In the frame of glaciology and palaeoclimate research, Talos Dome (72°48lS; 159°06lE), an ice dome on the East
Antarctic plateau, represents the new selected site for a new deep ice core drilling. The increasing interest in this region
is due to the fact that the ice accumulation is higher here than in other domes in East Antarctica. A new deep
drilling in this site could give important information about the climate changes near the coast. Previous papers
showed that the dome summit is situated above a sloped bedrock. A new position on a relatively flat bedrock 5-6 km
far from here in the SE direction was defined as a possible new ice core site for an European (Italy, France, Swiss
and United Kingdom) drilling project named as TALDICE (TALos Dome Ice Core Project). This point, named as
ID1 (159°11l00mE; 72°49l40mS), became the centre of the Radio Echo Sounding (RES) flight plan during the 2003
Italian Antarctic expedition, with the aim of confirming the new drilling site choice. In this paper 2001 and 2003 RES
data sets have been used to draw a better resolution of ice thickness, bottom morphology and internal layering of a
restricted area around the dome. Based on the final results, point ID1 has been confirmed as the new coring site. Finally,
the preliminary operations about the installation of the summer ice core camp (TALDICE) at ID1 site carried
out during the XX Italian Antarctic expedition (November 2004-December 2005) are briefly described

Bianchi, C.

Cafarella, L.

Frezzotti, M.

Tabacco, I.

Urbini, S.

Zirizzotti, A.

