Global View
Earthquakes are one of the most severe and dangerous natural hazards that humans face. With continued population growth and the new interconnectedness of a global economy, one major earthquake could kill upwards of a million people and cause fallout for global economies, including the U.S.
To learn more about earthquakes, I encourage you to visit the “Predicting Earthquakes” news story by the News Hour show of PBS. These are not required, but provided for your own interest. The story highlights the latest technology in earthquake prediction, and uses demonstrations and examples to discuss why earthquakes happen.
When the webpage opens, click the link in the gray box.
Within the United States, geologists have worked to classify faults for their earthquake potential. Geologists have not developed a single schema of when a fault is dangerous or not. The following example comes from the California Division of Dam Safety:
- Active Fault: An active seismic source is defined as a fault that has ruptured within the last 35,000 years.
- Inactive Fault: Contains geologic evidence and characteristics indicating lack of movement within the last 35,000 years
However, even inactive faults can move again. Generally, the longer period of time since the fault can be shown to have last moved, the lower the chance it will move again.
This bank of seismographs at the School of Mines at the University of
Nevada-Reno are operated by the U.S. Geological Survey. The seismographs
are recording data sent electronically from seismographs in the field. (Photo: T. Ashcroft/C. Thomas.)Please complete this section by taking the assessment.
