Claire Chadwick; Lauren Maurizio; Robin Humphreys; and Vijay Vulava
Fundamentals of Earthquakes
Deformation and tectonic activity in Earth’s crust fractures rock creating geological faults. Any movement along these faults causes a release of energy causing enormous damage to Earth’s surface and directly impacting life on Earth.
The video below provides a short overview of earthquake hazards. As you watch the video, take notes.
Exercise 1 – Introduction to Earthquakes
Use the resources below to answer the following questions:
- 9 Crustal Deformation and Earthquakes – An Introduction to Geology (opengeology.org)
- FAQs by Category (usgs.gov)
- Lists, Maps, and Statistics (usgs.gov)
- In which three regions of the Earth do 80% of earthquakes occur?
- What causes earthquakes?
- What causes earthquake-inducing stress in most cases around the world?
- The three regions where 80% of earthquakes occur are associated with tectonic boundaries. True/False
- Currently, what scale is used to accurately measure earthquake strength?
- The moment magnitude scale has an upper limit. True/False
- The energy released from an earthquake is brought to the surface of the Earth in the form of ___.
- Match the surface location and depth of an earthquake to the terms Epicenter and Hypocenter.
- What instruments are used to measure earthquakes?
- When an earthquake occurs on land in populated areas, what type of damage occurs?
- Describe two ways communities have adapted to earthquake-prone areas to protect themselves.
Now, let’s investigate how we can look up technical information about earthquakes. The US Geological Survey (USGS) is one of the oldest and largest national institutions that is tasked by the US Congress to study Earth’s resources, hazards, and environments. They have an active network of scientists and advanced technology to study hazards such as earthquakes. The Earthquake Hazards (usgs.gov) program serves as the largest gateway to the latest and historic information about earthquakes in the US and the rest of the world. You will use the exercise below to familiarize yourself with information from this resource.
Exercise 2 – The Largest Recorded Earthquake
Use the USGS resources below to investigate the largest recorded earthquake on Earth and answer the following questions:
- In which country did the strongest recorded earthquake occur?
- What was the magnitude of this earthquake?
- Where was the epicenter? (Report as Latitude Longitude, e.g., CofC Cistern is 32º47’N 79º56’W)
- Where was the hypocenter? (Report in km depth)
- What were the major causes for the loss of life and property?
- How can you tell if such intense earthquakes are normal or unusual to this region of the world?
