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On
a planetary scale, there is a lack of information about the
spatial distribution and areal extent of surface materials and
climatically-generated landforms. For example, we have no idea how much
land
area currently generates dust due to wind erosion of degraded
soil, but even more importantly how much more land is susceptible
to dust-generation with a small change in climate. And dust is just one
of the components of the system, and dust generation just one of the
processes. Paleoclimatic surfaces like desert pavements have been
stable and exposed to the atmosphere for over a million years. What is
the susceptibility
of these surfaces to changes in the hydrologic cycle. Or,
alternatively, do these surfaces evolve to buffer the landscape as
climate changes? But this is getting into the details and drivers. At
the moment, we simply need to quantify the distribution of materials
(soil, sediments, rock, dust) alongside vegetation cover. At that point
we can start to apply the models of surface processes on a large scale.
My research is the further development of what I started with TES and
THEMIS data,
but now applied to Earth data and processes. It was the combination of
a number of complex models (atmospheric radiative transfer, solar
thermal cycling, compositional deconvolution) that allowed us to
map the distrubution of sediments on Mars from space. I took the
spatial distribution of rocks, sand, and dust to interpret what are the
most recent processes at work, and how they have changed older
surfaces. Using diurnal
temperatures
to determine the mechanical
composition of surface materials and relate these properties to
environmental conditions, we are able to build a global 3-D view of the
surface, and interpret the history. Earth and Mars are similar enough
that the lessons we learned from one can guide the plan for
investigating the other.
Starting on a regional scale,
I am working on generating a map of the planet (Earth) showing the
materials
and
processes, using the same methods we used on Mars. The
applications of such a dataset are numerous. A map of surfaces
and processes can be used as an input into climate models, determining
the scale and potential for feedback mechanisms. Second, in combination
with climate models, we can generate a map of regions and surfaces that
are likely to cause problems such as what occurred during the 1930's
dust
bowl, or wide-spread erosion due to drought.
The
processes and surface characteristics are currenly fairly
well-understood, and the climate models are pretty advanced. The big
thing that is lacking is the spatial quantification and map of these
things. MODIS and ASTER have been collecting data for a number of years
now and provide a complete global view of the planet
at all the right wavelengths. One problem is that only geological
remote sensing magicians can get the information out. Thus, there needs
to be a concerted effort to turn the mutispectral data into a GIS-based
series of products that modelers, engineers, and economists can
actually use. Thanks to the efforts we put into TES and THEMIS, there
is a model for
how to do this. I am in the process of developing prosals to do just
that: 1) refine and apply the thermophysical models to determine
surface mechanical composition on Earth; 2) turn these models and
observations into geologically interpretable information that is useful
for others to use; 3) calibrate, rectify, and mosaic the global ASTER
dataset into a useful product; and 4) generate the maps of surface
properties and processes that can be directly interpreted and used in
GIS' for climate modeling, land management, and disaster mitigation.
Science
Plan:
Development
of a comprehensive model of physical properties of natural
surfaces as a function of mode of emplacement, envionment,
and age.
Practical
Objectives:
1)
To characterize a series of primary (volcanic, depositional) surfaces
based on remotely
sensed measurements, and quantitatively link these measurements to
physical properties and environmental conditions.
2)
To characterize of a series of modified (fluvial, mass-wasting, and
glacial)
surfaces
based on remotely-sensed
measurements, and quantitatively link these measurements to physical
properties and environmental conditions.
3)
Development of an empirical model of surface property (thermal
conductivity, clast size-frequency distribution, reflectivity,
composition, scale-dependent roughness, slope) and bulk property
evolution (density, morphometry, clast distribution) as a function of
process and time to determine zones of convergence of properties from
remote sensing.
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