What is a hurricane?

    You may already know that hurricanes are storms that can cause devastating(毁灭性的)waves, wind, and rain. They happen during “Hurricane Season,” which is from June 1st until November 30th in the Atlantic Ocean and from May 15th until November 30th in the Pacific Ocean.

Categories(类别)of Hurricanes

    There are five categories of hurricanes, which are based on wind speeds. The categories help people know how much damage(危害)a hurricane may cause because the greater the wind speed, the more dangerous the storm is. For example, a Category 5 hurricane has winds over 155 miles per hour, which are strong enough to destroy the buildings along the shorelines completely.

Hurricane Dangers

When a hurricane happens together with heavy rainfall, there can be a devastating flood. The centre of a hurricane is called the eye. While most of a hurricane has dangerously strong winds, the eye is actually(事实上)a calm area in the storm. When the eye of a hurricane passes over land, people might think that it's over, but before long the wind and rain increase again as the second part of the hurricane moves through.

Hurricane Safety Tips

    There is no way to stop a hurricane or make it change direction, so if you ever find yourself in the path of a hurricane, be sure to remember the following safety tips.

    Be sure you have a radio, batteries, fresh drinking water, and enough food.

    Tell neighbours, friends, and family members your emergency plans. Tell them where you'll go if you need to leave your home.

    If you live near the ocean, leave your home and travel to a safe place. You could stay with a friend or a family member, in a hotel or in an emergency shelter area.

    Stay inside during the storm. You could be seriously injured (受伤) if you go outside.

    Many environmental groups are warning that oceans of the world are in great danger. In the past 50 years, the number of water with zero oxygen(氧气) in the open ocean has increased more than four times. In the near coast water bodies, including the river mouth and seas, low-oxygen areas have increased more than 10 times since 1950.Scientists discover that oxygen continues dropping ever outside these zones as the Earth warms. To stop the drop, the world needs to control in both climate change and nutrient(养分) pollution.

    Oxygen is a must to life in the oceans. The drop in ocean oxygen is among the most serious effects of human activities on the Earth's environment.

    This is the first time for the scientists to take such a deep look at the causes, results and solutions to low oxygen worldwide, in both the open ocean and the near coast waters. About half of the oxygen on Earth comes from the ocean. However, mixed effects of nutrient loading and climate change are greatly increasing the number and size of "dead zones" in the open ocean and the near coast waters, where oxygen is too low to support most sea life.

    In the areas traditionally called "dead zones", like those in Chesapeake Bay and the Gulf of Mexico, oxygen drops to levels so low that many animals have trouble in breathing and die. As fishes run away from these zones, their living areas become smaller and smaller. But the problem goes far beyond "dead zones". Even smaller oxygen drops can hold up the growth in animals and lead to disease or even death. Low oxygen also can cause the release of dangerous chemicals. Although a few animals can grow well in dead zones, overall biodiversity(多样性)falls.

    Hello, my name is Clock. I have a round face. I have three hands. One hand is short, and two hands are long. I don't have arms, but my hands can turn(转动)round and round. I don't have legs, but I can walk(走路). I don't have a mouth, but I can speak. I can wake you up(叫醒). Do you know me? Who am I? Please guess!