The following text is for questions 48 to 50.

    Sandstorms occur when winds strengthen to the point where they are able to lift grains of sand off the ground and blow them through the air. They tend to happen most frequently in sandy areas, such as deserts. For example, sandstorms are quite common in the Sahara Desert.

    Similar storms can arise in many areas around the world. When the top layer of soil consists primarily of dirt and rock rather than sand, these storms are usually called dust storms.

    Some people use the terms interchangeably, although one term or the other is usually more correct depending upon what type of particle is being blown about by the wind.

    For example, many dry, flat areas of the United States, such as Kansas, Oklahoma, Texas, New Mexico, and Arizona, experience dust storms and sandstorms frequently, especially during periods of drought. Moisture tends to hold particles to the ground, so dry conditions often lead to particles being picked up more easily by the wind.

    Areas of China, Mongolia, Africa, and the Middle East also often see these types of storms. Sandstorms and dust storms that result from microbursts or downbursts from thunderstorm cells are often known by a special name: haboob. This name comes from the Arabic word habb, which means "wind".

    Sandstorms can arise quickly and without much warning. Wind speeds as low as 25 miles per hour can cause sandstorms, so it doesn't take hurricaneforce winds to get sand particles moving through the air. The faster the wind blows, the higher and farther the particles can be blown.

    Sandstorms can be very dangerous. Since they can reduce visibility to near zero, sandstorms make traveling difficult. Blowing sand and dust particles can also find their way into the tiniest cracks and crevices in machinery, causing frequent mechanical breakdowns.

    Sandstorms can also pose a variety of health problems, since sand and dust flying through the air can find its way into your eyes, nose, mouth, and lungs. During a sandstorm, people should wear some type of mask that will filter out these particles.

(Adopted from: https://wonderopolis.org/wonder/what-causes-sandstorms (April 26, 2019))

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