
A.
(
2011
). “
Low frequency deep ocean noise trend in the Northeast Pacific Ocean
,”
J. Acoust. Soc. Am.
129
(
5
),
EL161
EL165
.
3.
Chapp
,
E.
,
Bohnenstiehl
,
D. R.
, and
Tolstoy
,
M.
(
2005
). “
Sound-channel observations of ice-generated tremor in the Indian Ocean
,”
Geochem., Geophys., Geosyst.
6
(
6
),
1
29
, doi:.
4.
Curtis
,
K. R.
,
Howe
,
B. H.
, and
Mercer
,
J. A.
(
1999
). “
Low-frequency ambient sound in the North Pacific: Long term series observations
,”
J. Acoust. Soc. Am.
105
(
6
),
711
718
.
5.
Dziak
,
R. P.
,
Fowler
,
M. J.
,
Mastumoto
,
H.
,
Bohnenstiehl
,
D. R.
,
Park
,
M.
,
Warren
,
K.
, and
Lee
,
W. S.
(
2013
). “
Life and death sounds of iceberg A53a
,”
Oceanography
26
(
2
),
10
12
.
6.
Hawkins
,
R.
,
Miksis-Olds
,
J.
,
Bradley
,
D. L.
, and
Smith
,
C.
(
2014
). “
Periodicity in ambient noise and variation based on different temporal units of analysis
,”
Proc. Meet. Acoust.
17
,
070035
.
7.
Hildebrand
,
J. A.
(
2009
). “
Anthropogenic and natural sources of ambient noise in the ocean
,”
Mar. Ecol. Prog. Ser.
395
,
5
20
.
8.
Kibblewhite
,
A.
, and
Jones
,
D.
(
1976
). “
Ambient noise under Antarctic sea ice
,”
J. Acoust. Soc. Am.
59
(
4
),
790
798
.
9.
Mackintosh
,
N.
(
1972
). “
Biology of the populations of large whales
,”
Sci. Prog.
60
,
449
469
.
10.
Matsumoto
,
H.
,
Bohnenstiehl
,
D. R.
,
Tournadre
,
J.
,
Dziak
,
R. P.
,
Haxel
,
J. H.
,
Lau
,
A. T.-K.
,
Fowler
,
M. J.
, and
Salo
,
S. A.
(
2014
). “
Antarctic icebergs: A significant natural ocean sound source in the southern hemisphere
,”
Geochem., Geophys., Geosyst.
15
(
8
),
3448
3458
, doi:.
11.
McDonald
,
M. A.
,
Hildebrand
,
J. A.
, and
Wiggins
,
S. M.
(
2006
). “
Increase in deep ocean ambient noise in the Northeast Pacific west of San Nicolas Island, California
,”
J. Acoust. Soc. Am.
120
(
2
),
711
718
.
12.
McDonald
,
M. A.
,
Hildebrand
,
J. A.
,
Wiggins
,
S. M.
, and
Ross
,
D.
(
2008
). “
A 50 years comparison of ambient noise near San Clemente Island: A bathymetrically complex coastal region off southern California
,”
J. Acoust. Soc. Am.
124
(
4
),
1985
1992
.
13.
McKenna
,
M. F.
,
Katz
,
S. L.
, and
Wiggins
,
S. M.
(
2012
). “
A quieting ocean: Unintended consequence of fluctuating economy
,”
J. Acoust. Soc. Am.
132
(
3
),
EL169
EL175
.
14.
Miksis-Olds
,
J. L.
,
Bradley
,
D. L.
, and
Niu
,
X. M.
(
2013
). “
Decadal trends in Indian Ocean ambient sound
,”
J. Acoust. Soc. Am.
134
(
5
),
3464
3475
.
15.
Nieukirk
,
S. L.
,
Stafford
,
K. M.
,
Mellinger
,
D. K.
,
Dziak
,
R. P.
, and
Fox
,
C. G.
(
2004
). “
Low-frequency whale and seismic airgun sounds recorded in the mid-Atlantic Ocean
,”
J. Acoust. Soc. Am.
115
(
4
),
1832
1843
.
16.
Park
,
Y.-H.
, and
Gamberoni
,
L.
(
1997
). “
Cross-frontal exchange of Antarctic Intermediate Water and Antarctic Bottom Water in the Crozet Basin
,”
Deep-Sea Res., Part II
44
(
5
),
963
986
.
