Japan Earthquakes & Tsunami

We're going to do our report on natural disasters in Japan. Japan has had trouble with many different natural disasters, and we are going to talk about the most common ones. The most common natural disaster is earthquakes. Japan can have up to 5000 earthquakes each year. Earthquakes can also form tsunamis, which are large waves that crash up against the shore and can wash away people, buildings, and bridges.

One other disaster is a volcanic eruption. There are many volcanoes in Japan that are still live. A volcanic eruption can pour ash and lava all over the city. This can be a big disaster.

We will also be talking about typhoons. Typhoons in Japan come in August, when it hits the heavy rain season. Typhoons can bring wind and rain that causes much damage, including landslides and floods.

In the following chapters, We will talk about these different natural disasters, and we'll share examples of each disaster that have occurred in Japan over the past years.

EARTHQUAKES

Earthquakes are the most common natural disaster in Japan. Japan has continuous earthquake activity because of it's position. It sits on a subduction zone, which is where one plate is being forced beneath another. It is also at the meeting point of two pieces of the giant Pacific plate, which are moving in different directions along side each other. In Japan, hardly a day will go by without an earthquake. Most of these earthquakes are very minor, though every year there are a few that are strong.

The fact that homes and buildings were built so close to each other and were made of paper and wood and that open fires were used for lighting, cooking, and heating a long ago made it easy for fires to start during earthquakes. The damage would be terrible.

The worst earthquake of modern days struck in Tokyo and Yokohama on September 1, 1923. The quake ruined several hundred thousand homes and buildings, the fires that followed caused more damage. In this earthquake, more than one hundred and forty thousand people were killed. The heat of the fires was so bad that it caused tornado-like winds. One large group of people that were in a shallow lake around Asakusa of Tokyo died when the fierce winds and fires sucked all the oxygen out of the air around them.

Today, Japan has strict building codes to make them stand up better in earthquakes. The Government has also organized disaster-prevention and relief measures.

More recently, at the time of the first anniversary of the moment magnitude (M.W.)6.7 1994 Northridge (California) Earthquake, Kobe, Japan was hit by an M.W. 7.2 earthquake. The date was Tuesday, January 17, 1995. Both earthquakes struck in the pre-dawn hours, both began beneath densely populated areas and both caused horrible damage, though in Kobe there were a lot more deaths and financial losses. In Japan, earthquakes are measured with a shindo scale. It is the same as the Richter scale we use. "Shin" means "to shake" and "do" means "degree". The Kobe quake therefore measured 7.2 shindo.

Kenji Rikitake, a Japanese citizen who reported over the Internet all that was happening during the days following the quake said, "the morning video clips near Sannomiya station were really eerie. Incredible silence. Voice over of the announcer, rubble crunching underfoot. Occasionally punctuated by voices of rescue workers."*


TSUNAMIS

A tsunami is another natural disaster. They occur in Japan for two reasons, one because Japan is surrounded by water. Two, because Japan has a lot of earthquakes which cause tsunamis.

A tsunami is a tidal wave. When a tsunami approaches shore it starts to slow down and grow in height. Like other water waves, tsunamis start losing energy as they get closer to shore. Some of the water energy is bounced off shore. Though this happens tsunamis still reach the coast with major amounts of energy. Tsunamis can strip beaches of sand that might have taken years to form there. They can also suck up trees and other plants. Tsunamis are capable of flooding hundreds of meters of land. Tsunamis can crush homes and structures along the coast. The tsunamis' height can reach up to 10, 20, and even 30 meters.

One tsunami took place in Hokkaido on July 12, 1993 at 17 minutes past 10 p.m.. A 7.8 earthquake occurred off the west coast of Hokkaido in the Sea of Japan. The earthquake formed a tsunami which hit the coast line of nearby Okushiri Island and the central west coast of Hokkaido within minutes. There was an estimate of $800 million in property loss. Over 120 people were killed in Japan by the tsunami.

In the next few pages I will show some pictures of what happened in the Hokkaido tsunami. These pictures were taken by Commander Dennis J. Sigrist, acting Director of the International Tsunaimi Information Center, Hawaii.

Steps were installed for residents to easily walk between the housing area on the bluff ( not visible) and the community area near the sea. Many residents remembered the May 1983 earthquake and tsunami and used this previous to escape the deadly tsunami waves in 1993, using the steps as the fastest way to safety.

Battery operated clocks were found scattered in the mess and provide a rough estimate of the approaching time of the destructive waves. The salt water shorted the clocks batteries. This clock shows a travel time of fifteen minutes following the earthquake.

A fishing boat is beached near a damaged fire truck.

These boats were beached up into a seafood processing plant.

The village of Monai, west Okushiri Island. The place was completely destroyed by the tsunami. Ten people were killed and twelve houses were destroyed.