C A S E S T U D Y G R O U P A C T I V I T Y: S C I E N C E A N D E T H I C S O F S I N K H O L E S

LIVING WITH SINKHOLES

Cathy Pappas-MaenzDepartment 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://water.usgs.gov/ogw/pubs/fs00165/

http://www.cbc.ca/news/canada/montreal/sinkhole-swallows-backhoe-in-downtown-montreal-1.1395574

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/detail.asp?case_id=195&id=195

Follow-up to legal battle• http://

articles.baltimoresun.com/1998-12-01/news/1998335117_1_sinkhole-genstar-knight

Additional references• http://water.usgs.gov/ogw/karst/• https://

www.dnr.mo.gov/geology/geosrv/envgeo/sinkholes.htm