International Journal of Geosciences, 2013, 4, 837-843 Published Online July 2013 (
Passive Seismic Deployments from the Lützow-Holm Bay
to Inland Plateau of East Antarctica: The Japanese IPY
Contribution to Structure and Seismicity
Masaki Kanao1, Akira Yamada2, Genti Toyokuni3
1National Institute of Polar Research, Tokyo, Japan
2Geodynamics Research Center, Ehime University, Matsuyama, Japan
3Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science,
Tohoku University, Sendai, Japan
Received April 23, 2013; revised May 26, 2013; accepted June 24, 2013
Copyright © 2013 Masaki Kanao et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic
Plate and surrounding regions. Several international programs had been conducted in wide area of the Antarctic conti-
nent during the International Polar Year (IPY 2007-2008). The “Antarctica’s GAmburtsev Province (AGAP)”, the
“GAmburtsev Mountain SEISmic experiment (GAMSEIS)” as a part of AGAP, and the “Polar Earth Observing Net-
work (POLENET)” were major contributions to the IPY. The AGAP/GAMSEIS was an internationally coordinated
deployments of more than few tens of broadband seismographs over the wide area of East Antarctica. Detailed informa-
tion on crustal thickness and mantle structure provides key constraints on an origin of the Gamburtsev Mountains; and
more broad structure and evolution of the East Antarctic craton and sub-glacial environment. From POLENET data
obtained, local and regional signals associated with ice movements were recorded together with a significant number of
teleseismic events. Moreover, seismic deployments have been carried out in the Lützow-Holm Bay (LHB), East Antarc-
tica, by Japanese activities. The recorded teleseismic and local events are of sufficient quality to image the structure and
dynamics of the crust and mantle, such as the studies by receiver functions suggesting a heterogeneous upper mantle. In
addition to studies on the shallow part of the Earth, we place emphasis on these seismic deployments’ ability to image
the Earth’s deep interior, as viewed from Antarctica, as a large aperture array in the southern high latitude.
Keywords: Passive Seismic Deployments; Lützow-Holm Bay; East Antarctica; Mantle Structure; Earth’s Deep
1. Introduction
Existing permanent stations of the Federation of Digital
Seismographic Network (FDSN) allow resolution of the
structure beneath Antarctica at a horizontal scale of
~1000 km, which is sufficient to detect fundamental
differences in the lithosphere between East and West
Antarctica, but not to clearly define the structure within
each sector. Detection of seismicity around the Antarctic
is limited by the sparse station distribution and the de-
tection level for local earthquakes remains inadequate for
full evaluation of tectonic activity [1]. A strategy of
attaining a sufficient density of seismic stations on the
continent will allow for optimal ray path coverage across
Antarctica and improvement of the resolution of seismic
tomography [2]. In addition to the lithospheric studies,
the teleseismic data have advantages in investigating a
deeper part of Earth’s interior such as lower mantle, D”
layers, the core-mantle boundary (CMB) as well as the in-
ner core as they are effectively a large span array located
in Antarctica.
The International Polar Year (IPY 2007-2008) pro-
vided an excellent opportunity to make significant ad-
vances in seismic deployments to achieve the science tar-
gets. Following the successful “TransAntarctic Mountain
SEISmic experiment (TAMSEIS; [3]) deployment” in
2000-2002, several big geo-science projects were
conducted to study the interior of Antarctic continent and
surrounding region (Figure 1). The original idea of
passive seismic deployments had been modified accor-
ing to the logistical and financial concerns, but remained d
opyright © 2013 SciRes. IJG
Figure 1. Distribution of the seismic (squares) and geophysical stations (GPS; circles) deployed by major projects at the IPY.
The project names are labeled as; JARE-GARNET, AGAP-GAMSEIS and US-TAMSEIS, respectively. All stations in the
Antarctic continent had been contributed to the POLENET program. LHB: the Lützow-Holm Bay; Dome-F: Dome-F station.
by sincere supports from many nations involved in the
Antarctic research. The resultant broadband seismic sta-
tions in Antarctica were put together for initiating the
major international programs [4] during the IPY.
