Each of the five working groups was tasked with developing
scientific goals for a program, justifying the program, developing a
strategy and time-line to accomplish the goals, and justifying why
Lake Vostok is the preferred study site.
GEOCHEMISTRY WORKING GROUP CONCLUSIONS
Group Members: Mahlon C. Kennicutt II (archivist), Todd Sowers,
Berry Lyons, Jean Robert Petit
JUSTIFICATION FOR LAKE VOSTOK STUDIES
Due to the remote location and the complexity and cost of the
logistics to mount a study of subglacial lakes, it is imperative
that the scientific return from such a study be justified in light
of the resources needed to accomplish the program.
In particular, it
is important to elucidate what it is that makes subglacial lakes a
high priority for study, and in particular why Lake Vostok is the
preferred site amongst all other possible sites.
On the first issue,
the “extreme” environment under which the lakes exist suggests that
fundamental questions related to an array of scientific issues could
be addressed by an interdisciplinary study of subglacial lakes. Life
at the extremes is justified in the context of the ongoing LExEn
program. From a geochemical standpoint, the subglacial lake systems
represent an unique and unparalleled combination of physical and
The lakes are unique in the low temperatures
and high pressures encountered, the total darkness, the origins of
the water in the system (suspected to be fresh), the overlying
thickness of ice, and their isolation from the atmosphere for long
periods of time. It is hypothesized that this combination of
attributes will lead to an unique geochemical system that is
duplicated under few, if any other, circumstances world-wide.
individual attributes can be found in various locations (dark, cold,
and high pressure in the deep sea) the combination of traits
described above is only found in subglacial lakes.
Amongst subglacial lakes, the most obvious characteristic of Lake
Vostok that differentiates it from the 60 to 80 other known lakes,
is its size. Lake Vostok is believed to be the largest subglacial
lake on the Antarctic continent. The size of the lake imparts
attributes that make it well-suited for an initial study of
The size of the lake suggests that Lake Vostok is
the most likely site for a fully developed subglacial lake system
that might be precluded in other smaller lakes. The varying water
depths, the varying and substantial sediment accumulations, the
varying thickness of the overlying ice sheet, and the sheer size of
the lake suggests that the likelihood of physical and chemical
gradients within the lake is high.
The physical setting suggests
that circulation, stratification, and compartmentalization within
the lake is likely.
This setting is believed to be the most
favorable for supporting a fully developed subglacial lake system
and provides the greatest likelihood that biological systems have
inoculated and developed within the lake.
GOALS FOR GEOCHEMICAL INVESTIGATIONS
1) The first and foremost goal of any geochemical investigations
would be to characterize the
structure of the lake’s water column. Due to the low temperatures
and high pressures it is believed
that hydrates of various gases will play an important role in
determining the distribution of the
lake’s geochemical properties. Stratification of the lake in very
unusual ways may occur due to
density differences between various gas hydrates, some heavier than
water and some lighter, and
the suspected cycles of thawing and freezing that appear to
characterize different regions of the
lake. In a more standard sense, initial studies of the lake would
establish the limnological characteristics of the lake both
vertically and horizontally including, for example, the
distributions of salinity, temperature, major ions, and nutrients.
2) As a follow on to the discussion of hydrates, the gaseous
constituents of the lake would also be a high priority for
investigation. The physical occurrence of gaseous constituents and
the partitioning between free, dissolved and hydrate phases will be
important to establish. The origins of these gases should also be
explored through the use of stable isotopic analysis of various key
elements. It would also be important early in the study of the lakes
to determine the distribution of those geochemical properties most
directly affected by the presence of biota, in particular microbiota.
These properties include, but are not limited to: redox potential,
pH, sulfate reduction, methanogenesis, metal and nutrient
3) Due to the emphasis on the theme of life in extreme environments,
the carbon cycle would be an area of special emphasis for
geochemical investigations. The system is expected to be unique in
that cold water carbonates and hydrates of hydrocarbon gases may be
important reservoirs of carbon. The carbonic acid system may also be
unusual at the ambient high pressures and low temperatures. The
origins and cycling of organic carbon in the lakes will also be of
special interest. The distribution between dissolved and particulate
organic carbon and the portions of the pools that are biologically
available will be important considerations. The reservoir of carbon
in sediments may also be important for sustaining any extant
4) Finally, the interaction between the geochemical properties of
the lake and the circulation within the lake will be important to
characterize. Redistribution of chemicals in the lake and the
development and location of physical and chemical gradients may be
important in developing and sustaining biological systems.
JUSTIFICATION FOR GEOCHEMICAL INVESTIGATIONS
Geochemical investigations of subglacial lakes are critical to
interdisciplinary studies to determine the origins and functioning
of subglacial lake systems.