Earth-prints Repository

1133
ANNALS  OF  GEOPHYSICS, VOL.  49, N.  4/5, August/October  2006
Mailing address: Dr. Stefano Urbini, Istituto Naziona-
le di Geofisica e Vulcanologia, Via di Vigna Murata 605,
00143 Roma, Italy; e-mail: urbinis@ingv.it
Key  words radio echo sounding – radio glaciology
– ice thickness measurements – internal layering
1. Introduction
Talos Dome is an ice dome at 72°48lS;
159°06lE on the edge of the East Antarctic
plateau adjacent to the Victoria Land mountain
about 290 km from the Southern Ocean and 250
km from the Ross Sea. This site has a good geo-
chemical and palaeoclimate record preserved in
the ice, because the accumulation (80 kg m−2 a−1)
is higher here than at other domes in East Antarc-
tica. Moreover, according to the thickness/snow
accumulation ratio, a 120-150 thousand years
(BP) palaeoclimatologic history is expected (De-
ponti and Maggi, 2003). For this reasons Talos
Dome, from previous studies (Frezzotti et al.,
2003), was selected as new drilling site in order
to study the response of near-coastal sites to cli-
mate change and Holocene history of accumula-
tion rates in the Ross Sea region. The knowledge
of bedrock topography of Talos Dome region
and its internal layering are of great importance,
not only for the obvious reason of knowing how
deep to drill, but also because the lower part of
deep ice cores can only be dated by modelling
studies (Reeh et al., 1985).
In this paper, a reconstruction of ice thick-
ness, bedrock morphology and some internal
layers has been made by Radio Echo Sounding
Location of a new ice core site 
at Talos Dome (East Antarctica)
Stefano Urbini (1), Lili Cafarella (1), Achille Zirizzotti (1), Cesidio Bianchi (1),
Ignazio Tabacco (2) and Massimo Frezzotti (3)
(1) Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
(2) Dipartimento di Scienze della Terra «Ardito Desio», Sezione Geofisica,
Università degli Studi di Milano, Italy
(3) ENEA - CRE Casaccia, S. Maria di Galeria (RM), Italy
Abstract
In the frame of glaciology and palaeoclimate research, Talos Dome (72°48lS; 159°06lE), an ice dome on the East
Antarctic plateau, represents the new selected site for a new deep ice core drilling. The increasing interest in this re-
gion is due to the fact that the ice accumulation is higher here than in other domes in East Antarctica. A new deep
drilling in this site could give important information about the climate changes near the coast. Previous papers
showed that the dome summit is situated above a sloped bedrock. A new position on a relatively flat bedrock 5-6 km
far from here in the SE direction was defined as a possible new ice core site for an European (Italy, France, Swiss
and United Kingdom) drilling project named as TALDICE (TALos Dome Ice Core Project). This point, named as
ID1 (159°11l00mE; 72°49l40mS), became the centre of the Radio Echo Sounding (RES) flight plan during the 2003
Italian Antarctic expedition, with the aim of confirming the new drilling site choice. In this paper 2001 and 2003 RES
data sets have been used to draw a better resolution of ice thickness, bottom morphology and internal layering of a
restricted area around the dome. Based on the final results, point ID1 has been confirmed as the new coring site. Fi-
nally, the preliminary operations about the installation of the summer ice core camp (TALDICE) at ID1 site carried
out during the XX Italian Antarctic expedition (November 2004-December 2005) are briefly described. 
1134
Stefano Urbini, Lili Cafarella, Achille Zirizzotti, Cesidio Bianchi, Ignazio Tabacco and Massimo Frezzotti 
data analysis. RES system is an active remote-
sensing method based on the generation, propa-
gation and reflection of an electromagnetic wave
due to one or more discontinuities in the media
dielectric properties (Bogorodsky et al., 1985).
This work reports the results obtained by
the integration of the last two Antarctic cam-
paigns (2001 and 2003) focused on the selec-
tion of the Talos Dome best drilling site posi-
tion. The 2003 survey was planned to achieve a
more detailed information in the area close to
the topographic summit of Talos Dome. 
2. Field data acquisition and analysis
Since 1997 the Istituto Nazionale di Geofisi-
ca e Vulcanologia (INGV) and University of Mi-
lan have been developing their own airborne ra-
dio echo sounding system for remote-sensing
studies of the polar ice sheet and glaciers in
Antarctica (for details see Tabacco et al., 1999).
This system (named INGV-IT, Tabacco et al.,
2002) has been used to map ice thickness and in-
ternal layers of glaciers, ice sheets and ice shelves
(Tabacco et al., 1998, 2000; Capra et al., 2000;
Frezzotti et al., 2000; Remy and Tabacco, 2000;
Bianchi et al., 2001; Siegert et al., 2001). 
The RES system has been slightly modified
during each expedition. Main radar system im-
provements have been applied between 1996
and 2001 concerning the total range time
(which increased from 51.2 µm to 64 µm), the
number of samples for each radar track (en-
hanced from 1024 to 1280 samples) and the
number of acquired tracks per second (raised
from 0.3 track s−1 to 10 tracks s−1). 
Figure 1 shows the aircraft legs along which
the measurements have been recorded during
2001 and 2003 expeditions (black and red lines
respectively) in UTM coordinates WGS84.
About 18% of data could not be used due to the
Fig. 1. Aircraft legs covered during 2001 and 2003 Italian Antarctic RES expeditions (black and light grey lines
respectively). The position of the selected drilling site is indicated as ID1.
Location of a new ice core site at Talos Dome (East Antarctica)
lack of returned echoes from the bedrock but,
on the whole, results can be considered good. In
fig. 1 flight lines are interrupted where the
bedrock reflection signal has not been received. 
The first data set (2001) did not permit the
detecting of regular and continuous internal
layers especially in the dome area. The techni-
cal improvements introduced in the 2003 RES
instrumentation allowed to identify three re-
flecting horizons characterized by good regu-
larity and continuity.
RES raw data post-processing flow consisted
basically in deconvolution, gain adjustment, ver-
tical and horizontal filtering, data stacking and, in
some cases, migration. All data were processed
following the same criteria and finally were
cross-checked. Crossover point analysis pointed
out that ice thickness values in different RES pro-
files are in good agreement. Indeed, counted
cross points on all legs were 59: 30% of cross
points exceed a distance greater than 200 m and
about 51% have a difference in ice thickness less
than 40 m. Ice thickness was calculated using a
constant velocity of 168 m µs−1 (Glen and Paren,
