New & Noteworthy
 Ground-Water Availability in the United States (Circular 1323)
CFP: Conduit Flow Process for MODFLOW-2005
GSFLOW: A New Model for Simulation of Ground-Water and Surface-Water Interaction
SEAWAT v4: Simulation of 3D Variable-Density Ground-Water Flow and Transport
USGS in Your State
USGS Water Science Centers are located in each state.
![[Map: There is a USGS Water Science Center office in each State.]](https://webarchive.library.unt.edu/eot2008/20080922162432im_/http://www.usgs.gov/frameworkfiles/includes/imagemaps/usmapsmall.gif)
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Karst -- Photos of Carbonate Aquifers
Click on photos for full size.
Photo by Dan Hippe
Field crews access karst springs
along the Flint River, southwest, Georgia, in
order to inventory inflow and evaluate spring
water quality and flow characteristics.
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Photo by Dan Hippe
Gary Holloway welds glass ampules
for CFC age dating of spring discharge from the
Upper Floridan aquifer to a spring pond located
in the Dougherty Plain of southwest Georgia.
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Photo by Gary Holloway
Dan Hippe makes discharge measurement
of Upper Floridan aquifer spring that flows into
the Flint River near Albany, Georgia.
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Photo by Andy Hickey
During hot summers, deep holes of
cool water at karst springs are critical habitat
for striped bass in the Flint River and Lake Seminole
in southwest Georgia. Sustained droughts and extensive
pumping of the Upper Floridan aquifer could decrease
spring flows and adversely effect these habitats.
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Over 700 sinkholes formed in response
to developing a well with air in the highly karstified
Upper Floridan aquifer at the Pasco/Citrus County
line in west-central Florida, February 1998. The
well had been drilled about 20 feet into a cavity
(no circulation), then air lift methods were used
to develop the well. Immediately after air-lift
methods began, small sinkholes started appearing
all over the 20 acre area. The well development
was abandoned and the crew tried to move equipment
and themselves off site as trees toppled around
them. Subsidence continued for several hours and
the initial sinkholes, closest to the well, expanded
to become the largest in the area.
Photo by Ann Tihansky
February 1998, subsidence event
in highly karstified Upper Floridan aquifer at
the Pasco/Citrus County line in west-central Florida.
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Chief Hydrologist, Bob Hirsch,
experiences karst terraine first hand while kayaking
on Cedar Creek. He is paddling out of a cave.
Cedar Creek, about 20 miles south of Winchester,
is a tributary of the North Fork of the Shenandoah
River. The confluence is at Strasburg, VA. In
2005 there are two streamgages on Cedar Creek
- one is realtime the other is not.
![[Phot: Bob Hirsch (USGS) paddling out of cave.]](photos/Hirsch_CedarCrksmall_thumb.jpg)
Photo by Mary Cirincione
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Photo by Eve Kuniansky
Inside the Edwards-Trinity Plateau aquifer, Sonora
Caverns, Sonora, Texas.
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Photo by Eve Kuniansky
Looking up at the vertical joint at the top of
the cavern inside the Edwards-Trinity Plateau
aquifer, Sonora Caverns, Sonora, Texas. These
types of large chambers beneath vertical joints
are common in Texas caves.
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Photo provided by Chuck Taylor and Earl Greene
Aerial view of a large sinkhole on a farm near
Mitchell Indiana.
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Photo provided by Chuck Taylor and Earl Greene
An artesian "blue-hole" spring, 60 feet in diameter,
Orangeville Rise in southern Indiana.
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Photo provided by Chuck Taylor and Earl Greene
Solution-enhanced valley formed by erosion and
collapse of bedrock over a near-surface conduit,
Mitchell, Indiana.
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Photo provided by Chuck Taylor and Earl Greene
A small collapse sinkhole with an open throat
is called a swallet. This one is about 3 feet
in diameter. These types of sinkholes are ideal
dye-injection sites for testing if this area is
hydraulically connected to a nearby spring.
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Photo provided by Chuck Taylor and Earl Greene
Regolith collapse in central Kentucky.
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Photo provided by Chuck Taylor and Earl Greene
Streamflow is gradually lost through a series
of alluvial swallow holes. This view is taken
from the terminal swallow hole.
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Photo provided by Chuck Taylor and Earl Greene
Chuck Taylor stands next to a stream that enters
the subsurface through a cave entrance (somewhere
in Kentucky).
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Photo provided by Chuck Taylor and Earl Greene
Putting rhodamine WT into a sinking stream in
Hardin County, Kentucky.
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Photo provided by Chuck Taylor and Earl Greene
Chuck Taylor poors fluorescein dye in a large
(50 foot) diameter sinkhole near Danville, Kentucky.
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Photo provided by Chuck Taylor and Earl Greene
Visual dye detection--Fluorescein dye resurges
at a visible concentration from the spring. This
is confirmation that this spring is hydraulically
connected to the area where the dye was injected.
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Return to USGS Ground Water -- Karst home page
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U.S. Department of the Interior |
U.S. Geological Survey
![[Phot: Bob Hirsch (USGS) paddling out of cave.]](photos/Hirsch_CedarCrksmall.jpg)