Geochemical properties are widely
recognized as evidence of the presence of life in systems. It can be
argued that some of the more easily measured attributes of a system
that provides evidence of biological processes are geochemical
distributions and patterns.
Biological processes are known to
produce and consume various compounds in the process of living and
surviving in aquatic systems. The water and the sediments of the
lake are also a repository of chemicals derived from various
interactions over the lifetime of the lake. As such, geochemical
distributions and patterns are keys to understanding the origins of
various lake constituents.
As previously mentioned, subglacial lakes
also represent geochemistry at the extremes of temperature,
pressure, light, and isolation suggesting that the study of these
lakes will provide insight into geochemical systems in general.
Areas of particular interest where geochemical investigations will
be key in providing information are the age of the lake and the
origin of the water.
The sedimentary record is an important repository of evidence of the
history and evolution of the lake. Organic and inorganic geochemical
markers of the lake’s history may be deposited and preserved in the
sedimentary record. Geochemical investigations are fundamental to
addressing a wide range of interdisciplinary questions related to
the evolution and history of subglacial lakes as well as documenting
the functioning of these unique systems.
STRATEGY TO MEET GEOCHEMICAL GOALS
Most of the investigations that are important for the geochemistry
component of an
interdisciplinary study of subglacial lakes rely on standard and
it is proposed that the first entry into the lake will be in a
non-sample retrieval mode, appropriate
sensors for measuring geochemical attributes of the water column
need to be developed.
As mentioned above, inferences related to the
presence of life can be obtained by measuring specific geochemical
characteristics of the lake. Initial establishment of the water
column structure and heterogeneity will require real-time in situ
detection of geochemical properties.
Once the investigations have proceeded to sample retrieval, the
methods to be used are readily available and proven. In order to
optimize the information return from geochemical investigations,
water column profiles at multiple locations will be necessary. Time
series measurements will also be important to determine if the lake
is static or dynamic on short timeframes (< 1 yr).
A range of
technologies including continuous measuring sensors left in place,
profiling sensors, and discrete samples will be required to address
the goals of the geochemical investigations.
Geochemical investigations will be key to an interdisciplinary study
of subglacial lakes.
A range of characterization activities would be
an initial goal including water column structure, the distribution
and occurrence of gaseous components, the reservoirs and cycling of
carbon, and the biogeochemical processes operating in the lake.
vertical and horizontal distribution of essential chemicals in the
lake will reflect interactions with lake circulation and the
alteration of these patterns by organisms. Geochemical measurements
will be key in determining the age, the origins of various
constituents, the history, and the evolution of the lake.
technologies are currently available but development of remote
sensors of geochemical properties will be needed. It is estimated
that one to three years will be needed to develop these new
BIODIVERSITY WORKING GROUP CONCLUSIONS
Cynan Ellis-Evans (archivist)
José de la Torre
JUSTIFICATION FOR LAKE VOSTOK STUDIES
The compelling science justification for undertaking research at
Lake Vostok is:
1)the unique nature of the
environment - permanently cold, dark, high pressure
2)this lake may lie within a
rift valley of as yet undetermined age or activity - this
offers the potential for geothermal processes comparable to
the hydrothermal vents of the ocean abyss
3)the spatial scale of the
environment - the lake is amongst the top 10 largest lakes
worldwide and offers an opportunity to research large scale
4)the temporal scale of the
environment - the possibility exists that the lake overlies
sediments of an earlier rift valley lake, providing a
5)information on possible inoculum
is available - it is likely to be representative of other
sub-glacial lakes but the Vostok ice core has a detailed
record for the overlying ice sheet of biota present within
that ice sheet
6)the first opportunity to sample a microbial community isolated
from the atmosphere for
perhaps a million years or more - possibly uncovering novel
processes, notably the microbiology of gas clathrates
(hydrates) in a water column
7)possible data on evolution of global biota - data gathered could
potentially contribute to the current debate regarding the evolution
of global biota.
GOAL FOR BIODIVERSITY STUDIES
Extreme environments have proved a rich source of novel
physiological processes and biodiversity.
The estimated age of this
lake and its isolation from the atmosphere for possibly a million
years, may allow the identification and study of novel
micro-organisms or processes, notably the microbiology of gas clathrates (hydrates) in a water column.
The goal of the
biodiversity studies should be to establish the structure and
functional diversity of Lake Vostok biota.
