Frequency of Large Earthquakes
Really large earthquakes, such as the ones that happened in Sumatra in 2004 or Japan in 2011 (both Mag 9.1), cause a lot of damage and loss of life. How often do such events occur globally? To answer this question, students process data obtained from the IRIS Earthquake Browser (IEB) tool to make a claim based on evidence. The IEB is a user-friendly data portal, and the task is straightforward, enabling students to practice accessing, downloading and manipulating real world data in spreadsheets and applying it to considering the societal resources needed to respond to major earthquakes.
Skills and concepts that students must have mastered
Learners should know what an earthquake is and something of the societal impacts they can cause. Familiarity with spreadsheets is required if learners will be downloading and manipulating data. However, a hard copy of the data is also provided.
How the activity is situated in the course
This activity can be used to engage learners in a unit about geologic hazards. This activity is particularly ideal to familiarize learners with the IRIS Earthquake Browser tool, prior to conducting more inquiry-based projects. A good follow-up activity is Exploring Rates of Earthquake Occurrence.
Content/concepts goals for this activity
- Describe the relationship between magnitude and frequency of earthquakes
- Understand the occurrence of large earthquakes cannot be predicted, but overall probabilities can be used for long term planning
Higher order thinking skills goals for this activity
- Making claims based on evidence
Other skills goals for this activity
- Accessing data in an online data portal and manipulating data in spreadsheets
- Communicating findings
Description and Teaching Materials
See attached file for instructor notes, NGSS alignment, links to supporting resources, student exercise, and answer key.
Frequency of Large Earthquakes Activity (Acrobat (PDF) 422kB Feb16 22)
- Answer key:
- Data file: IEB_export-Mag8-and-greater-1970-2021.csv (Comma Separated Values 4kB Nov17 21) - if students are not accessing the IEB portal themselves but you still want them to work with spreadsheet data
- Word versions of activity files: Frequency of Large Earthquakes WORD files (Zip Archive 780kB Nov18 21)
Teaching Notes and Tips
- This lesson can be accomplished in 1 to 2 class periods, depending on the options chosen for data processing. The task works well as an individual assignment, or group work, and can be easily adapted for distance delivery in a virtual learning environment.
- Although this exercise focuses on the largest earthquakes (Mag 8 and greater), smaller earthquakes (typically Mag 6-7) can also cause considerable damage depending on the local ground and human infrastructure conditions; they do affect a smaller region. The smaller more frequent earthquakes are also important to consider for planning societal planning. You may need to bring this up if students seem to be coming away with the idea that only the very largest earthquakes are important to think about.
Formative assessment of student understanding can be gathered from classroom observation and discussions with individuals or small groups.
The student exercise serves as the summative assessment for the activity. Some questions have clearly correct answers (see answer key). Instructors may choose to collect written answers to the questions, and evaluate with the provided key, or evaluate the students' understanding while they present their claims orally.
References and Resources
- IRIS Earthquake Browser (IEB) tool
- IRIS Earthquake Browser tutorial
- This activity is part of ANGLE Curricular Pathway 2: Plate Tectonic Setting.
- Contact ANGLE with questions or comments.