Some of the students and Dr. White on the Salt Creek boardwalk
Paula presents her poster on
groundwater hydrology and ecosystems with some help from Dr. Wilson
by Paula R.
Salt Creek is one of the few
bodies of water in Death Valley which flows above ground for some distance
throughout the year. Located in the northern portion of Death Valley,
Salt Creek is, as its name implies, salty. Its salt content ranges from 35
parts per thousand to about four times that when evaporation is at its
highest point. Salt Creek runs several kilometers in length with
approximately three to four kilometers running above ground surface in the
winter and one kilometer or less running above ground surface in summer.
Groundwater in Death Valley is provided by snowmelt from the Panamint,
Funeral and Black Mountain Ranges as well as heavy rainstorms which
occasionally flood the valley’s canyons and inundate streambeds. Local
tectonics also contribute significantly to groundwater flow.
The three types of faults in
Death Valley have different consequences for flow. Compressional and
shear faults are likely to deflect groundwater while tensional faults
become preferential conduits for flow as blocks are pulled apart and space
is created between them. The Salt Creek marsh is controlled by a fault
where the rising block’s low permeability forces groundwater up above
ground surface from the falling block (Fig 1).
Within Salt Creek, there is
a population of pupfish known as Salt Creek Pupfish, Cyprinodon salinus
salinus. These fish are approximately six centimeters in length and
traverse the length of Salt Creek as it diminishes in summer and expands
in winter. Their lifespan is usually less than one year. These pupfish
are extremely adaptable, surviving temperature fluctuations from as low as
freezing to above 40°C, and salinities up to nearly 80 ppt. E. L.
Rothfuss, Superintendent of Death Valley National Park, has recommended
that the Salt Creek Pupfish be listed as threatened though it is not in
danger of extinction by human interference; their small population is
attributable to the size of their natural habitat and to the fact that a
female spawns only one young at a time, though she may spawn several times
each season. Flash flooding can wash young from the main stream and
isolate reproductively mature individuals from the gene pool.
Faunt, Claudia C. Effect of faulting on
ground-water movement in the Death Valley Region, Nevada and California.
USGS Water-Resources Investigations Report 95-4132. Denver, Colorado: USGS
Kirk, Ruth. Exploring Death Valley. 3d ed.,
Stanford, California: Stanford University Press, 1977.
Creek Pupfish.” California Department of Fish and Game - Habitat
Conservation Planning Branch. Accessed on 9 April 2004: http://www.dfg.ca.gov/hcpb/.