JUSTIFICATION FOR BIODIVERSITY STUDIES
Microorganisms are a substantial component of all environments and
their significant role in key food web processes is recognized
increasingly. The main lineages of life are dominated by microbial
forms, and comparative analyses of molecular sequences indicate that
all life belongs to one of three domains, Bacteria, Archaea and
Microbes are ubiquitous in extreme environments.
deep ocean hydrothermal vent studies suggest that such environments
may have been sites for the origin of life. Novel environments, such
as sub-glacial lakes, may likewise contain unique biota.
STRATEGY FOR BIODIVERSITY STUDIES
At least four biodiversity
scenarios exist for the lake:
1)The lake is geologically inactive and only contains till,
glacially derived sediments with
low organic carbon. No geothermal hot spots exist, and the low
organic carbon till,
substantially dilutes any input of ice sheet biota. Gas clathrates
present in the lake are a
potential target for microbial activity.
2)The lake is geologically inactive with old lake sediments buried
under recent till. The
clathrates are still a target, but retrieval of old lake sediments
is a further goal.
3)The lake is geologically active without old lake sediments. The
sites of geothermal
activity would be a major focus requiring several coring sites.
4)The lake is geologically active and old lake sediments are
present. This would be the
best case scenario, offering a range of research topics, requiring
long cores and possibly
multiple sampling sites.
In the absence of detailed data on the lake characteristics this
group suggests that the initial starting point for sampling the lake
should be in the melting zone of the lake and not the accretion
The melt zone will be where the clathrates and ice sheet
microflora enter the lake.
Both the ice/water interface region and
the sediments offer the best opportunity for initially looking for
microbes, but it was recognized that clathrates may be distributed
through the water column. The accretion zone will not be a source
for microbial or clathrate input to the lake.
In light of these four scenarios, the strategy for studying
biodiversity in Lake Vostok would involve (a) preliminary activities
prior to any field sampling (zero-order activities) to establish the
nature of the environment, possible microfloral inputs and relevant
technologies and (b) field sampling of Lake Vostok and post-sampling
(a) ZERO-ORDER ACTIVITIES -(no field campaign needed)
1 - Physical characterization of the lake (non-invasive)
2 - Technological developments for in situ micro- and macro- scale
retrieval, non-contamination of lake and data relay from within
lake. Remote operated
vehicle (ROV) to increase the area of lake studied
3 - Development of biogeochemical and ecosystem models
4 - Characterization of the ice sheet microflora using existing
cores if possible and both
molecular and cultural methodologies
(B) MAIN SAMPLING ACTIVITIES -(Field campaign needed)
1 - Obtain vertical profiles of physical and chemical parameters
from the ice/water interface through to sediments. Microscale
profiles within surface sediments
2 - Leave monitoring observatories
in place with both physical/chemical monitoring and a bio-sensing
capability, for detecting life in dilute environments needing long
3 - Sample retrieval (for chemical and biological
purposes) from the ice/water interface, from the water body (may
need to filter large volumes to concentrate biota) and from
sediments - A suite of molecular, microscopical and activity
measurements (see earlier overview by Jim Tiedje) will be required
to analyze potential biota. Anti-contamination protocols will
feature significantly here (see earlier overview by White/Kern).
May need to consider repeat sampling or further sites, notably if
there are geothermal hot spots. Also need to take into account
possible heterogeneity, particularly in sediments. An ROV may offer
an ability to sample heterogeneity more cheaply than numerous drill
TIME FRAME FOR BIODIVERSITY STUDIES
Zero order activities - 2-3 years in advance of lake penetration,
but continuing afterwards, notably with modeling studies
Year 1 - Vertical profiling and establishment of long term in situ
Years 2 and 3 - Sample retrieval activities at one or more sites
Year 4 - Sample analysis ongoing and further planning
Year 5 and 6 - New research initiatives building on data collected
to date - could include tackling issues of heterogeneity or perhaps
novel biogeochemical processes
Note 1: The merits of sampling
another lake in the vicinity of Lake Vostok need to be considered.
Note 2: The Year 1 work might be best undertaken with the NASA
strategy of using both a hot water drill* and a modified Philberth
probe** to penetrate the lake, deployment of hydrobots beneath the
ice and at the sediments and establishment of observatories in the
lake. Subsequent years could potentially use alternative drilling
technologies to facilitate sample retrieval, once contamination
issues have been addressed.
* A hot water drill pushes hot water down a hole to melt the ice.