The “Antarctica’s GAmburtsev Province (AGAP; IPY
#147)”, the “GAmburtsev Mountain SEISmic experiment
as a part of AGAP, and the “Polar Earth Observing Net-
work (POLENET;, IPY #185)”
were the largest contributions in establishing a seismic
network in Antarctica at the IPY. Targeting the vast cen-
tral region of East Antarctica, the AGAP/GAMSEIS was
an internationally coordinated deployment of few tens of
broadband seismographs over the crest of the Gambursev
Subglacial Mountains (GSM, around Dome-A), Dome-C
and Dome-F area [5]. The investigations provided detail-
ed information on crustal thickness and mantle structure
and provide key constraints on the origin of the GSM [6],
and more broadly on the structure and evolution of the
East Antarctic craton and underlying upper mantle [7,
Moreover, the seismic deployments between Eastern
Dronning Maud Land and Enderby Land area, by the
Japanese Antarctic Research Expedition (JARE; [9]) sig-
nificantly contributed as a part of both POLENET and
AGAP/GAMSEIS. From the data obtained, local and re-
gional seismic signals associated with ice movements,
oceanic loading and local meteorological variations were
recorded in addition to a significant number of teleseis-
mic events. In this paper, field operations during the IPY
mainly by JARE activities from the Lützow-Holm Bay
(LHB) to the inland plateau area are summarized and the
significance to study the Earth’s interior as well as the
local seismicity is demonstrated. In addition to reviewing
the seismological approaches for the shallow part of the
Earth, we also put weights on the Earth’s deep interiors,
as viewed from Antarctic continent as a large aperture of
seismic arrays in southern high latitude.
2. Passive Deployments over the East
Targeting the underlying structure, dynamics and evo-
lution of the broader part of East Antarctica, the AGAP
was an internationally coordinated program including
sub-groups of air-borne geophysics, seismics and ice-
core drilling [4]. Multi-national collaboration both for
science investigation and field operational logistics by
many nations from USA, Japan, China, France, Italy and
Australia was a significant factor in the success of the
project. Among the whole AGAP, a sub-group named
Copyright © 2013 SciRes. IJG
GAMSEIS deployed few tens of broadband seismo-
graphs over a wide area of the continental ice sheet from
the GSM, Lake Vostok, and in the vicinity of Dome-F
(Figure 1). Although we do not mention the details in
logistics here, a significant number of flights have been
conducted by Twin-Otter aircraft in order to install the
stations on ice sheet.
The seismic instrumentation utilized for GAMSEIS
and POLENET were provided by the Program for Array
Seismic Studies of the Continental Lithosphere (PASS-
CAL) of the Incorporated Research Institutions for Seis-
mology (IRIS). A review of the field operations at re-
mote sites in polar region at IPY, both for Antarctica and
Greenland, are summarized by [10]. The PASSCAL po-
lar instruments were developed with input from the com-
munity of Antarctic seismologists and the main specifi-
cations are as follows [11,12]. Seismometer; Guralp
CMG-3T in a special configuration to operate at 55˚C,
Datalogger; Quanterra Q-330 with flash memory (oper-
ates to 55˚C), Enclosures; insulated vacuum keep at ~
15˚C above ambient without additional heating, Solar
panels and AGM batteries for summer power, Lithium
batteries for winter power, and these instruments were
optimized for ease of deployment from Twin-Otter air-
In addition to the PASSCAL observation system, the
originally coordinated systems were developed by Japan
(at Dome-F and the vicinity stations), and also by the
other research groups of China and France. Regarding
the Japanese instrument system, the same sensor and
data-logger as used by US/PASSCAL were utilized, but
the electric power supply system and enclosures were
developed independently with technical advice from
PASSCAL staff. A continuous data were recorded in the
MiniSEED format, a commonly accepted international
standard, to ease analysis. Logistical and staff support
were provided by the US researchers and staff at AGAP
camp in the installation of the Japanese stations around
Dome-F. Buried beneath the thick ice sheet, the GSM
was characterized by peak elevations of more than ~3000
m above sea level [13]. The new data from GAMSEIS
has also allowed for more detailed investigation of the
crustal structure beneath the GSM and the surrounding
regions [6].
