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Natural hazards

A natural hazard is any natural event that poses a risk to humans or the environment. Some natural hazards, such as severe weather events, can be predicted using data and technology. Other hazards, such as earthquakes, are not yet predictable. Created by Khan Academy.

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  • duskpin tree style avatar for user Can't leave empty.
    Is it possible for a tornado and a hurricane to be at the same spot?
    (7 votes)
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  • hopper cool style avatar for user adenwillis
    A volcano
    (0 votes)
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  • male robot donald style avatar for user Noah
    while she sets up an emergency kit for losing power here in South Africa between 25 and 50 percent of the day we have no power do to our providers sucking I general and not having the money to give us electricity all day
    (4 votes)
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  • duskpin ultimate style avatar for user dewdropfox
    Is hazard the same as disaster?
    (3 votes)
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  • blobby green style avatar for user Leilani
    Hi thank you so much you are so helpful
    (3 votes)
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  • hopper jumping style avatar for user J. Giesbrecht
    Meh, us in Canada, we're used to six feet of snow and negative 40. When it gets negative 30, we usually break out the beach umbrellas and sunscreen. Go Canadians!
    (3 votes)
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  • piceratops seedling style avatar for user MONSTER
    You help me a lot
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  • blobby green style avatar for user Liu Keke
    I kind of understand now why Japanese wanted to intrude China before... Boy, Japan is between two tectonic plates.(Yep, earthquake every day) And full of active volcanos! Gee, I glad that I'm a Shanghainese!
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    2 D
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Video transcript

- [Instructor] Before I go to a new place, I try to do some thorough research about it. What do I want to do there? What's the weather forecast? What's the chance that it might erupt? I learned this hard way recently. While preparing for a trip to Mount Rainier National Park, I somehow missed that the mountain itself is actually a volcano. Though it hasn't erupted in over a century, it has the potential to do so again, something that it would have been nice to know more than a week before I left for my vacation. Volcanoes are one of the most dramatic examples of a natural hazard, a naturally occurring phenomenon that can pose risks to humans and society. Natural hazards can be very dangerous for our communities. But scientists can help people better understand the risks that may occur where they live so everyone can work together to prepare safety guidelines. Different places experience different natural hazards due to local geographic or atmospheric conditions. For example, a storm on open plains could spawn a tornado. Similarly, a storm over the ocean could grow into a hurricane or a cyclone by the time it reaches the coast. These coastal rainstorms, along with their colder counterparts, blizzards, are the main natural hazards that I may run into where I live in the mid-Atlantic. Too much rain or snow can be dangerous, of course, but scientists have gotten pretty good at predicting weather conditions. Meteorologists use all kinds of technologies to map where and when a storm may form. Orbiting satellites can take pictures of cloud patterns from above. Weather stations back on the surface can use electromagnetic wave fields measured through Doppler radar to determine how heavy rain is falling or how strong the wind is blowing in those same clouds. They feed all of this and other data into computer models that can help them predict if the storm is severe enough to become a natural hazard. For example, this map from the National Oceanic and Atmospheric Administration's Weather Prediction Center shows where people can expect rainstorms, where others can expect snowstorms, and where those storms may become powerful enough to pose risks. Despite great advances in our ability to predict natural hazards, there are some phenomena that are less predictable, which can make them harder to prepare for. You see, the outer part of Earth is made up of large moving pieces called tectonic plates. These plates can grind or slip against each other, releasing energy in the form of seismic waves. Most of the time, we don't even notice these tectonic movements. But especially along boundaries or fault lines in the plates, people may experience the ground-shaking tremors of earthquakes. Earthquakes can be especially dangerous in highly populated areas where they damage buildings, roads, and other forms of human infrastructure. Earthquakes are often associated with volcanic activity, since volcanoes are often found near boundaries and fault lines of the tectonic plates. As the plates move and magma swells up to the surface, volcanic eruptions can release everything from clouds of gas or ash to rivers of molten lava. An earthquake in one location may even agitate large bodies of water enough to generate a tsunami, a huge and powerful wave, along the coastline in another. Tsunamis can affect the local region as well as regions far away. Scientists can't predict an intense earthquake, volcanic eruption, or tsunami as effectively as they can a severe weather event. But they are working to better understand Earth's seismic activity and when it poses a risk. For example, they use tools like seismographs to determine when an earthquake is happening and its strength or magnitude. Data from both minor and major tremors may help scientists figure out the signs that an earthquake is coming, giving communities along fault lines an early warning to evacuate or brace themselves, rather than simply reacting to the aftermath. Engineers can even use the data they've recorded from past earthquakes to design buildings and other structures to withstand the effects of future ones. Communicating what they've learned may help places that experience seismic natural hazards to prepare far in advance, further reducing the risks that they face. Natural hazards can cause a lot of harm. But scientists are learning more every day about why they occur and how communities can remain resilient. For my trip, I studied up on visiting a volcano zone and was relieved to find that there's been no signs that Mount Rainier's erupting any time soon. The whole experience really reinforced the importance of being prepared. Even if natural hazards aren't common where you live or travel, having a preparedness plan can help you stay safe in a scary situation. These are just some examples of how scientific research benefits society. Now, if you'll excuse me, I'll be setting up an emergency kit for the next time I lose power during a storm.