17.
Park
,
Y.-H.
,
Roquet
,
F.
,
Durand
,
I.
, and
Fuda
,
J.-L.
(
2008
). “
Large-scale circulation over and around the Northern Kerguelen Plateau
,”
Deep-Sea Res., Part II
55
(
5
),
566
581
.
18.
Perrone
,
A. J.
(
1969
). “
Deep-ocean ambient-noise spectra in the Northwest Atlantic
,”
J. Acoust. Soc. Am.
46
(
3B
),
762
770
.
19.
Ross
,
D.
(
1976
).
Mechanics of Underwater Noise
(
Pergamon
,
New York
), p.
375
.
20.
Royer
,
J.-Y.
,
Chateau
,
R.
,
Dziak
,
R. P.
, and
Bohnenstiehl
,
D. R.
(
2015
). “
Seafloor seismicity, Antarctic ice-sounds, cetacean vocalizations and long-term ambient sound in the Indian Ocean basin
,”
Geophys. J. Int.
202
(
2
),
748
762
.
21.
Samaran
,
F.
,
Stafford
,
K. M.
,
Branch
,
R. A.
,
Gedamke
,
J.
,
Royer
,
J.-Y.
,
Dziak
,
R. P.
, and
Guinet
,
D.
(
2013
). “
Seasonal and geographic variation of southern blue whale subspecies in the Indian Ocean
,”
PLoS One
8
(
8
),
e71561
.
22.
Sirovic
,
A.
,
Wiggins
,
S. M.
, and
Oleson
,
E. M.
(
2013
). “
Ocean noise in the tropical and subtropical Pacific Ocean
,”
J. Acoust. Soc. Am.
134
(
4
),
2681
2689
.
23.
Stafford
,
K. M.
,
Bohnenstiehl
,
D. R.
,
Tolstoy
,
M.
,
Chapp
,
E.
,
Mellinger
,
D. K.
, and
Moore
,
S. E.
(
2004
). “
Antarctic-type blue whale calls recorded at low latitudes in the Indian and Eastern Pacific oceans
,”
Deep-Sea Res., Part I
51
(
2
),
1337
1346
.
24.
Stafford
,
K. M.
,
Chapp
,
E.
,
Bohnenstiehl
,
D. R.
, and
Tolstoy
,
M.
(
2011
). “
Seasonal detection of three types of‘pygmy’ blue whale calls in the Indian Ocean
,”
Mar. Mammal Sci.
27
(
4
),
828
840
.
25.
Stafford
,
K. M.
,
Nieukirk
,
S. L.
, and
Fox
,
C. G.
(
1999
). “
Low-frequency whale sounds recorded on hydrophones moored in the eastern tropical Pacific
,”
J. Acoust. Soc. Am.
106
(
6
),
3687
3698
.
26.
Talandier
,
J.
,
Hyvernaud
,
O.
,
Reymond
,
D.
, and
Okal
,
E. A.
(
2006
). “
Hydroacoustic signals generated by parked and drifting icebergs in the Southern Indian and Pacific oceans
,”
Geophys. J. Int.
165
(
3
),
817
834
.
27.
Tournadre
,
J.
(
2014
). “
Anthropogenic pressure on the open ocean: The growth of ship traffic revealed by altimeter data analysis
,”
Geophys. Res. Lett.
41
(
22
),
7924
7932
, doi:.
28.
Tournadre
,
J.
,
Whitmer
,
K.
, and
Girard-Ardhuin
,
F.
(
2008
). “
Iceberg detection in open water by altimeter waveform analysis
,”
J. Geophys. Res.
113
(
C8
),
1
8
, doi:.
29.
Wagstaff
,
R.
(
2005
). “
An ambient noise model for the Northeast Pacific Ocean basin
,”
IEEE J. Oceanic Eng.
30
(
2
),
286
294
.
30.
Wenz
,
G. M.
(
1962
).“
Acoustic ambient noise in the ocean: Spectra and sources
,”
J. Acoust. Soc. Am.
34
(
2
),
1936
1956
.
31.
Wilcock
,
W. S.
,
Stafford
,
K. M.
,
Andrew
,
R. K.
, and
Odom
,
R. I.
(
2014
). “
Sounds in the ocean at 1–100 Hz
,”
Annu. Rev. Mar. Sci.
6
,
117
140
.
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