1975; Bogorodsky et al., 1985) while spatial res-
olution was around 1 scan/7 m.
After the described preliminary analysis the
same processing parameters (and not the pro-
cessing flow) have been changed for a better
layering resolution. 
Whole 2001 and 2003 RES data sets have
been used to model the three-dimensional view
of the bedrock topography and of the internal
layering. The investigated region covers an area
of about 1400 km2. All thickness profiles data
sets have been gridded by Kriging method with
a square grid cell size of about 500 m. 
A preliminary RES data analysis pointed
out that Talos Dome is a mountainous area with
a rough morphology as the neighbouring Fron-
tier Mountains region. Moreover, the RES sur-
vey of the investigated area did not show evi-
dences of subglacial lakes or basal melting.  
3. Drilling site characteristics
It is known that a good drilling site has to be
characterized by a relatively flat condition of
both the bedrock and the main internal layering.
In fact, an accurate time-depth core correlation
is possible only where regular and horizontal
snow layering occurs. Moreover, in this area,
snow radar and GPS surveys show that the shal-
low (100 m) internal layering is continuous and
horizontal up to 15 km from the summit (Frez-
zotti et al., 2004).
Figure 2 shows the ice surface and sub-gla-
cial topography of the Talos Dome region. A de-
tailed surface elevation map was made using da-
ta from many GPS altimeter surveys. The geo-
graphic position of Talos Dome, located at Long
159°04lE and Lat 72°46lS (Frezzotti et al.,
1998, 2003) is indicated in the figure by a trian-
gle symbol. The bedrock depths have been re-
ferred to the accurate elevation model obtained
using the altimetric measurements for the whole
investigated area. As shown, the bedrock topog-
raphy consists of a deep basin where the ice
thickness ranges from 800 to 2900 m. The deep
basin is connected to a low bedrock zone. In
particular, bedrock of the Talos Dome Summit
(TDS) is about 440 m in elevation (WGS84) and
it is covered by about 1900 m of ice. The dome
summit is situated above a sloped bedrock over
a kind of isolated ridge and for this reason it is
not the ideal drilling site. Following the main
ridge structure (elongated to SE direction) 5-6
km far from this point, bedrock became relative-
ly flat and it is characterized by an elevation of
about 750 m (WGS84) covered by 1550 m of
ice (Frezzotti et al., 2003). This point, named
ID1 (159°11l00mE; 72°49l40mS indicated as a
black square in the figures 1 and 2) was the cen-
tre of the 2003 RES flight plan. Previous cam-
paign data analysis showed also the presence of
internal layering below the dome, but reflecting
horizons were irregular and discontinuous. By a
focused data post processing, 2003 RES dataset
allowed to detect three internal layers (L1=1850
m; L2=1690 m; L3=1240 m (WGS84)) charac-
terized by a good continuity along the profiles. 
Mountain and valley morphologies orienta-
tion follows the ice-divide line (NW-SE) and
clearly influence the dome and the internal lay-
ers stratigraphy. 
The new more detailed 3D maps carried out
by 2001-2003 RES datasets integration, also
supported by new internal layering analysis
(fig. 3), confirm that the position of point ID1
1135
1136
Stefano Urbini, Lili Cafarella, Achille Zirizzotti, Cesidio Bianchi, Ignazio Tabacco and Massimo Frezzotti 
Fi
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Location of a new ice core site at Talos Dome (East Antarctica)
can be considered a good choice for a new deep
ice drilling.
Based on the above considerations, during
the XX Italian Antarctic expedition (austral
summer 2004-2005), some preliminary works
were carried out in order to start the drilling op-
erations. Once localized ID1 point, a wide
trench (50×5.5 m) was excavated by a Pisten
Bully in order to contain all drilling instrumen-
tations. Coring operations started, reaching the
depth of about 128 m. The coring project plan
(TALDICE) foresees the end of the drilling op-
erations in the next two austral summer cam-
paign. 
5. Conclusions
Talos Dome is an ice dome on the Antarctic
plateau 250 km from the Ross Sea and about
290 km from the Southern Ocean. It was select-
ed as new drilling site to study the response of
near-coastal sites to climate change. Frezzotti
et al. (2003) showed that the dome summit was
not the ideal drilling site because it is situated
above a sloped bedrock and they defined a new
point on a relatively flat bedrock, 5-6 km more
to the SE. This point, named ID1 was deeply in-
vestigated during 2003 Italian Antarctic RES
survey. 
The integrated 2001 and 2003 RES data sets
allowed a better resolution of ice thickness, bot-
tom morphology and some internal layering of
a restricted area around the dome, in order to
confirm ID1 as the new drilling site. Datasets
were collected by airborne INGV-IT radar and
cover an area of about 1400 km2 around the
dome. This paper shows the bedrock of the in-
vestigated region in two and three-dimensional
maps. Moreover, ice surface topography de-
fined by GPS altimeter has been reported to
have a more complete view of the region. Data
analysis confirmed that Talos Dome summit
was an inadequate drilling site. On the other
hand, ID1 site was localized on the top of a
buried mountain ridge where both bedrock and
internal layering showed a flat and regular
trend. Considering that snow radar and GPS
surveys (conducted on the Talos Dome area)
showed that the shallow (100 m) internal layer-
ing is continuous and horizontal up to 15 km
from the summit (Frezzotti et al., 2003), the re-
sults carried out by the 2001-2003 RES data in-
tegration confirmed ID1 position as a potential
optimal drilling site. 
These results were used during the last XX
Italian Antarctic campaign (austral summer
2004-2005), in which some preliminary work
was carried out to start the new drilling opera-
tions. Coring operations started, reaching the
depth of about 128 m. The coring project plan
(TALDICE) foresees the end of the drilling op-
erations in the next two austral summer cam-
paigns. 
Acknowledgements
Research was carried out in the framework of
the Project on Glaciology and Paleoclimatology
of the Italian PNRA National Antarctic Program.
Authors wish to thank the anonymous reviewers
for their critical and useful observations.
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(received March 12, 2006;
accepted September 20, 2006)


Location of a new ice core site at Talos Dome (East Antarctica)

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Location of a new ice core site at Talos Dome (East Antarctica)

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