Hazards 101

Although both are sea waves, a tsunami and a tidal wave are two different and unrelated phenomena. A tidal wave is a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth ("tidal wave" was used in earlier times to describe what we now call a tsunami.) A tsunami is an ocean wave triggered by large earthquakes that occur near or under the ocean, volcanic...

Vog poses a health hazard by aggravating preexisting respiratory ailments. Sulfur dioxide (SO2) gas can irritate skin and the tissues and mucous membranes of the eyes, nose, and throat, and can penetrate airways, producing respiratory distress in some individuals. Aerosol particles in vog can also penetrate deep into human lungs and, at elevated levels, can induce symptoms of asthma. Physical...

Our technology based infrastructure can be adversely affected by rapid magnetic field variations. This is especially true during “magnetic storms." Because the ionosphere is heated and distorted during storms, long range radio communication that relies on sub-ionospheric reflection can be difficult or impossible and global-positioning system (GPS) communications can be degraded. Ionospheric...

If you are INDOORS -- STAY THERE! Get under a desk or table and hang on to it (Drop, Cover, and Hold on!) or move into a hallway or against an inside wall. STAY CLEAR of windows, fireplaces, and heavy furniture or appliances. GET OUT of the kitchen, which is a dangerous place (things can fall on you). DON'T run downstairs or rush outside while the building is shaking or while there is danger of...

No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. USGS scientists can only calculate the probability that a significant earthquake will occur (shown on our hazard mapping) in a specific area within a certain number of years. An earthquake prediction must define 3 elements: 1...

There are 161 potentially active volcanoes in the United States. According to a 2018 USGS assessment, 57 volcanoes are a high threat or very high threat to public safety. Many of these volcanoes have erupted in the recent past and will erupt again in the foreseeable future. As populations increase, areas near volcanoes are being developed and aviation routes are increasing. As a result, more...

Debris flows are fast-moving landslides that are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. They occur in a wide variety of environments throughout the world, including all 50 states and U.S. Territories. Debris flows generally occur during periods of intense rainfall or rapid snowmelt and usually start...

You can get an idea as to how concerned you should be about radon in your house by learning about the geology of the site and its radon potential. If your house is in an area the Environmental Protection Agency (EPA) shows has a high potential for radon, then chances are that your house may have an indoor radon problem. However, the way a house is built can increase the risk - so even in areas of...

Chronic wasting disease (CWD) has an extended incubation period averaging 18–24 months between infection and the onset of noticeable signs. During this time frame animals look and act normal. The most obvious sign of CWD is progressive weight loss. Numerous behavioral changes also have been reported, including decreased social interaction, loss of awareness, and loss of fear of humans. Diseased...

The U.S. Energy Information Administration estimates that in 2019, the United States emitted 5,130 million metric tons of energy-related carbon dioxide, while the global emissions of energy-related carbon dioxide totaled 33,621.5 million metric tons.

Earthquakes can strike any location at any time, but history shows they occur in the same general patterns year after year, principally in three large zones of the earth: The world's greatest earthquake belt, the circum-Pacific seismic belt, is found along the rim of the Pacific Ocean, where about 81 percent of our planet's largest earthquakes occur. It has earned the nickname "Ring of Fire". Why...

The Earth's outer core is in a state of turbulent convection as the result of radioactive heating and chemical differentiation. This sets up a process that is a bit like a naturally occurring electrical generator, where the convective kinetic energy is converted to electrical and magnetic energy. Basically, the motion of the electrically conducting iron in the presence of the Earth's magnetic...