3. Passive Deployments from LHB to Inland
Outside the AGAP/GAMSEIS deployed area along the
continental margins of East Antarctica, several seismic
stations have been deployed in LHB (Figure 2). The
observations have been carried out initially from 1996
until present and serve as the data contribution to PO-
LENET and FDSN. The stations were established on the
outcrops and ice sheet around the continental margins of
LHB. A significant number of teleseismic events, local
earthquakes, and ice-related events within close to the
stations have been recorded. During the IPY, seven sta-
tions were continuously operated at LHB. The obser-
vation systems consisted of a portable broadband seismo-
meter and a data-recorder (Japanese original), combined
with AGM batteries and solar panels. Guralp Systems
CMG-40T seismometers were mainly utilized.
Detailed information for the local array stations in
LHB and operational information are available from the
web-site of NIPR (
The data of LHB array stations were initially stored and
accessible to cooperative researchers through the data li-
brary server of NIPR (POLARIS). After a defined pe-
riod, the data are made available to world data centers of
seismology, such as the Data Management System (DMS)
of IRIS. The global data centers provide data to seis-
mologists studying the polar regions, the Standing Com-
mittee on Antarctic Data Management (SCADM) under
the Scientific Committee on Antarctic Research (SCAR),
as well as the Antarctic Master Directory (AMD) in the
Global Change Master Directory (GCMD) of NASA.
During the IPY, broadband seismic deployments in
LHB were conducted under the umbrella of endorsed
JARE project. By combining with the other big IPY pro-
jects such as AGAP/GAMSEIS, moreover, the deploy-
ments in LHB could provide constraints on the origin of
GSM in terms of understanding the broader structure of
Antarctic Pre-Cambrian craton, underlying upper mantle
and the sub-glacial environment. Detection of seismic
signals from basal sliding of the ice sheet and ice streams
would be expected from the future study, as well as the
detection of outburst floods from the sub-glacial lakes
within the continent.
4. Retrieved Data and Major Scientific
During the IPY, a significant number of teleseismic
events, as well as many local and regional signals were
recorded at the AGAP/GAMSEIS and POELNET
stations. Teleseismic data obtained provide detail infor-
mation on crustal thickness and mantle temperatures be-
neath Antarctica through regional receiver function and
tomography. Data collected by AGAP/GAMSEIS are
capable of providing key constraints on the origin of
GSM as a crustal root associated with ancient orogenic
events [6], and more broadly on the structure and
evolution of the entire East Antarctic craton [7,8,14]. A
map of crustal thickness beneath GSM indicates large
values over 55 km, which imply an ancient mountain
range may have been supported by thick, buoyant crust
[7]. These new images of the crust and upper mantle in
the middle part of East Antarctica aid in understanding
Copyright © 2013 SciRes. IJG
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Figure 2. Distribution of P-S conversion depth points for 410 km (a) and 660 km (b) discontinuities, respectively. Location of
the conversion depth points was obtained by combining seismic station positions in LHB and hypocenters of the utilized tele -
seismic events. Topographic depth variations of the uppe r mantle discontinuities are presented by the color contours (modi-
fied after [9]).
the evolution of Gondwana super-continent during Earth’s
Several kinds of natural seismic signals connected to
the atmosphere—ocean—cryosphere system can be de-
tected in polar regions. The movement of ice is capable
of causing small magnitude earthquakes, generally la-
beled “ice-quakes” (or “ice-shocks”) for their relation-
ship to glacial dynamics [15,16]. Such kinds of cryo-
seismic sources are considered to have been composed of
the movement of ice sheets, sea-ice, oceanic tide-cracks,
oceanic gravity waves, icebergs and the calving fronts of
ice caps. Cryoseismic sources are likely to be influenced
by surface environmental conditions, and their temporal
variations provide indirect evidence of climate change ap-
peared in polar regions.
