PLRP DEEPWORKER DEPLOYMENT 2008 -- SCIENCE PLAN

**[PROJECT EXECUTIVE SUMMARY:]{.underline}** The deployment of
DeepWorker submersibles into Pavilion Lake, Canada (50°51\'57\"N,
121°44\'20\"W), presents a unique opportunity to advance the long-term
objective of human exploration of the Moon and Mars. By combining
rigorous scientific research on life in extreme environments with high
fidelity training in an underwater, remote field setting, this will
serve to inform the knowledge base, tools and techniques of future human
missions to the Moon, Mars and beyond.

![](media/image1.jpeg){width="1.5in" height="1.875in"}

[2008 FIELD DATES]{.underline}

June 21-July 11, 2008

(DeepWorker deployment from June 23-July 3)

[NASA Field Participants]{.underline}

Darlene Lim - NASA ARC/SETI

Chris McKay - NASA ARC

Michael Gernhardt - NASA JSC

Alfonso Davila - NASA ARC/SETI

Patricia Montgomery - NASA ARC

**[DEEPWORKER SCIENCE PLANS:]{.underline}**

> **[Justification for use of DeepWorkers to meet PLRP science
> goals:]{.underline}**

-   SONAR suggests lake bottom is covered in microbialites, however,
    ground-truthing of sonar imaging data from Pavilion Lake has not
    been accomplished, as such, the extent and variability of deepwater
    microbialites is not yet known.

-   Further, the inability to directly access deepwater microbialites
    means that very limited information has been obtained on their
    morphology, relationship to environmental factors (e.g. temperature,
    light, water geochemistry) and chemical/isotopic characteristics.
    Understanding these variations is fundamental to understanding the
    mechanisms and timing of microbialite formation.

-   The deep regions of Pavilion Lake are too large and deep to explore
    and sample efficiently and safely using conventional SCUBA, and
    remote (SONAR) data provide limited interpretation.

-   [Solution:]{.underline}

DeepWorker submersibles will help PLRP members reach our science goals
by using an exploration mechanism consistent with the following
requirements for exploring pristine, vulnerable, astrobiologically
relevant environments:

1.  Safety

2.  Environmental Stewardship

3.  Relevant Science

4.  Advancing Human Exploration

> **[PLRP Science Objectives:]{.underline}**
>
> The PLRP is a NASA-UBC led multi-disciplinary initiative (see
> <http://supercritical.civil.ubc.ca/~pavilion/> for more information).
> Project members have been conducting science and exploration
> activities in the Pavilion Lake region since 2004. The primary funding
> for this project comes from the Canadian Space Agency, with additional
> financial contributions from NASA, the National Geographic Society,
> McMaster University and Nuytco Research. 
>
> ![](media/image2.jpeg){width="2.25in" height="1.4680555555555554in"}
>
> The overarching goal of the PLRP is to understand the mechanisms of
> formation of the unique microbialites in Pavilion Lake and the
> potential for associated biosignatures. This understanding will
> contribute to astrobiology research by providing the basis for
> interpretation of similar organo-sedimentary structures either on
> early earth (e.g. stromatolites) or potentially on other planets.
>
> The following is a list of the on-going PLRP science objectives:

1.  General Limnology of Pavilion Lake and surrounding water bodies

    -   Chemical and Physical characteristics

    -   Stable Isotopic (C, O, H) characterization; carbon-sources;
        groundwater-provenance

    -   Water budget and balance

2.  Microbial influence on carbonate formation

-   Isotopic tracers of inorganic and organic carbon sources

-   Microscopy and molecular characterization

3.  Microbialite mapping

-   Lateral and Vertical variability

-   Correlation with environmental factors (e.g. groundwater inputs,
    light)

4.  Contextual comparison to other microbialite/carbonate rich lakes.

5.  Determine the spectral (visible to thermal infrared) and erosional
    properties of the carbonates.

6.  

DeepWorker deployment in Pavilion Lake will directly support PLRP
Science Objectives 2 and 3.