**A Philberth probe is an instrumented cylindrical shaped device
that has an electrical heater at its tip. The melting of ice ahead
of the probe allows it to drop down through the ice under its own
weight paying out cable to the surface as it goes. A device such as
this is being proposed as a means of getting through the last 100 m
or so of overlying ice sheet. (For more information on this please
refer to Appendix (1) “Why Lake Vostok?” write up by Stephen Platt
SEDIMENTS WORKING GROUP CONCLUSIONS
Peter T. Doran (archivist)
JUSTIFICATION FOR LAKE VOSTOK STUDIES
The existing ice core from Lake Vostok can provide us with unique
background information on the Lake which is not available to us from
any other subglacial lakes in Antarctica. The size and estimated age
of the lake offers the best potential for a long continuous
GOALS FOR SEDIMENT STUDIES
The sediments of Antarctic subglacial lakes have the potential to be
significant for the following reasons:
1. Extant microbial communities. Microbial communities often favor
interfaces as habitats, so that the ice/water and sediment/water
interfaces will be prime targets in the search for life. Along with
sediment deposition at the bottom of the lake, chemical energy
required by the microbes may be focused on the bottom, i.e., if
geothermal energy flux is significant in this habitat.
the search for extant life in Lake Vostok should not end at the
sediment/water interface, but should extend into the sediment
column. Measurements of chemical profiles (including dissolved,
particulate and gas phases) in the sediment can also be used for
life detection (past and present) and for mapping of metabolic
2. Storehouse of paleoenvironmental information. The sediment column
in Lake Vostok has been estimated to be ~300 m. This thickness of
sediment could contain an unparalleled record of Antarctic
paleoenvironmental information, extending beyond the limit of ice
core records. The record contained in the sediments may reveal
information on past geochemical processes, microbial communities,
and paleoclimate. Interpretation of this record will require a
thorough understanding of the modern lake depositional environment.
The gas geochemistry in Lake Vostok has the potential to be unique,
with hydrated gas layers accumulating in the water column based on
density stratification. In particular, CO2 hydrates are expected to
sink upon entering the water column and collect in the bottom
sediments, potentially creating a continuous record of atmospheric
CO2 in the lake sediments.
3. Direct measurement of geothermal heat flow. Any sediment borehole
created can be used to determine geothermal heat flux through direct
temperature measurements. This information will contribute to models
of the lake’s origin, possible circulation and maintenance.
Extraterrestrial material capture. The lake sediments undoubtedly
contain a large number of meteorites, micrometeorites and cosmic
dust (e.g. interplanetary dust particles and cometary debris) given
that all “coarse” material that moves into the lake and melts out of
the ice will be focused in the sediments. In this way the sediments
offer an extraordinary opportunity to measure extraterrestrial flux
over possibly several million years.
The flux of extraterrestrial
material can be monitored by measuring helium-3 in very small grains
(<50 µm) in bulk sediments. In fact, it has been suggested that
periodic changes in the accretion rate of extraterrestrial material
is due to a previously unrecognized 100,000 yr periodicity in the
Earth’s orbital inclination which may account for the prominence of
this frequency in the climate record over the past million years.
Measurements of the extraterrestrial flux of material to the Vostok
sedimentary record coupled with the possible presence of CO2 clathrates may provide a record of climate change that could only be
preserved in this unique setting.
JUSTIFICATION FOR SEDIMENT STUDIES
The sedimentary analysis of Lake Vostok is of particular interest
among Antarctic subglacial lakes by virtue of its size, thickness of
sediments, and because of the background information already
The ice core record collected at Vostok Station will be
valuable in conjunction with the historical sediment record for
reconstruction of the paleoenvironment of the lake.
particularly true for the accretion zone at the base of the ice
core. Furthermore, Lake Vostok’s size makes it the best candidate
for the existence of a stable microbial community and a long,
continuous sediment record.
SEDIMENT SAMPLING STRATEGY
Information that can be gained by in situ measurements at the
sediment/water interface will be limited.
Therefore, its strongly
encouraged that a strategy based on sample return be pursued.
Initial survey measurements can be accomplished remotely and by in
situ instruments, but in order to fully implement the science plan,
return of samples to the surface will be essential.
technological obstacle to the collection and return of 300 m of
sediment core will be creating and maintaining an access hole
through the deep ice. The Ocean Drilling Program (ODP) has already
developed many of the techniques necessary for collecting and
sampling cores of this length, and from this depth (in the ocean).
Some technology development would be required to utilize lake water
as drilling fluid to minimize lake contamination.
A suite of ODP
standard procedures currently used could be applied to Lake Vostok
sediments including: acquisition 300+ m of sediment core in
pressurized ten (10) meter sections for sampling; sampling of gas
hydrate formations; pore water sampling; down-hole logging;
establishment of long-term benthic monitoring observatories; casing
of the bore-hole for later re-entry if desired; and established
sampling and repository protocol.