In addition to ice motion signals, almost all seismic
stations deployed on Earth’s surface record ubiquitous
signals at periods between 4 and 25 s, commonly referred
to as “microseisms”. Microseisms are considered to be
dominated by Rayleigh waves that arise from gravity
waves in the ocean that are forced by surface winds. The
period ranges of microseisms are dictated by the physics
of gravity wave generation, and are constrained by the
speed and extent of Earth’s surface winds [17,18]. On a
global scale, microseism amplitudes are generally highest
during local winter, because nearby oceans are stormier
in winter than in summer [19]. In contrast, we observe
the opposite in polar regions [20]. The evidence can be
explained by the sea-ice extent impeding both the direct
ocean-to-continent coupling and the coastal reflection.
Microseism studies of Antarctica using IPY data have
recently been undertaken with fruitful results [16,20].
5. Velocity Discontinuit ie s i n t h e U p p er
Characteristic seismic evidence in terms of structure and
dynamics of LHB was obtained by JARE local deploy-
ments. Teleseismic data have sufficient quality for usage
of various analyses to clarify the heterogeneous features
of the crust and upper mantle, tectonic evolution of the
region, as well as deep interiors [21,22]. Shear wave ve-
locity models were inverted by fitting synthetic receiver
functions to the observed data in short-period ranges. The
obtained model investigated from azimuthal variations of
the receiver functions represents a slightly dipping crust
mantle boundary toward the coast. Moreover, a gradual
thickened structure of the crust in LHB was identified
from the north toward the south [23]. Variations in crus-
tal thickness along the coast may reflect the tectonic his-
tory involving super-continent evolution, with increasing
metamorphic grade in crystalline crust towards the sou-
thern part of LHB.
Along with the crustal studies, long period receiver
functions (after 0.2 Hz low-pass filter) demonstrate the
depth variations in mantle discontinuities for both 410
km and 660 km in LHB, respectively [9]. The azimuthal
heterogeneities were also identified in both 410 km and
660 km discontinuities in the two azimuth ranges of 20˚ -
50˚ and 200˚ - 260˚. The two back azimuth groups are
almost parallel with the coast of LHB and may indicate
the relationship with the break-up process of Gondwana
super-continent. The evidence of break-up supported by
other studies from teleseismic shear wave anisotropy and
reflection imaging by active source surveys [24].
Local seismicity around the LHB was reported by [16]
(Figure 3). The seventeen events, except for the 1996.
Sep. Mb = 4.6 earthquake in the southern part of Indian
Ocean, had been determined by local stations at LHB.
The all hypocenters are identified to be located along the
coast, otherwise the northern edge of the continental
shelf. Several events may be large ice-quakes associated
with sea-ice dynamics around the bay or in the southern
ocean. Despite the development of local networks in the
last two decades, we can hardly distinguish a difference
Figure 3. Local seismicity around the LHB region from 1987 to 2003 (modified after [16]). These events, except for the 1996.
Sep. Mb = 4.6 earthquake in the Indian Oc ean, had been det ermined by the local seismic network deployed at the LHB.
between waveforms by local tectonic earthquakes and
those of ice-related phenomena. The ice-related signals
can provide unique information for local impact on polar
region involving global climate change.
6. Study on Global Scale Structure
In addition to the bedrock topography, crust and upper
mantle that underlie the Antarctic ice sheet, the teleseis-
mic data obtained by the AGAP/GAMSEIS, POLENET
and JARE have a great advantage on heterogeneous
structure and dynamics of the deep part of Earth’s inte-
rior. The target depth areas are, for instance, the lower-
most layer of the mantle (D" region) and in the core-
mantle boundary (CMB) [21], together with the inner
core [25]. The heterogeneous and anisotropic structure of
these depth ranges could be investigated by using the
teleseismic data retrieved at both polar regions by these
studies, as a large aperture array located in the southern
high latitude. Seismic data from inland Antarctica is ex-
pected to bring images of the Earth’s deep interiors with
enhanced resolution due to the high signal-to-noise ratio
and wide extent of this region, as well as rarity of their
sampling PKIKP paths along the rotation axis of the
Earth as mentioned by [25].
