Landslides, earthquakes, erosion... you've heard of these natural hazards and perhaps have even been affected by one of them. So what do engineering geologists have to do with natural hazards, anyway? Look at it this way - natural hazards are simply geologic processes that become hazardous when humans get in their way. For example, consider the natural process of "mass wasting", which is a generic term for the movement of soil and rock downhill in response to the pull of gravity. Mass wasting, which includes landslides among other things, is constantly occurring in mountainous and hilly terrain throughout the world. Yet, this natural process isn't much of a hazard until humans build something that gets in the way of a landslide.

Engineering geologists identify where geologic processes are most likely to have an adverse impact on humans, the structures we build, and the environment. They then work with a variety of technical professionals, land owners, regulatory agencies and other entities to prevent geologic processes from becoming "natural hazards." To learn more about natural hazards and their relation to engineering geology, check out the geologic
 hazards pages of the AEG web site by following the links below.

Landslides

Landslides occur throughout the world in response to natural processes like rainfall, earthquakes and coastal erosion, but can also be created by excavations and grading for roads, buildings, mines and other works. Our Landslide Hazards page provides information on the conditions that lead to landslides, and what can be done to avoid or mitigate slope stability problems.

Photo courtesy of Landslide Hazards






Earthquakes

When an earthquake occurs, it releases an immense amount of energy that can lead to various types of seismic hazards. What is the earthquake risk in your area? Our Earthquake Hazards page provides information how earthquake energy travels through the Earth and describes different earthquake-related hazards.

Photo courtesy of USGS








Tsunamis

The world was stunned on December 26, 2004 when the powerful Sumatra- Andaman earthquake triggered tsunamis that demolished many coastal areas of South and Southeast Asia.  Read more about the 2004 tsunami and other historical tsunamis such as those caused by the 1964 Alaskan earthquake.

Photo courtesy of the Department of Defense



Volcanoes

Most volcanoes occur along the boundaries of the Earth's crustal plates, where magma from within the Earth's crust reaches the surface. Did you know that different volcanoes form at different plate boundaries? What type of volcano produces an explosive eruption? Our Volcano Hazards page provides information on volcano classification and associated hazards.

Photo courtesy of USGS


Land Subsidence

Land subsidence is the result of loss of support within the subsurface soil and rock. Subsidence can result from groundwater and petroleum withdrawal and soil consolidation, but can also occur in areas of underground mining and soluble rock. Our Land Subsidence Hazards page provides information on the conditions that lead to land subsidence, and what can be done to avoid or mitigate such hazards.

Photo courtesy of The Physical Environment; from USGS Professional Paper 1401-A, "Ground water in the Central Valley, California- A summary report" Photo by Dick Ireland, USGS, 1977.





Erosion

Did you know that erosion by water is one of the most significant processes shaping the Earth's landforms? Erosion by streams and wave action transforms the Earth's surface, forming incredible natural wonders such as the Grand Canyon and constantly reshaping the world's beaches. However, this dynamic force can also impact our properties. Are you at risk for stream or coastal erosion? Our Erosion Hazards page describes the processes by which running water and waves cause erosion, hazards posed by eroding areas, and approaches to avoid or mitigate erosion hazards.

Photo courtesy of FEMA


Expansive and Collapsible Soils

Annually, expansive soils comprise the most expensive of geologic hazards. These clayey soils shrink and swell with changes in water content. Collapsible soils, which lose their strength when wetted, also cause significant structural damage. Our Expansive and Collapsible Soil Hazards page provides information on these soil hazards and what can be done to reduce your risk of property damage.
Photo courtesy of Soilstabilization.net




Other Hazards