[Summer 2008 Field Activities - DeepWorker Submersibles: Analog Science
Missions]{.underline}\
Dates: June 21-July 11, 2008. We will be

[NASA Field Participants]{.underline}

Dr. Darlene Lim - NASA ARC/SETI (PLRP PI)\
Dr. Chris McKay - NASA ARC (PLRP Science Advisor)\
Dr. Michael Gernhardt - NASA JSC\
Dr. Alfonso Davila - NASA ARC/SETI\
Patricia Montgomery - NASA ARC (PLRP E/PO Lead)

**[DeepWorker 2008 Science Plans:]{.underline}**

## Contribution to Microbialite Mapping - Science Objective 3

To address our mapping goals, we will carry out the following science
plan during the 10-day excursion to Pavilion Lake from June 23-July4,
2008:

1\. Contour Mapping:

> To understand the spatial coverage and variability of microbialites in
> Pavilion Lake, DeepWorker transects at set contour depths will be
> carried out. Still and digital photographic data, and GPS data will be
> compiled. Transect coverage will be by 10m intervals (i.e. 5 m, 15 m,
> etc... Note: these are nominal depths -- actual operating depths are
> to be determined based on SONAR data), and grouped as follows for the
> purposes of designating teams to each task:

-   Shallow contours -- 5 and 15 m

-   Intermediate contours -- 25 and 35 m

-   Deep contours -- 45 and 55 m

![](media/image3.jpeg){width="6.246527777777778in"
height="4.6722222222222225in"}

*Figure 1. Pavilion Lake with contours at 5, 10, 15, 25, 35, 45, and 55
m.*

2\. Basin Mapping:

-   The deepest regions of Central (40-60m), North (30-40m), South basin
    (30-40m) will be photographed, and mapped for unusual and
    interesting features

3\. 'Bioherm' Mapping:

> Bioherms have been identified in several portions of the lake. This
> includes the large bioherms visible from the surface in the Central
> basin, and smaller bioherms identified through SONAR and drop camera
> data at 35 - 55 m depths in the Central and North Basins of Pavilion
> Lake. Other potential bioherms have been identified through SONAR data
> throughout the lake.
>
> Using DeepWorkers, we will:

-   Visually document, and map the known bioherms through top-to-bottom
    contours,

-   Ground truth SONAR data of potential bioherms,

-   Similarly map any newly discovered bioherms,

-   Ensure that groundwater inputs, faults, etc are documented and
    mapped

4\. Groundwater Inputs:

Any identified groundwater inputs will be carefully visually documented
and GPS coordinates will be recorded for these important features.

-   Detection of groundwater inputs via temperature and chemical
    differences identified via a CTD installed on the DeepWorker and
    operated during mapping exercises

-   Combine investigation of these identified sites with the UBC GAVIA
    AUV to further interpret GAVIA results

-   Provide indicators of groundwater inputs that may be further
    investigated using GAVIA

5\. Photography of any visible salinity and thermal boundaries

6\. Mapping of rock debris flows throughout lake

7\. Vertical transects along identified regions of interest:

-   Vertical transitions are likely going to be important in attempting
    to link macro-scale morphology with environment.  

## Contribution to Microbial Influences on Carbonate Formation -- Science Objective 2

Distinguishing between mechanisms (abiotic versus biotic) of
microbialite formation is crucial to the interpretation of biosignatures
that may be preserved in similar structures on the early earth or other
planets such as Mars.

Results of natural abundance isotope analysis (^13^C, ^14^C) of
currently accessible (\< 35 m deep) microbialites indicate the potential
for input of carbon from regional groundwater to Pavilion Lake dissolved
inorganic carbon (DIC) as well as to the microbialites themselves. The
results obtained for the single, small deepwater sample obtained (\> 35
m) indicates that the proportion of old carbon is greater for this
sample. This suggests variability in the carbon inputs to the deep
portions of the lake or differences in the time of microbialite
formation within the lake.

DeepWorkers will enable:

1\. Direct sampling of deep microbialites (40 + m), which will allow for
the:

A.  Characterization of microbial community structure and isotopic
    indicators of metabolic activity at these depths

B.  Identification of isotopic constraints on carbon sources for the
    microbial communities and microbialite carbonate

C.  Correlation of isotopic samples to mapping of geochemical and light
    conditions

D.  Ultimately, constraint of the growth mechanisms and rates of
    microbialite structures

2\. The photo and video documentation, and mapping of sites of interest
for future detailed sampling. Data gathered about microbialite
morphology variability and distribution will be most useful to the
science community if it can be clearly linked with internal morphology,
and local and lake-wide geochemistry.

**Images from May 2008 PLRP DeepWorker Training Session in Vancouver**

![](media/image4.jpeg){width="5.125in" height="7.6875in"}

NASA Astronaut Dr. Michael Gernhardt preparing for launch in

DeepWorker submersible (May 2008; photo credit: L.Stang)

![](media/image5.jpeg){width="5.591666666666667in" height="8.3875in"}

Dr. Darlene Lim preparing for launch in DeepWorker submersible (May
2008; photo credit: L.Stang)

![](media/image6.jpeg){width="5.691666666666666in" height="8.5375in"}

(May 2008; photo credit: L.Stang)