By using the observed teleseismic waveforms detected
by GAMSEIS and POLENET, the synthetic seismograms
calculated by spherical 2.5-D finite-difference methods
were compared to identify the lateral heterogeneity in
realistic Earth’s structure [26]. The source location used
for the analysis is the Fiji earthquake. Compared wave-
forms in the vertical components between synthetic and
observed are in Figure 4, which represent the good
agreement of their waveforms. Although it is required to
improve the more realistic structural model a more de-
tailed seismic velocity model will ultimately be required,
the agreement in the compared waveforms indicated po-
tential of the spherical 2.5-D finite-difference model as a
tool to reveal the deep inner structure of the Earth. The
seismic station distribution by of GAMSEIS and PO-
LENET, moreover, was found to be a sufficient number
to fulfill the special spatial and back-azimuth coverage
over the globe in the requirements for global wave-field
7. Conclusion
The IPY 2007-2008 provided an excellent opportunity to
make significant progresses in geophysical networks of
both polar regions. These advances serve as a crucial
improvement on the permanent global network of FDSN
and such projects as POLENET and other geo-science
bodies and communities. Accumulated high quality data
in Antarctica from POLENET, AGAP/GAMSEIS and
JARE/LHB could be efficiently utilized to clarify the
dynamic seismicity and heterogeneous structure of the
Earth, particularly around the East Antarctica. Seismic
deployments could efficiently study the crust and upper
mantle, as well as the Earth’s deep interior, including
features such as the CMB and the lowermost mantle
layer (the D” region). These studies also provide signifi-
cant insight into the characteristics of seismicity associ-
ated with global environmental change. From the data
obtained at IPY, local and regional seismic signals asso-
ciated with ice sheet movement and meteorological
variations were recorded. The detection of these signals
from the phenomenon at the base of the ice sheet, such as
outburst floods from sub-glacial lakes are expected from
Copyright © 2013 SciRes. IJG
Figure 4. (Right) Seismic stations in Antarctica used for comparison between synthetic and observed seismograms. FDSN
stations (orange), AGAP-GAMSEIS (red) and POLENET in West Antarctica (blue), respectively. (Left) Comparison of the
vertical components of the Fiji teleseismic event, between synthetic waveforms by the spherical 2.5-D finite-difference method
(red lines) and the observed waveforms (black broken lines) for several stations in Antarctica. The IRIS network and station
code is represented at left side of each trace. Arrival times correspond to pP and S phases are raveled in the first waveform
trace (ZM GM02) (modified after [26]).
detailed analyses. In addition to conventional seismo-
logical approaches for the shallow part of the Earth, we
place significant emphasis on these arrays’ ability to im-
age the Earth’s deep interior, as viewed from Antarctica,
as a large aperture array in the southern high latitude.
8. Acknowledgements
The authors would like to express our special apprecia-
tion to the many collaborators in the IPY projects for
AGAP (Prof. R. Bell and Dr. M. Studinger of Lamont-
Doherty Earth Observatory of Columbia University and
others), GAMSEIS (Profs. D. A. Wiens of Washington
University in St. Louis and A. A. Nyblade of Pennsyl-
vania State University, and others) and POLENET (Prof.
T. Wilson and Dr. S. Konfal of the Ohio State University
and others). We would like to express our sincere appre-
ciation of our many collaborators in the Japanese Antarc-
tic Research Expeditions (JARE; Prof. Kazuyuki Shirai-
shi, Director-in-General of NIPR and others). They
would like to express their sincere thankfulness for Prof.
F. Davey of the Institute of Geological and Nuclear Sci-
ences Ltd, New Zealand, and Prof. A. K. Cooper of the
Department of Geological and Environmental Sciences,
Stanford University, for their critical reviews and useful
comments under preparation of the manuscript.
[1] A. M. Reading, “On Seismic Strain-Release within the An-
tarctic Plate,” In: D. K. Futter, et al., Eds., Antarctica: Con-
tributions to Global Earth Sciences, Springer-Verlag, New
York, 2006, pp. 351-356.