It is recommended that methodology for investigating the lake
sediments proceed as
1. remote site survey (e.g. thickness of sediments, stratigraphy,
2. in situ sediment/water interface survey (use of resistivity
probes, video, sonar, particulate sampling)
sample “video grab” and return to the surface
establishment of long-term in situ sediment-water interface
5. collection of long cores
logging (e.g. geothermal heat flux, fluid flow)
7. cap hole for future re-entry if desired
Disturbance of the lake and contamination of the lake and samples
can be kept to a minimum through a number of initiatives:
1. sterilization of all equipment entering the lake to greatest
2. collection of the cores in sealed canisters so that there is no
loss of sediment on removal or contact of the sample with upper
strata as it is being raise through the water column; and 3. use of
benthic lake water as drilling fluid to reduce introduction of
NUMERICAL MODELING FOCUS GROUP CONCLUSIONS
Christina L Hulbe (archivist)
JUSTIFICATION FOR LAKE VOSTOK STUDIES
Lake Vostok is an unique physical environment which offers the
opportunity for new development of information, and a better
understanding of subglacial lakes.
The study of closed lake
circulation is new and therefore allows us to test and refine
existing models, and develop new models and theories. Furthermore,
available information suggests that Lake Vostok may be an analogue
for ice-covered planetary bodies.
NUMERICAL MODELING GOALS
Numerical modeling of ice sheet and lake behavior should begin early
in a Lake Vostok initiative and form a close collaboration with
other research communities before and after the direct exploration
of the lake.
Models will provide the best a priori characterization
of the lake environment, offer advice for drilling site selection,
and constrain the interpretation of observations made within the
Existing ice sheet/ice shelf models need little modification
to meet the requirements for such studies. However, the exploration
of Lake Vostok poses a new challenge for modelers of lake
circulation. The lake has no free boundaries, a unique physical
environment on Earth that may be an analogue for ice-covered oceans
on other planetary bodies.
The primary goal of an ice sheet flow/lake circulation modeling
effort is characterization of the lake environment. Simulations of
the modern ice sheet can provide three-dimensional views of
temperature in the ice and lake sediments, and of ice velocity.
Those results can then be used to predict the thermal environment of
the lake and the pathways and delivery rates of sediments through
the ice sheet into the lake.
Because basal melting is widespread
under the thick East Antarctic Ice Sheet, the lake probably receives
water and bedrock-derived sediments from the surrounding area. The
flow of water and sediments at the ice/bed interface, both to and
from the lake, should also be modeled. Another important use of the
results of ice sheet simulations will be in the prescription of
boundary conditions for lake circulation models.
will be influenced by gradients in ice temperature and overburden
pressure (due to gradients in ice thickness), and by meltwater flow
into and out of the lake along the ice/bed interface. The pattern of
ice melting and freezing predicted by a lake circulation model will
in turn be used to refine modeled ice flow over the lake.
circulation models will resolve the patterns of water temperature,
salinity, and clathrate (gas hydrate) distribution. Together, the
simulations will define the habitats in which lake biota exist and
can also be used to evaluate the constancy of those habitats over
Because the present state of the lake depends in part on past
events, it will be important to conduct full climate-cycle ice sheet
simulations. A coupled grounded ice/floating ice model that
incorporates basal water and sediment balance can estimate past
changes in lake water and sediment volume, including the possibility
of periodic sediment fill-and-flush cycles.
The proximity of the
Vostok ice core climate record makes Lake Vostok an ideal setting
for such experiments. Investigating the full range of time since the
lake first closed to the atmosphere is more challenging and may best
be accomplished by a series of sensitivity studies, in which lake
volume and melt water flow are predicted for extreme changes in ice
sheet geometry, sea level, and geothermal heat flux.
experiments can also be used to speculate about the likelihood of
modern hotspot activity, given what is known about lake extent and
volume. Perspectives on past lake environments may be used to
determine the best sites for lake sediment coring and will aid in
understanding present-day lake habitats and biota.
NUMERICAL MODELING JUSTIFICATION
Numerical modeling of Lake Vostok will be interactive with the other
areas of research undertaken at Lake Vostok, and will provide
valuable support information for these research objectives.
modeling will provide valuable information on lake circulation
characterization/ ice sheet flow, the role of past events such as
changes in lake water and sediment volume, and the possibility of
periodic sediment fill-and -flush cycles.
NUMERICAL MODELING STRATEGY
The first stage in meeting the modeling objectives for the
exploration of Lake Vostok should be model development.
whole ice-sheet systems must be constructed to properly characterize
ice flowing into the Vostok region. Nested models should be used to
provide the high resolution needed for detailed studies of flow in
the region. Existing models of grounded ice sheet and floating ice
shelf flow are sufficient for those tasks, provided grounding-line
flow transitions can be accommodated.
