Update on Italy's SALE Activities

1
3rd SCAR SALE Meeting 6 - 7 June, 2007 Bozeman, MT
Update on Italy's SALE Activities
Carlo Barbante (on behalf of the Italian SALE
community) Department of Environmental
Sciences University of Venice Ca
Foscari Dorsoduro, 2137 30123 Venice, Italy
barbante_at_unive.it
2
Geophysics Ignazio Tabacco, Alessandro Forieri

• FIELD SEASON 2005/06
• 5 flight in DomeC area operated in cooperation
  with BAS and IPEV
• Electromagnetic gravimetric and magnetic
  measurements
• Comparison with previous INGV-IT radar data
• Analysis of the shape of bed reflected echoes
  actually in progress (Genova meeting, 6 June
  2007)
• FIELD SEASON 2006/07
• No activity
• FIELD SEASON 2007/08 (if funded, PNRA meeting in
  June)
• Seismic survey on Concordia Lake (if funded)
• Test of new radar instrumentation in DC area (if
  funded)

G E O P H Y S I C S
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Radar data analysis and geological setting of
DomeC area

• New high resolution map of Concordia Trench/Lake
  area
• Proposed new classification of subglacial lakes
  in Dome C area
• Hypothesis about origin of Trench Lakes, Basin
  Lakes and Relief Lakes of the area
• Comparison between subglacial lakes morphology
  and other lakes on the Earth surface
• Physiography and tectonic setting of the
  subglacial lake district between Vostok and
  Belgica Subglacial Highlands (Antarctica)
• Tabacco I. E., Cianfarra P., Forieri A., Salvini
  F., Zirizotti A.
• Geophysical Journal International, Volume
  165(3), 2006, 1029-1040
• Geological setting of the Concordia Trench-Lake
  system, East Antarctica
• Presented to EGS conference (Wien, April 2007)
• Submitted to Geophysical Journal International

G E O P H Y S I C S
4
Area Dome C-VostokItalian radar exploration
Legend Bed map polar st. Yellow tracks Italian
radar Black tracks new BAS-radar Red spots
subgl. Lakes Green circles Inventory sub. Lakes
G E O P H Y S I C S
(BAS data elaboration are in Progress and are
not yet reported into the map)
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Geophysics Francesco Salvini, Paola Cianfarra
G E O P H Y S I C S
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Subglacial lakes classification in the
Vostok-Dome C district
G E O P H Y S I C S
from Tabacco et al. 2006
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3D GEOMETRY OF THE CONCORDIA FAULT

• NS trending
• Length of at least 180 km
• West dipping
• Constant dip of 60 in the first 20 km of the
  crust then it rotates to 50 at a depth of
  28km. Costant dip of 45 in the deper part of the
  crust (till the base at 34 km)