[2] M. H. Ritzwoller, N. M. Shapino, A. L. Levshin and G.
M. Leahy, “Crustal and Upper Mantle Structure Beneath
Antarctica and Surrounding Oceans,” Journal of Geo-
physical Research, Vol. 106, No. 12, 2001, pp. 30645-
30670. doi:10.1029/2001JB000179
[3] D. A. Wiens, S. Anandakrishnan, J. P. Winberry and M.
A. King, “Simultaneous Teleseismic and Geodetic Ob-
servations of the Stick-Slip Motion of an Antarctic Ice
Stream,” Nature, Vol. 453, No. 7196, 2008, pp. 770-774.
[4] T. Wilson and R. Bell, “Earth Structure and Geodynamics
at the Poles,” Understanding Earths Polar Challenges:
International Polar Year 2007-2008, 2011, pp. 273-292.
[5] D. A. Wiens, “Broadband Seismology in Antarctica: Re-
cent Progress and Plans for the International Polar Year,”
Proc. Inter. Symp.—Asian Collaboration in IPY 2007-
2008, Tokyo, 2007, pp. 21-24.
[6] S. E. Hansen, A. A. Nyblade, D. S. Heeszel, D. A. Wiens,
P. J. Shore and M. Kanao, “Crustal Structure of the Gam-
burtsev Mountains, East Antarctica, from S-Wave Re-
ceiver Functions and Rayleigh Wave Phase Velocities,”
Earth and Planetary Science Letters, Vol. 300, No. 3-4,
2010, pp. 395-401. doi:10.1016/j.epsl.2010.10.022
[7] D. S. Heeszel, D. A. Wiens, A. A. Nyblade, S. E. Hansen,
M. Kanao, M. An and Y. Zhao, “Rayleigh Wave Con-
straints on the Structure and Tectonic History of the Gam-
burtsev Subglacial Mountains, East Antarctica,” Journal
of Geophysical Research, Vol. 118, No. 5, 2013, pp. 1-16.
[8] A. J. Lloyd, A. A. Nyblade, D. A. Wiens, P. J. Shore, M.
Kanao, S. E. Hansen and D. Zhao, “Upper Mantle Seis-
Copyright © 2013 SciRes. IJG
mic Structure beneath the East Antarctic Shield from
Body Wave Tomography: Implications for the Origin of
the Gamburtsev Subglacial Mountains,” Geochemistry,
Geophysics, Geosystems, Vol. 14, No. 4, 2013, pp. 902-
920. doi:10.1002/ggge.20098
[9] M. Kanao, Y. Usui, T. Inoue and A. Yamada, “Broadband
Seismic Deployments for Imaging the Upper Mantle
Structure in the Lützow-Holm Bay Region, East Antarc-
tica,” Geophysical Journal International, Vol. 2011, 2011,
pp. 1-15. doi:10.1155/2011/272646
[10] K. Anderson and T. Parker, “Polar Operations,” IRIS 2009
Annual Report—Twenty Five Years of IRIS, 2009, pp.
[11] K. Anderson, B. Beudoin and T. Parker, “IRIS/PASSCAL
Polar Power/Comms,” MRI Year 1 Midseaon Report, 2007,
14 p.
[12] D. A. Wiens, “Autonomous Polar Observing Systems (APOS)
Workshop Report,” The National Sscience Fundation Sup-
ported Workshop, Maryland, 2011.
[13] R. E. Bell, F. Ferraccioli, T. T. Creyts, D. Braaten, H.
Corr, I. Das, D. Damaske, N. Frearson, T. Jordan, K.
Rose, M. Studinger and M. Wolovick, “Widespread Per-
sistent Thickening of the East Antarctic Ice Sheet by
Freezing from the Base,” Science Xpress Report, 2011.
[14] M. An, D. A. Wiens, Y. Zhao, M. Feng, A. Nyblade, M.
