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An internet-based
electronic publication of Hazlett-Kincaid. Copyright © 2000.
Hazlett-Kincaid, Inc. All rights reserved.
Volume 1, Number 7 (November 2000)
Good Science
A Definition of Karst
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Good Science - An Editorial Comment
 You
may frequently hear the phrase "good science" tossed
around. To different people, this phrase may have vastly different
meanings. Recently, during a trip to Orlando Florida for a meeting
of the Hydrogeology
Consortium, it became apparent what "good science"
meant to me and what I think it should mean to others as well.
The legislative branch of government makes laws.
That is what they do, it is their focus. Agencies like the DEP
enforce the laws, in particular, environmental laws, laws associated
with waste disposal, laws associated with water use and abuse, etc.
Planners decide what land should be used and when and how.
Permitters issue permits to allow for a specified (planned) use. In
every state, and especially a water-rich state like Florida, every
one of the decision makers at these agencies ultimately relies on
the expertise of a scientist or engineer for guidance. One of the
recurring themes at the conference in Orlando was that sound
technical guidance is required for most decisions being made, yet
few people know where to turn. Often, technical assistance is sought
out at other agencies, in a circular fashion, each agency hoping
that the other can handle the situation.
This is where "good science" comes in.
As scientists, I think that we are obliged to offer an opinion when
an opinion is sought. Too often, we hear what people really think
behind closed doors or after the fact. Much of the inability to take
a stand comes from the fear of litigation. Just remember, lawsuits
don't have a leg to stand on unless there are damages. Many of you
have lots of education and/or experience....use it to render an
opinion.
"Good science" not only means that you
should offer your opinion, but that your opinion should be well
informed, thoughtful, and predicated on objectivity. Too many
scientists are hired guns, brought in to construct the answer
that is sought, rather than letting the cards fall where they may,
based on sound scientific principles.
The time is now for "good science" and you
are the good scientists. Government agencies, private
industry, and private citizens will all benefit from a freshly frank
approach to decision-making, where the experts actually offer their
opinion!§
A Definition of Karst 
Aerial
photograph of a classic karst terrain north of Lewisburg, WV. Taken
from a small plane by William K. Jones
If you read the above article, you will recall that
I recently returned from Orlando, where I attended and spoke at a
meeting of the Hydrogeology
Consortium. The consortium was more or less established to
heighten awareness of groundwater issues in Florida, particularly as
they pertained to the special geology underlying most of the state.
The special geology seen in Florida today got it's
start some 20 to 58 million years ago when Florida was an active
carbonate platform. Over that time period, carbonate rocks piled up
to a thickness of 5000 meters, in places. This sequence of rocks is
the upper and lower Floridan aquifers and their many sub-units. Near
the end of this time period, the Hawthorne Formation, consisting of
phosphatic clay interbedded with limestone, was deposited and has
been eroding northward ever since. Sea level changes elevated much of the Florida
platform exposing the carbonate rocks to dissolution by
meteoric precipitation. The result has been the
widespread formation of caves and sinkholes in what is typically
described as a karst aquifer.
Karst
features greatly complicate the accurate prediction of
groundwater flow patterns due to the extreme anisotropy they create
in the aquifer and the difficulty of detecting karst features with
standard point-sampling techniques. A more
fundamental problem however, is the ambiguity of the definition of a
karstic environment which is variably used to describe
landscapes, rock, geochemical processes, and/or permeability
structures. Before, we can move forward with solutions for
water resource problems in karst aquifers, we must focus on the
aspects of karst that are most significant to groundwater flow
directions and rates.
Toward
that goal, let us briefly explore a few definitions.
(The
following is from Groundwater Models for Resources Analysis and
Management, a 1995 publication by CRC Press - Chapter 19 "Is It
Appropriate to Apply Porous Media Groundwater Circulation Models to
Karstic Aquifers?", by Peter W. Huntoon)
........The word "karst" is the German
form of the word "kras", which has been variously
translated as "bare, stony ground" or " a
bleak, waterless place". The term originated from the
geographic name for the landscape in the vicinity of Trieste, Italy,
and adjacent Slovenia, a limestone terrane where subsurface drainage
occurs through caves. Karst subsequently evolved as a descriptive
term for areas throughout the world with geomorphologic and
hydrologic characteristics similar to the Trieste karst.
Although the origin of the word is clear, there is
no universally accepted geologic definition of karst, and certainly
no hydrogeologic definition. Karst is most often used in a
geomorphologic sense to describe landscapes that result from
dissolution and subsurface drainage of carbonate terranes.......
This leads us to the definition proposed by
Huntoon:
Karst is a geologic environment containing soluble rocks with a
permeability structure dominated by interconnected conduits
dissolved from the host rock which are organized to facilitate the
circulation of fluid in the downgradient direction wherein the
permeability structure evolved as a consequence of dissolution by
the fluid.
If one gives some thought to this definition, it
drives home certain points:
-
soluble rocks are ubiquitous, therefore cave and
conduit systems are likely more common than one might deduce
from surface observation and
-
karst is all about the hydraulic gradient; saturated
cave/conduit systems evolve to connect high heads to low heads.
As a hydrogeologist, the definition of karst as
a landform or geologic process propagates the mindset that
karst problems are insurmountable, mysterious, or otherwise intractable. Adoption of a hydraulic definition such as the
one proposed by Huntoon, on the other hand, can inspire new ideas
for solutions, because it focuses on the important relationship
between karst and groundwater processes.§
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