Geoscience Reference
In-Depth Information
being pushed forward at greater rates. This could increase the volume of rock and the
distance of which rocks are being delivered down valley. Regulations should limit
hiking in these high-use wilderness areas, or in densely populated regions, policies
need to be implemented to restrict development. If drainage is limited as rocks fill
pore spaces, water could also accumulate at the surface of the concave toe of the
rock glacier. The rock glacier could act as a dam, filling until a breach occurred,
flooding nearby communities in populous alpine areas.
If the climate warms and ice is melted, the additional solutes contained in this
water source could affect water quality in nearby alpine lakes and streams (Thies
et al.
2007
). Most urban areas near mountains rely heavily on snowfall and glaciers
for a large quantity of water. Increased nitrate deposition because of synthetic
agricultural fertilizers or driving cars that release nitrous oxides has been linked
to increased eutrophication, or excess algae growth, in alpine areas. Not only is
eutrophication of concern because of algae's bad taste or odor, but it is also a prob-
lem because increased total organic carbon requires more disinfection which adds
more chemicals to the water. Improved regulations may be needed to limit human
nitrogen emissions if naturally occurring chemical weathering of rock can also add
significant amounts of nitrates to pristine alpine waters.
More importantly, the techniques used to monitor California rock glacier can also
be utilized in areas where similar phenomena can have a greater human impact. For
instance, similar methods can be used to map, monitor, and assess hazards for roads
or major highways that transverse mountain ranges or for alpine cities or towns
that rest in valleys that are susceptible to high magnitude, low frequency, geomor-
phic processes. Debris flows, mudflows, rockfalls, slumps, landslides, avalanches,
or other processes that are sensitive to melting ice or permafrost could be monitored
using similar techniques to manage sensitive alpine areas.
Ideally, hazard assessment should employ multiple sources of remotely sensed
and GIS data, but analysis is often dependent upon what data are available, data
quality, and spatial, spectral, and temporal resolution (Giardino et al.
2004
). Detailed
studies that rely on motion detection should use a combination of aerial pho-
tographs, field, Synthetic Aperture Radar (SAR), and Light Detection and Ranging
(LiDAR) data sources. At a more regional scale, Advanced Spaceborne Thermal
Emission and Reflection Radiometer (ASTER), Satellite Pour l'Observation de la
Terre (SPOT), and Landsat Enhanced Thematic Mapper Plus (ETM+) could be used
to measure and map the changing extent of glaciers, growing supraglacial lakes, the
timing of snowmelt, or historical landslides or avalanche paths (Huggel et al.
2002
;
Quincey et al.
2005
; Roessner et al.
2005
; Paul et al.
2007
; Kääb
2008
). The tradeoff
between detailed observations and regional assessment is most easily evaluated on
a case-by case basis of hazard type; however, image fusion techniques show much
promise to assess hazards at the local and regional scale (Kääb et al.
2005
).
5.5.5 Andean Glaciers Application
Current levels and future projections of greenhouse gas emissions in the atmosphere
indicate that the planet is experiencing accelerated environmental change (IPCC
