Earthquake prediction has long been a challenge for scientists around the globe since the geological phenomenon can occur at any time and any location with little or no warning. The chance of a powerful earthquake can only be determined through long-term forecasts in a general area or region on Earth.

Throughout history, no individual or group has yet successfully predicted a major earthquake: including its date and time, location and magnitude. These are the three elements essential to make an earthquake, according to the United States Geological Survey (USGS). While small earthquakes occur all the time, high-intensity earthquakes are rare but is something to watch out.

Now, a new study led by researchers from Pennsylvania State University found a potential solution to the dilemma of earthquake forecast: ancient underthrust rocks. Rocks buried deep in ancient subduction (俯冲) zones — where tectonic( 地壳的) plates bump with each other — could help scientists make better predictions of how these zones behave during the years between major earthquakes.

According to the USGS, we are still uncertain how we can make such a feat and are not expecting to perfectly predict major earthquakes any time in the foreseeable future.

Although some people in the past said they could predict earthquakes, the U.S. Government agency asserts these are all failed predictions. Their predictions are neither grounded on scientific fact nor passed through the scientific method.

Since authorities in the field of geology and other related areas acknowledged that earthquake prediction is still far from being completed, scientists continue to further understand this mystery. Unlike weather forecasts of hurricanes and other storms, earthquakes have no concrete parameters (参数) that would indicate that they would occur in the coming hours, days, weeks or months.

Regardless, the Penn State researchers have made progress in the dilemma by understanding the underthrust rocks in ancient subduction zones. Determining this area could help scientists better predict the behavior of these zones during periods between major earthquakes. Evidence of their findings was based on clues from rock formations in Alaska and Japan.

Rivers are very important. Humans rely on them for food and water. But rivers can destroy things, too. They can flood, or rise over their banks, making the water run into the nearby land. Floods can also kill humans and wildlife. However, floods are not always bad. Some ecosystems need them every once in a while.

Flooding can not only drown animals but also destroy habitats. For example, a flood in India in 2012 killed many one-horned rhinos. Flood waters can pick up dirt from riverbanks, which makes the water dirty. Too much dirt will clog rivers and streams, preventing the river from flowing. Sometimes flood waters can carry pollution to the sea and harm marine life. In addition, flood waters can carry disease, including hepatitis A (甲型肝炎) and cholera (霍乱).

However, not everything about floods is bad. Sometimes they bring new life to ecosystems. Flood waters carry nutrients to the nearby land. Over time, the water dries up and leaves behind particles (微粒) of dirt and mud. The particles are called sediment (沉淀物) which can be good due to its ability to improve the dirt and help plants grow. Floods are important to some animals as well. For instance, some animals see floods as a sign that it is time to mate or migrate. Floods leave sediment on river beds where baby fish can grow and carry nutrients for small animals in the water to eat. Moreover, in dry seasons, water might dry up, but floods help refill the wetlands, keeping the ecosystem going.

Floods are a part of nature. They can destroy living things and the environment. But some ecosystems need floods to survive.

My name is Ben. I am 13, and I live in Chantilly, VA. Just yesterday, June 24, I was at home watching my sister, who is mentally handicapped (弱智的). My father was at work while my mother and younger sister were at my mother’s office.

I had noticed the clouds growing darker and the ones to the east were turning green. At first I thought nothing of it, but then on TV, the weather reporter was announcing a big thunderstorm warning, one that usually brings hail (冰雹) and heavy rain.

After seeing that, I called my mother and told her about it. She told me I should not be worried because it was just a thunderstorm so we hung up. Then I looked outside and noticed it was almost pitch black at 4：30. I took a flashlight (手电筒) because I was sure the power was going to go out any second.   Then no sooner had I gotten back from getting the flashlight than the weather reporter announced a Tornado Warning! I had never been in an actual tornado before, but I had seen some funnel clouds before in Montana.

Suddenly I realised I had no time to lose and I had to try to get my sister down the stairs to the basement in a matter of minutes. I surprisingly got her down there with no trouble at all and I raced back up the stairs to get the cordless phone. When I got back downstairs my dad called and told me to get downstairs immediately. I told him I was already down there! He said OK and we talked for a few seconds and then we hung up. Then_through the basement windows, the only thing_I_could_see_was_lightning.

I do not recall hearing of any deaths, or too many injuries so I guess everyone got a good head start to run to their basements. Either that or we are all lucky.