LIVING WITH SINKHOLES
CASE STUDY GROUP ACTIVITY: SCIENCE AND
ETHICS OF SINKHOLES
Cathy Pappas-Maenz
Department of Geology
Dawson College
WHAT IS A SINKHOLE?
• A hole in the ground which is not connected to
surface drainage.
• Sinkholes are typically found in a landscape
referred to as “Karst Topography”
• Soluble rocks such as limestone can be dissolved by
circulating groundwater producing caverns and
open spaces underground.
As the water infiltrates into the groundwater system and
encounters carbonate rocks like limestone, it may start to
dissolve the calcite in the limestone by the following
chemical reaction:
CaCO3 + H2CO3 = Ca+2+ 2HCO3-2
REGIONS AT RISK
20 percent of
the land surface
is karst and 40
percent of the
groundwater
used for drinking
comes from karst
aquifers
http://water.usgs.gov/ogw/karst/kig2002/jbe_map.html
KARST REGIONS OF THE WORLD
http://en.wikipedia.org/wiki/Karst
OVERVIEW OF THE ISSUES
• Natural earth processes, like floods, earthquakes,
landslides, and volcanic activity, and ground
subsidence are hazardous to people and property.
• A popular misconception claims that natural
disasters are getting more frequent and damaging,
but actually there are just more people and better
media coverage.
• To reduce risks to life and property, geologists try to
identify and analyze potentially hazardous
processes and take corrective measure to reduce
or even eliminate the hazard.
HAZARDS
1) Physical danger of
falling into them, as
well as the danger to
structures — buildings,
roads, etc.
2) Threat to ground
and surface water
quality by the
potential for direct
introduction of
contaminants.
http://www.cbc.ca/news/canada/montreal/sinkholeswallows-backhoe-in-downtown-montreal-1.1395574
http://water.usgs.gov/ogw/pubs/fs00165/
ROLE OF EARTH SCIENTISTS
Many natural disasters can be prevented and/or their
impact reduced.
• Sharing and communicating our knowledge more
effectively.
• Providing balanced information about risks and also
addressing inevitable uncertainties in natural hazard
mapping, assessment, warning, and forecasting.
• Raising awareness on the above issues and
promoting greater collaboration with urban
planners, policy makers and the public about
sinkhole risk that is needed to fulfill ethical
obligations.
CASE STUDY GOALS
• To introduce the basics of karst and cave origin,
with emphasis on geologic controls, interpretation,
and application to real world problems.
• How natural processes can affect the environment
• How human activities can affect the environment.
• Analysing and evaluating the difficulties involved
with policies and litigation resulting from sinkholes.
• Investigating who is responsible legally/ethically.
• Case Study
CASE STUDY: GUIDING QUESTIONS
After reading the scenario of the natural hazard, the
following set of questions need to be addressed:
• What facts are presented? (the known facts.)
• What ethical concerns do they raise?
• Which of the known facts are relevant to resolving the
ethical concerns?
• What additional facts might be relevant to the case?
(the unknown facts)
• How might these unknown facts affect what is ethically
at stake?
• What options are available?
• Which of these options seem best from an ethical point
of view?
LINKS TO THE CASE STUDY
Case study teaching notes
• http://sciencecases.lib.buffalo.edu/cs/collection/d
etail.asp?case_id=195&id=195
Follow-up to legal battle
• http://articles.baltimoresun.com/1998-1201/news/1998335117_1_sinkhole-genstar-knight
Additional references
• http://water.usgs.gov/ogw/karst/
• https://www.dnr.mo.gov/geology/geosrv/envgeo/s
inkholes.htm