6 - Coastal disasters


Coastal areas are particularly susceptible to geological disaster whether they are tectonically active or not. Some coastal disasters happen fast and others are slowly ongoing but just as damaging. We will discuss the most abrupt and therefore the ones directly dangerous to human life first and get to the less dangerous ones at the end of the unit. Tsunami are the most impressive and they usually have a geological origin so we will spend quite a bit of time on them but we will also discuss sea-level rise and land subsidence as well as the impact of large storms in the coastal zone.

Learning Objectives

When you have finished the work for this unit, you should be able to:

1.  Describe waves based on the parameters of wave height, wave period, wave velocity and wavelength.
2.  Know the differences between normal ocean waves and tsunami using wave parameters.
3.  Discuss the properties of tsunami in deep water and how they are transformed upon reaching coastal shallows
4.  Describe how and where earthquakes generate tsunami
5.  Understand the plate tectonic environment and processes that led to the tsunami of Dec. 26, 2004.
6.  Explain the various volcanic processes that can cause tsunami.
7.  Explain how major slope failures can cause tsunami and where this is likely to happen in the future.
8.  Explain how tsunami warning systems work and how they could be made more effective.
9.  Understand how and where land subsidence occurs in coastal areas.
10. Understand the factors that affect global sea level change.
11. Understand the dangers associated with tropical storms in coastal areas and which geological environments are at     greatest risk.
12. Use the Saffir-Simpson Scale to classify tropical storms.
13. Evaluate various methods used to reduce erosion along vulnerable coasts.

Required Readings

Abbott, P.L., 2014. Natural Disasters, Ninth Edition:

Readings From the Old Book

Abbott, P.L., 2012. Natural Disasters, Eighth Edition:

Glossary Terms

Archimedes Principle Ice Shelf
Ash IPCC (Intergovernmental Panel on Climate Change)
Aswan Dam IUGS (International Union of Geological Sciences)
Atmospheric Pressure Jetty
Barrier Island Lagoon
Basaltic Lava Larsen B Ice Shelf
Breakwater Levee
Caldera Microplate
Coastal Marsh NOAA (National Oceanic and Atmospheric Administration)
Constructed Levee Peat
Continental Shelf Phreatic Eruption
Delta Pumice
Epicentre Pyroclastic Flow
Eustatic Change Seismograph
FEMA (Federal Emergency Management Agency) Shield Volcano
Floodplain Storm Surge
Floodwall Subduction Zone
Greenland Ice Cap Thermal Expansion
Groin Tsunami 
Hurricane Water Table
Ice Floe