G E O P H Y S I C S
P. Cianfarra, PhD Thesis
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PROPOSED CENOZOIC AGE
Concordia Trench
G E O P H Y S I C S
Transversal section of the subglacial trough
hosting the southern trench lake as derived from
RES data
The asymmetry is evident and has not been
obliterated by erosional episodes, as well as
secondary river valleys, including periods of wet
ice-bedrock contact of the ice cap. This implies
a reasonable formation age that spans from
immediately prior the ice cap formation (38 Ma,
De Conto Pollard, 2003), as fluvial valleys, to
recent time beneth the dry bedrock-ice cap contact
9
Radio Echo Sounding Baskaradas, Bianchi,
Forieri, Sciacca,Tabacco, Urbini, Zirizzotti,
Zuccheretti
The Radio Echo sounding (RES) research group work
on the improvements of the RES systems. The group
will participate in the RES campaigns of the
Concordia lake zone in Antarctica. Radar surveys
will be performed for the characterization of the
lake Concordia and of its surrounding
environment. In particular the detailed
topography of the lake surface and the
surrounding zones will be realized with new Radar
campaigns with a reduced griding nodes distance
of the survey, which will allow a greater
definition of the lake zone. The study of the
different zones of the lake environment will be
performed by the study of the physical conditions
between the ice/water and ice/bedrock interfaces,
using an electromagnetic analysis of the
different amplitude of the received pulses.
R E S
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Glacio RADAR
R E S
Glacio RADAR is the Italian RES system used for
glaciological measurements. It is an Envelope
RADAR working at 60 MHz with a pulse length
variable from 200 ns to 1µs (vertical resolution
8 to 40 m). The power of the transmitted
signal is 4 kW and the logarithmic receiver has a
100dB of dynamic range. The acquired RADAR
traces are 1280 points, 8 bit at 20MHz of
sampling frequency. The horizontal resolution is
about 8 m.
11
Flight paths during the 1995 2003
The measurements, obtained using the Glacio RADAR
during five Italian Antarctic Expeditions (1995 -
2003), have been used in different frameworks.
Lake, ice tongues, bottom morphology and ice
thickness of shallow and deep regions have been
measured .
R E S
7 lakes path A raw radargram example with
internal layers, bedrock and different lakes.
12
Work in progress
To achieve a better resolution an improvement
like a higher carrier frequency (150 MHz) is
required. This will force the use of a new
antenna system with a better electromagnetic and
aerodynamic characteristics with narrow beam.
Also, the sampling frequency will be modified
(100MHz) to increase the definition of the trace
and the vertical resolution of the instrument.A
new antenna array and a new phase coded RADAR
have been developed and will be tested in the
next Italian Antarctic campaign (2007). New
Coded RADAR The new RADAR is a 13 bit Barker
code 150 ns sub-pulse, 1.95 µs total pulse
length, with a better vertical resolution ( 6 m)
and signal sensibility.
R E S
New antenna system
The new antenna system has 4 folded dipoles fed
with a phasing harness for each side. One side
used for Tx and the other for Rx. The antennas
are fed in phase, the harness is a single feed
point with the splitters in line.
13
Seismic Daniel Nieto Yabar, Riccardo Geletti,
Stefano Picotti
In order to understand the geological context of
subglacial lakes (i.e. their relation to basement
structures, internal configuration of the
sediments, sedimentary processes, and occurrence
of free gas or hydrated gas layers) it is
essential that an adequate coverage of
conventional multichannel seismic reflection
profiles is acquired over and around the lake,
possibly in a grid geometry. The seismic
acquisition test phase of the project was
performed at the completion of the modelling
study. The main objective of the plan in December
2003 was to verify the seismic method
applicability for the identification of
subglacial structures in the Eastern Antarctica.
The designated champion area is the zone close to
base Dome C. This area represents a type site as
far as glacial stratigraphy of interest for the
prospecting of subglacial lakes and the base
supply the logistic facility.
S E I S M I C
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THE ELASTIC SIMULATION
Shot
I-W reflected P wave
S E I S M I C
I-W converted S wave
directed S wave
W-S reflected P wave
S-B reflected P wave
Depth (m)
Ice
Water
Sediments
Bedrock
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Seismic Recording System
Recording stations
Geophones
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DRILLING THE HOLE AND CHARGING THE SHOTPOINT WITH
DYNAMITE
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THE SEISMIC TEST AT DOME C
S E I S M I C
The processed seismic data recorded in the test
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Set up of clean technologies for sub-sampling and
decontamination of meteoric and accreted ice from
drilling sites on sub-glacial lakesTrace
Element and Rare Earth Element in deep accreted
ice from Vostok, Antarctica implications for the
origin of the subglacial lake
Chemistry Carlo Barbante, Paolo Gabrielli,
Vania Gaspari, Rita Traversi, Roberto Udisti
C H E M I ST R R Y
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Decontamination devices
MELTER ice samples Continuous analysis (CFA,
FIC, ICP-MS) Collection of discrete samples
C H E M I ST R R Y
DIPPING ice samples Discontinuous analysis
(ICP-MS)
CHIESELLING ice samples Discontinuous
analysis (ICP-MS)
MICROSCRAPER firn or ice strips
discontinuous samples
20
ICE CORE MELTER
C H E M I ST R R Y
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Decontamination by MELTER
Cl-
Na
External layer
C H E M I ST R R Y
Inner part
NH4
Ca2
MSA
SO42-
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MICROSCRAPER
C H E M I ST R R Y
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Decontamination by SCRAPER
Na
Cl-
C H E M I ST R R Y
NH4
Ca2
MSA
SO42-
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Decontamination

• The outer layers show higher concentration levels
  for Na, Cl-, Ca2 and NH4 samples
  decontaminated by micro-scraper with respect to
  melter whereas the inner layers show similar
  concentration levels suggesting that the handling
  with the micro-scraper leads to a contamination
  of the superficial layers but this is not
  transferred to the inner core.
• SO42- and MSA concentrations are roughly the same
  for samples obtained both by micro-scraper and
  melter. Such a result cant be ascribed to
  contamination but to a slightly inhomogeneous
  layers in the ice core.
• Quite good results for Trace Elements as well