Basal water and sediment
balance models should be coupled to the ice flow model. Full
climate-cycle simulations should incorporate bedrock isostasy
accurately but in a computationally practical manner. New lake
circulation models must be developed to meet the challenge of Lake
Vostok’s unique physical setting, in which there is no free boundary
and clathrates (hydrates) are likely to be present in the water
New equations of state, that account for the lake’s
low-temperature, high-pressure, low-salinity setting, must be
developed. The optimal model will be three-dimensional, nonhydrostatic, resolving both vertical motions and convection, and
must be of fine enough resolution to capture details of what is
likely to be a complicated circulation pattern.
chemical models that use the products of ice sheet and lake
circulation models to simulate the lake’s biogeochemical cycles
should also be developed, although the final nature of such models
cannot be determined until lake waters are sampled (for example,
does the lake have a carbon cycle?).
The second stage of a Lake Vostok modeling effort should be the
integration of new data sets into the models. Regional topography,
especially lake bathymetry, will be essential for the fine
resolution needed to fully characterize the lake environment.
profiling of ice internal layers would promote studies of grounding
line dynamics. Simulations of the present-day system can make use of
existing ice sheet Digital Elevation Models and measurements of
surface climate. The Vostok ice core climate record is ideal for
driving longer-time simulations of ice sheet and lake behavior.
Improved knowledge of regional geology will be important, both rock
type - for model studies of lake sedimentation - and geothermal heat
flux - for ice thermodynamics.
Such regional data sets should be
developed before the drilling program begins, to give modelers ample
time to describe the lake environment, discuss preliminary results
with other project scientists, refine the models, and finally aid in
drill site selection. Lake circulation models, in particular the
development of an appropriate equation of state, will benefit from
the products of drilling and lake water sampling. Interaction
between modelers, biologists, limnologists, and the borehole site
selection group will be vital as models are developed and tested.
In a final stage, the fully-developed and tested models can be used
to link together observations made at discrete locations and to
develop a robust history of lake evolution. The unique physical
setting of the lake and its remoteness for observation demand an
interdisciplinary approach to this stage of the modeling effort,
including theoretical, numerical, and observational components.
NUMERICAL MODELING TIMEFRAME
Any time schedule proposed for a Lake Vostok initiative must
accommodate time in the predrilling phase for model development,
analysis, and interaction with other project scientists. That
development can proceed in tandem with preliminary geophysical
surveys of the Vostok region.
Model simulations should be analyzed, in conjunction with
geophysical surveys, prior to drilling site selection in order to
identify areas of special interest (for example, likely sites of
thick sediment deposits). Once sampling has begun, lake circulation
models can be tested and improved and biogeochemical models can be
Finally, modelers can work with biologists, geochemists,
and limnologists to develop a comprehensive understanding of the
lake’s unique physical and ecological systems.
SITE SURVEY GROUP CONCLUSIONS
Brent Turrin (archivist)
JUSTIFICATION FOR LAKE VOSTOK STUDIES
Lake Vostok provides a rare opportunity for an interdisciplinary
study of an extremely cold, dark, high pressure aqueous environment.
The chance to study the synergy between geologic/ geochemical
processes and biologic/biochemical processes that define this
distinct aqueous system may lead to new fundamental understandings.
SITE SURVEY GOALS
The primary goal of a site characterization study at Lake Vostok is
to acquire the critical regional information both across Lake Vostok
and the surrounding area to constrain the flux of material across
and into the Lake, and to provide insights into the geologic
framework for the Lake.
These improved datasets will provide
critical insights into selecting sites for installing observatories
and acquiring samples.
Site selection would best be facilitated by
generation of a high-resolution 3-D geophysical image of the
ice-sheet, water body, the lake sediment package, and bedrock. This
3-D image would address ice-sheet thickness and structure as well as
dynamics; water-depth and aerial extent; lake sediment thickness and
distribution; and bedrock topography, structure, and lake
These data sets will also provide input for ice sheet
and water circulation models.
SITE SURVEY JUSTIFICATION
Lake Vostok is the largest subglacial lake yet discovered.
of its size, Lake Vostok will have a greater influence on ice
dynamics than a smaller subglacial lake. Therefore, it provides a
superior natural laboratory for studying the phenomena of ice
dynamics such as grounding/ungrounding and the associated
stress/strain regime and mass balance considerations, in both the
transition and upstream-downstream environs.
In addition to providing an occasion to study ice dynamics, the
drilling of Lake Vostok will also provide an opportunity to sample a
distinct extreme (cold, dark, high pressure) aqueous environment.