Kanao, Y. Li, A. Maggi and J.-J. Lévêque, “3D Lithos-
phere Model of the Antarctic Plate from Surface Wave
Observations,” Journal of Geophysical Research, 2013,
in Press.
[15] S. Anandakrishnan, D. E. Voigt, R. B. Alley and M. A.
King, “Ice Stream D Flow Speed Is Strongly Modulated
by the Tide Beneath the Ross Ice Shelf,” Geophysical
Research Letters, Vol. 30, No. 7, 2003.
[16] M. Kanao, A. Maggi, Y. Ishihara, M.-Y. Yamamoto, K.
Nawa, A. Yamada, T. Wilson, T. Himeno, G. Toyokuni,
S. Tsuboi, Y. Tono and K. Anderson, “Interaction on
Seismic Waves between Atmosphere—Ocean—Cryos-
phere and Geosphere in Polar Region,” In: M. Kanao, et
al., Eds., Seismic Waves—Research and Analysis, Rijeka,
Croatia, InTech. Publisher, 2012, pp. 1-20.
[17] R. Aster, “Studying Earth’s Ocean Wave Climate Using
Microseisms,” IRIS Annual Report, 2009, pp. 8-9.
[18] P. D. Bromirski, “Earth Vibrations,” Science, Vol. 324,
No. 5930, 2009, pp. 1026-1027.
[19] E. Stutzmann, M. Schimmel, G. Patau and A. Maggi, “Glo-
bal Climate Imprint on Seismic Noise,” Geochemistry,
Geophysics, Geosystems, Vol. 10, No. 11, 2009, Article
ID: Q11004. doi:10.1029/2009GC002619
[20] M. Grob, A. Maggi and E. Stutzmann, “Observations of
the Seasonality of the Antarctic Microseismic Signal, and
Its Association to Sea Ice Variability,” Geophysical Re-
search Letters, Vol. 38, No. 11, 2011, Article ID: L11302.
[21] Y. Usui, Y. Hiramatsu, M. Furumoto and M. Kanao, “Evi-
dence of Seismic Anisotropy and a Lower Temperature
Condition in the D" Layer Beneath Pacific Antarctic
Ridge in the Antarctic Ocean,” Physics of the Earth and
Planetary Interiors, Vol. 167, No. 3-4, 2008, pp. 205-216.
[22] M. Kanao, “Variations in the Crust Structure of the Lüzow-
Holm Bay region, East Antarctica Using Shear Wave
Velocity,” Tectonophysics, Vol. 270, No. 1-2, 1997, pp.
43-72. doi:10.1016/S0040-1951(96)00207-7
[23] Y. Usui, M. Kanao and A. Kubo, “Upper Mantle Anisot-
ropy from Teleseismic SKS Splitting Beneath Luut-
zow-Holm Bay Region, East Antarctica,” In: A. K. Coo-
per, P. Barrett, H. Stagg, et al., Eds., Antarctica: A Key-
stone in a Changing World, US Geological Survey and
The National Academies, 2007, SGS OF-2007-1047, Short
Research Paper 013.
[24] M. Kanao, A. Fujiwara, H. Miyamachi, S. Toda, M. To-
mura, K. Ito and T. Ikawa, “Reflection Imaging of the
Crust and the Lithospheric Mantle in the Lützow-Holm
Complex, Eastern Dronning Maud Land, Antarctica, De-
rived from the SEAL Transects,” Tectonophysics, Vol.
508, No. 1-4, 2011, pp. 73-84.
[25] T. Isse and I. Nakanishi, “Inner-Core Anisotropy beneath
Australia and Differential Rotation,” Geophysical Journal
International, Vol. 151, No. 1, 2001, pp. 255-263.
[26] G. Toyokuni, H. Takenaka, M. Kanao, D. A. Wiens and
A. A. Nyblade, “Comparison of Global Synthetic Seis-
mograms Calculated Using the Spherical 2.5-D Finite-
Difference Method with Observed Long-Period Wave-
forms including Data from the Intra-Antarctic Region,”
Polar Science, Vol. 6, No. 2, 2012, pp. 155-164.
Copyright © 2013 SciRes. IJG