Using Google Earth to measure seacliff erosion rates

Alfred Hochstaedter, Monterey Peninsula College
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Initial Publication Date: June 13, 2013 | Reviewed: June 24, 2014


This lab uses Google Earth to measure the rate of seacliff retreat. It touches upon coastal processes, natural hazards, and coastal management issues. The central focus of the lab is in the Monterey Bay area.

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This lab activity is for an introductory Oceanography course. Most (~80%) of the students are taking the class for general education purposes. About 10% probably go on in some type of Earth Sciences.

Skills and concepts that students must have mastered

The students must be familiar with Google Earth and know how to manipulate it. In my class, the students do an Introduction to Google Earth in the lab previous to this one.

How the activity is situated in the course

It is situated in conjunction with a coastal field trip, where we see sites similar to the ones featured here. We talk about some of these concepts on the field trip. These seacliff retreat concepts are reinforced here with this lab.


Content/concepts goals for this activity

  1. Recognize that coastal erosion is happening on a human timescale that will affect buildings and places that they can see before them in their lifetimes.
  2. Measure the rate of coastal erosion.

Higher order thinking skills goals for this activity

  1. Apply quantitative skills to an issue that will continue to affect buildings that they can see on an every-day basis.
  2. Recognize that different bedrock surfaces erode at different rates.
  3. Recognize that some places along the coast are much more susceptible to erosion than others.

Other skills goals for this activity

  • Quantitative skills
  • Observational skills
  • Using Google Earth for something other than gawking at their neighbor's back yard.
  • Use and manipulate KML files in Google Earth.

Description and Teaching Materials

Students follow this lab to measure erosion rates at various places. At one place, where granite bedrock occurs, the coastal erosion rates are zero, or not measurable with these techniques. At other places, where the seacliff is composed of sand dune sand, the erosion rate is several meters over about 15 years.

Teaching Notes and Tips

Students will need help recognizing the top of the seacliff in Google Earth in order to draw a line along it.
Some students will need help manipulating KML files.


I have assessed student learning this activity by scoring the lab and then asking follow-up questions on tests and quizzes.

References and Resources

This USGS site is referenced in the activity. It has oblique aerial photographs of coastal regions taken before and after the last big El Nino.
"Rates and Trends of Coastal Change in California and the
Regional Behavior of the Beach and Cliff System", 2009

This is a nice overview article, more appropriate for instructor prep or advanced student use. I would not give this article to introductory students.