Tags Natural Hazards

Tag: Natural Hazards

Tornadoes – Introduction

A tornado is a violently rotating column of air, pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud.

Winter Storms/Extreme Cold – Vulnerability Assessment

To assess your vulnerability to the threat of a Winter Storm or Extreme Cold event to your family and property, perform an assessment to determine if you have knowledge of, are prepared and/or have a plan by answering certain questions.

Winter Storms/Extreme Cold – Aspects and Features

Winter storms can range from a normal snow over a few hours to a blizzard with blinding, wind-driven snow that lasts for several days. Many winter storms bring dangerously low temperatures and, sometimes, strong winds, icing, sleet, and freezing rain. Moreover, serious health problems can result from prolonged exposure to the cold such as hypothermia and frostbite.

Winter Storms/Extreme Cold – Types and Classifications

A winter storm is an event in which varieties of precipitation are formed that only occur at low temperatures, such as snow or sleet, or a rainstorm where ground temperatures are low enough to allow ice to form (i.e. freezing rain).

Extreme Heat – Introduction

Heat kills by pushing the human body beyond its limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.

Extreme Heat – Aspects and Features

Heat is the number one weather-related killer in the United States, resulting in hundreds of fatalities each year. Conditions involving high air temperatures, radiant heat sources, high humidity, direct physical contact with hot objects, or strenuous physical activities have a high potential for causing heat-related illness. Other conditions that contribute to heat-related illnesses include stagnant atmospheric conditions and poor air quality.

Extreme Heat – Types and Classifications

People suffer heat-related illness when their bodies are unable to compensate and properly cool themselves. The body normally cools itself by sweating. But under some conditions, sweating just isn't enough. In such cases, a person's body temperature rises rapidly. Very high body temperatures may damage the brain or other vital organs.

Severe Thunderstorms – Types and Classifications

About 10 percent of thunderstorms are classified as severe—one that produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.

Severe Thunderstorms – Associated Hazards

Hazardous weather conditions can be packed into very concentrated zones in and around thunderstorms. Hazards include high winds, straight-line winds, large hail, icing, lightning, tornadoes, heavy rain and poor visibility.

Severe Thunderstorms – Introduction

Thunderstorms affect relatively small areas when compared with hurricanes and winter storms. The typical thunderstorm is 15 miles in diameter and lasts an average of 30 minutes. Despite their small size, ALL thunderstorms are dangerous!

Cyclones (Tropical) – Vulnerability Assessment

To assess your vulnerability to the threat of a Tropical Cyclone to your family and property, perform an assessment to determine if you have knowledge of, are prepared and/or have a plan by answering certain questions.

Floods – Links and Resources

USGS Flood Watch The USGS FloodWatch website is a map-based resource from USGS WaterWatch that gives users hourly visual updates for flood conditions at over...

Floods – Types and Classifications

You may already know that a flood is the rising and overflowing of a body of water onto normally dry land. But, did you know that there are several different types of floods?

Floods – Introduction

Floods are one of the most common hazards in the United States. Flood effects can be local, impacting a neighborhood or community, or very large, affecting entire river basins and multiple states.

Earthquakes may be more likely during New and Full Moons

When the sun, moon and Earth are aligned, high tidal stress may increase the chances that an earthquake will grow bigger than it otherwise might have been.

Cyclones (Tropical) – Links and Resources

Related links and resources for Tropical Cylone and Hurricane hazards, disasters and incidents.

Cyclones (Tropical) – Associated Hazards

While most people know that tropical cyclones can contain damaging winds, many do not realize that they also produce several other hazards such as: tropical cyclones are storm surge, flooding, and tornadoes.

Cyclones (Tropical) – Types and Classifications

Depending on the strength of the winds in the circulation, tropical cyclones are further divided into tropical depressions, tropical storms, and hurricanes. When tropical cyclones reach hurricane strength, they become classified by wind speed.

Cyclones (Tropical) – Aspects and Features

The main parts of a tropical cyclone are the rainbands, the eye, and the eyewall. Air spirals in toward the center in a counter-clockwise pattern in the northern hemisphere (clockwise in the southern hemisphere), and out the top in the opposite direction.

Cyclones (Tropical) – Introduction

A hurricane is a type of tropical cyclone that is a warm-core, low pressure system without any "front" attached, that develops over the tropical or subtropical waters, and has an organized circulation.

Tsunamis – Vulnerability Assessment

The largest source region for tsunamis is in the Pacific Ocean with 71% of all occurrences. The remaining occurrences of tsunamis happen in the Mediterranean Sea (15%), Caribbean Sea and Atlantic Ocean (7%), Indian Ocean (6%), and finally the Black Sea (1%). Of all tsunamis, 83% are produced directly by earthquakes.

Earthquakes – Vulnerability Assessment

Levels of earthquake preparedness and disaster resilience determine how vulnerable people are to seismic hazards. In any geographic area, three main factors together determine earthquake hazard vulnerability: the strength and/or duration of the seismic hazard, the proximity of people and property are to the hazard, and the number of people and amount of property that are exposed to the hazard.

Volcano Hazards Program

The USGS Volcano Hazards Program monitors active and potentially active volcanoes, assesses their hazards, responds to volcanic crises, and conducts research on how volcanoes work.

Earthquake Hazards Program

The USGS Earthquake Hazards Program is part of the National Earthquake Hazards Reduction Program (NEHRP), established by Congress in 1977. They monitor and report earthquakes, assess earthquake impacts and hazards, and research the causes and effects of earthquake.

Tsunami Warning Program

The Pacific Tsunami Warning Center (PTWC) is one of two tsunami warning centers that are operated by NOAA in the United States. The West Coast and Alaska Tsunami Warning Center (WCATWC) is the second of the two tsunami warning centers.

What is a Natural Hazard and a Natural Disaster?

A natural hazard can be defined as a threat of a naturally occurring event (flood, tornado, hurricane, volcanic eruption, earthquake, heat-wave, landslide, etc.) that can have a negative effect on people, property or the environment.

Are you prepared for a disaster?

According to Ready.gov, 1 in 4 families have not planned for emergencies and only 40% know how to plan. Being prepared, having a plan and understanding what to do is the best protection, is your responsibility and can reduce fear, anxiety and losses that accompany disasters.

Winter Storms/Extreme Cold – Links and Resources

Related links and resources for winter storms and extreme cold temperatures.

Wildfires – Links and Resources

Related links and resources for volcanoes and volcanic eruptions.

Wildfires – Introduction

Wildfires may begin in the wildland-urban interface or in remote spots where nobody notices them and then spread quickly, igniting brush, trees, and buildings. An increasing number of people are choosing to live in woodland settings, in or near forests, rural areas, or remote mountain sites.
Wedge Tornado Binger. OK 1981

A ‘wedge’ tornado in Binger OK, on 22 May 1981. ‘Wedge’ is informal storm observers’ slang for a tornado which looks wider than the distance from ground to ambient cloud base. Although many famous ‘wedge’ tornadoes have also been violent, producing EF4-EF5 damage on the Enhanced Fujita scale, a tornado’s size does not necessarily indicate anything about its strength.

How a tornado forms

Graphical representation of the wind and thunderstorm conditions that create a tornado.

Tornado Frequency 2003-2012

This intensity map represents the amount of days per year with a reported tornado between 2003 and 2012.