C H E M I ST R R Y
R. Traversi, S. Becagli, E. Castellano, A.
Morganti, M. Severi, R. Udisti. Set up of clean
technologies for sub-sampling and decontamination
of meteoric and accreted ice from drilling sites
on sub-glacial lakes. Terra Antartica Reports in
press.
25
Trace Elements in the accreted ice of Vostok Lake
C H E M I ST R R Y
Samples available for trace and rare earth
elements determination in the deepest part of
the Vostok ice core
26
Rare Earth Elements
C H E M I ST R R Y
Lowest REE concentrations in the accreted ice
type II
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Rare Earth Elements
C H E M I ST R R Y
High variability of Ce anomaly in the accreted ice
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Rare Earth Elements
C H E M I ST R R Y
Different REE patterns in the accreted ice with
respect to atmospheric ice
29
Rare Earth Elements
C H E M I ST R R Y
Inhomogeneous REE patterns in the accreted ice
even within the same ice section (different
sub-samples)
30
Biology Cinzia Verde, Guido Di Prisco, Daniela
Giordano, Giulia Barbiero, Roberta Russo
B I O L O G Y

• Aims of the project
• analysing microbial biodiversity
• b) developing the study of PhTAC125 genome,
  focusing on the biological
• processes potentially related to cold
  adaptation
• c) exploiting the biotechnological potential of
  Antarctic bacteria
• d) studying the structural and functional
  properties of cold-adapted
• truncated hemoglobins and flavohemoglobins,
  and their potential role
• in biotechnological processes, considering
  their ability in improving cell
• growth, heterologous protein expression and
  oxidative catalytic processes

31
Pseudoalteromonas haloplanktis TAC125 the first
available Antarctic bacterial genome completely
sequenced and annotated
Pseudoalteromonas haloplanktis TAC125 (PhTAC125)
is a psychrophilic bacterium isolated in
Antarctic coastal sea water, in the vicinity of
the French station Dumont dUrville, Terre
Adélie, permanently thriving at temperatures
close to the freezing point
B I O L O G Y
The recent publication of the PhTAC125 genome
sequence and annotation (Médigue et al. 2005)
provides a unique opportunity to explore the
cellular strategies adopted by cold-adapted
bacteria to cope with the cold.
32
Results
Structure-based sequence alignments and
phylogenetic analysis have shown that the
TAC125 genome contains two TrHb genes belonging
to Group II and another one belonging to Group
I
B I O L O G Y

• Gene coding a Group II-trHb ? cloned and
  over-expressed in E. coli
• Recombinant protein ? purified

SDS-PAGE of Ph-trHb

• Structural characterisation ? carried out by
  absorption
• spectroscopy and circular dichroism

Absorption spectra of Fe3-trHb (dotted line),
Fe2-trHb (solid line)

• Evolutionary characterisation, carried out by
  molecular phylogeny, to predict
• which residues are responsible for functional
  divergence between members
• of the globin family. Residues may have
  different functional constraints,
• and their substitution rate varies among the
  sites

Giordano et al. Gene 2007
33
The entire seismic acquisition system was
developed and ad hoc built by the OGS in
cooperation with the Solgeo S.r.l. geophysical
I0,talian company. The instruments was performed
to work in extreme climatic condition (very low
temperature) for example the geophone was tested
until - 60 C in a laboratory freezer. The
seismic acquisition system is composed of five
independent remote acquisition units with three
channels of each, a trigger unit and one
exploder. The source used in the test survey
was the explosive charges with different feature.
Finally, in this phase of the plan, it is to
verify the correct operation of the recording
system, the acquisition parameters in base to the
theoretical models and the quality of the
obtainable data using different types of sources,
depth holes and geometries of acquisition.
Another goal was to verify possible logistic
problem in this extreme climatic conditions.
Seismic test at Dome C (Austral summer 2003)
S E I S M I C
34
The PhTAC125 genome contains three genes coding
truncated hemoglobins (trHbs) and one gene
encoding a flavohemoglobin (flavoHb)
TrHbs have the same basic topology of higher
vertebrate Hbs, usually associated with the
utilisation of oxygen. They display functions
other than the typical one of binding di-atomic
ligands even if their physiological and
biochemical functions are not well defined as
yet. The very high oxygen affinity displayed by
most bacterial globins points to a preferential
role as oxygen scavenging rather than as oxygen
transporter.
B I O L O G Y
FlavoHbs, i.e. chimeric Hbs containing a
C-terminal redox-active domain with binding sites
for NAD(P)H and FAD, are widely viewed as nitric
oxide (NO)-detoxifying enzymes by means of an
aerobic reaction which uses oxygen and NAD(P)H to
form nitrate. This general role in NO defense is
of great interest for clinical microbiology
because flavoHbs may represent a novel therapy.