Biologic and biochemical sampling of Lake Vostok could lead to the
discovery of new organisms and enzymes with potentially invaluable
Geologic, geochemical and geophysical studies will lead to a better
geology of Antarctica
(2) how geologic/geochemical processes
interact with biologic and
biochemical processes that define this distinct aqueous system
SITE SURVEY STRATEGY
The site survey strategy is broken down into two components:
airborne studies; and ground-based studies.
The airborne studies consist of collecting aerogravity data, aeromagnetic data and
coherent radar data. These data sets would be enhanced by
ground-based seismic studies, and by
the installation of a passive seismic and Global Positioning
Satellite (GPS) network around Lake
The seismic studies should be further broken down into two
phases. First, a preliminary pilot study, where data collection is
concentrated mostly in the Lake Vostok area proper, and second, a
high-resolution seismic study in which the seismic lines are tied
into the existing regional seismic data.
SITE SURVEY TIME FRAME
The group feels that the necessary data can be collected and
evaluated in two years/field seasons.
In year one four separate
teams would be needed. Team one, would be responsible for the
airborne geophysical studies; gravity, magnetics, and radar. Team
two, would conduct the pilot seismic study. The third team would
install the passive seismic and GPS nets. The fourth team will
conduct radar 3-D imaging studies on and around Lake Vostok.
Year two, would be devoted mostly to a collaborative international
project collecting high-resolution seismic data, tied to existing
TECHNOLOGY DEVELOPMENT WORKING GROUP CONCLUSIONS
Frank Carsey (archivist)
JUSTIFICATION FOR LAKE VOSTOK STUDIES
Why should we study Lake Vostok?
The lake is unique and interesting
because of its immense size, isolation, high pressure, low
temperature, estimated age, water thermodynamics, contamination
concerns, habitat, biota, sediments, geological setting and possible
The broad goal of Lake Vostok exploration is to access the lake
water and sediments in a noncontaminating fashion, obtain certain
physical, chemical and biological measurements, as well as retrieve
water and sediment samples for study in the laboratory.
aspects of this program have never been done and have no documented
The areas which require technologic development are
1. Site Selection. The lake is large. Presently the satellite
altimeter and limited airborne radar data point to the presence of
numerous, varied interesting sites but rigorous site selection
requires improved regional data. Well-planned airborne geophysics
and seismic programs are necessary to complete the specification of
the lake, its ice cover, and its sediments. In this regard, ice
penetrating radar is a key means of observing the ice, providing
estimates of ice ablation and accretion over and near the lake. The
technology of sounding radar has developed rapidly in recent years.
To generate accurate data on ablation and accretion as it varies in
the lake environs, optimized radar configurations should be employed
in the site survey.
2. Entry Means. The emerging scientific goal
requires robotic, observatory installation and sample-return
programs. These approaches necessitate different means of obtaining
access to the lake water, ice surface, lakefloor, and sediment. None
of these approaches has ever been demonstrated through 3700 m of ice
or within a lake of this pressure-depth.
Prevention. Access to the lake, activities within the lake,
withdrawal from the lake, any equipment abandoned in the lake, and
possible unplanned experimental difficulties in the course of
studying the lake must be proven to be safe with respect to
contamination by living microbes.
4. Sampling Requirements. Preliminary scientific goals point to
physical, chemical, and biological observations of the ice above the
lake, the lake water, the lakefloor, and the sediments, at several
sites. To understand the three dimensional system within the Lake
several in situ robotic, observatory installations and sample-return
efforts will be necessary. On the whole, these campaigns require
accessing the lake in at least two different ways, one way for
robotic vehicles and observatory installations and another for
Contamination issues are significant for both
approaches. In addition, some means of sampling within the lake is
required, e.g. something simple such as a vertical profile to the
lake floor from the entry point, or something more complex such as
an autonomous submersible vehicle.
The sediments must be sampled; it
is probable that in situ sampling of the pore water and structure of
the upper sediment layers will precede sample return of sediment
The lake floor itself should be observed, both the sediment
and basement rock areas, for paleoenvironmental and sedimentation
studies. Finally, the water, ice, and sediment must be observed and
analyzed in situ for composition, microbial populations,
stratification, particulate burden and nature, circulation, and
In situ Observations and Robotics. In the past few years the
capability for robotic activity and in situ measurements with
micro-instrumentation has grown immensely; in coastal oceanography
it has significantly changed spatial data gathering, and the Ocean
Drilling Program is now interested in this kind of data acquisition
Also, NASA has undertaken a significant program of in situ
development for solar system exploration.
The goals of Lake Vostok
exploration have much in common with those of oceanographic and
planetary work, and this overlap of interests provides an avenue for
economy and creative collaboration which the Lake Vostok exploration
Technology development is a resource investment, and an appropriate
question in a discussion of it concerns its inherent value, i.e.,
the importance of its immediate use and its applicability to other
To address the first issue, the question “Why Lake Vostok?” is
Lake Vostok is scientifically unique and interesting because
it is large and deep, essentially isolated, at high pressure and low
temperature, old, fresh (as nearly as can be determined), the site
of interesting water thermodynamics and dynamics, underlain by deep
sediments of biological and geological promise, in an interesting
geological setting, characterized by several unusual sorts of
habitats, strongly influenced by the overlying ice sheet, and
analogous to interesting planetary sites.
Taken together, the
pressure and temperature regimes and the ice sheet processes give
rise to another interesting aspect; they indicate that the gases
present will be in clathrate (gas hydrate) form, and this provides a
key biological question regarding the ability of microbes to utilize
The second category addresses whether the technologies of Lake
Vostok exploration are of use in other pursuits. Clearly they are.
The tools and techniques needed for Lake Vostok site survey and in
situ campaigns are applicable to ice sheet and permafrost studies,
in situ water and sediment composition analysis, device
miniaturization, sterilization and sterile methods development,
biological assessments, seafloor characterization, radar surveys in
other sites and even other planets, and similar problems.
The pathway of activity to lead from this workshop to the actual
initiation of Lake Vostok campaigns is complex, with some elements
that can, in principle, be conducted in parallel.
Technology development precedes field deployments; thus, with the
exception of procedural and
legal issues related to contamination control, the technology will
come first and determine the
earliest date that performance data or testing results can be
available. Clearly, the technology time frame is of crucial
importance; what controls it?
The following approximate high-level
sequence of activities is suggested.
1. Interagency International Interest Group. The science and
technology of Lake Vostok, and similar sites, is relevant to several
agencies and a number of national Antarctic programs, and possibly
industrial supporting partners. A group representing interested
agencies should be formed to outline possible lines of support.
2. Science Working Team. Before any implementation can begin, a
working team of scientists, engineers, and logistics experts must be
appointed to establish science requirements for the first campaign,
and a general sequence for future campaigns.
3. Site Survey and Selection Team. A working group on site selection
issues and information needs, should meet immediately to set forth
what data should be sought.
4. Observation and Sampling Strategy. A
strategy of measurement and sampling needs can be constructed as
project scenarios, flexible enough to adapt to varying success rates
for the development activities.
5. Technology Plan. A plan is needed for technology development and
testing, including subsystem level functional units as well as
integrated systems and including contamination prevention procedures
and validation at each step. This will include documentation of
requirements, priorities, constraints, information system roles, and
phasing of deployment and integration. The plan should be viewed as
a roadmap and a living document, and its architecture is not
specified here as there may be effective web-based methods for its
6. Technology Implementation. Development of
implementation teams to obtain funding and perform the functional
unit development. Selection and recruitment of these specialists
groups are key tasks. Actual development of technologies will
follow, and coordination of developments is needed.
7. Testing. The subsystems, the integrated systems, and the
contamination prevention techniques all require realistic testing.
These testing regiments are demanding and can be expensive, but they
are not as expensive as failure during a campaign. The testing of a
given subsystem, e.g. an instrument to obtain chemical data from the
lake water, may well call for deployment in an analogous
environment, e.g. an ice-covered lake, and this deployment could be
costly unless it is collaborative with other investigations of
ice-covered lakes. To optimize the testing process, planning,
coordination and collaboration are essential.
1. Summary of Actions. From above, the actions required for a Lake
Vostok program include interagency communications, science and
engineering team definition work, development of technology
requirements and project scenarios, system definition, subsystem
development (including integration and test), system level test, the
first Lake Vostok entry, and the subsequent review of status to
determine future directions.
2. Crucial Technologies. While much of the technical work required
for a successful Lake Vostok exploration is challenging, most of the
technologies are seen to be within reach, and many of the tasks have
several candidate approaches. An exception is contamination control;
this technology is challenging in both development and validation,
and it should be developed and proved before any in situ examination
of the lake can be addressed. Apparently, this work has begun within
NASA, and at the earliest opportunity an estimate of the time
required for its completion should be requested.
3. Other Timetable Considerations. In assessing the technology
timeframe it is necessary to
understand the overall schedule constraints, e.g. contamination
prevention, development of consensus on scientific objectives and
requirements, logistical resources and commitments, site surveys,
international participation, etc. From an initial assessment, it
appears that site surveys may be addressable as early as in the
00-01 field year (but maybe later), and this seems to be the
schedule driver. From the perspective of participating scientists,
the field work could begin in the field season of the year following
the site survey, assuming that site survey data can be made widely
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