Tag Archives: tsunami genesis

Small hilltop city becomes refuge for earthquake and tsunami survivors

In the aftermath of the earthquake that violently struck Japan and the tsunamis it generated, the small, industrial city of Hitachi emerged unscathed from what Prime Minister Naoto Kan has described as Japan’s “worst crisis since the Second World War”, making it somewhat of a refuge for the hordes of refugees that flooded from many parts of the country.

How the city managed to escape unharmed from the seismic disaster is credited to its topography – basically the city was built on some a higher ground. The Friday temblor, which ravaged the entire country and created several aftershocks and tsunamis is estimated to have killed at least 10.000 people, and will probably cause additional deaths. In Hitachi, however, things are very different.

“We were so lucky really. I haven’t heard of any serious injuries amongst people I know,” says a security guard keeping watch outside the Hitachi Futo shipping company’s lot in the city’s harbor.

As aftershocks and tsunamis continue to rattle the area, more and more people continue to move to this lucky town – several thousands of refugees are now literally at the gates of the city, waiting and hoping for shelter, and a steady roof above their heads.

Israel, in danger of being hit by tsunamis

tsunami3Dr. Beverly Goodman of the Leon H. Charney School of Marine Sciences at the University of Haifa was doing some research on the ancient port and shipwrecks of the place, when she stumbled upon information that led her to this conclusion.

“There is a likely chance of tsunami waves reaching the shores of Israel. Tsunami events in the Mediterranean do occur less frequently than in the Pacific Ocean, but our findings reveal a moderate rate of recurrence.”

“We expected to find the remains of ships, but were surprised to reveal unusual geological layers the likes of which we had never seen in the region before. We began underwater drilling assuming that these are simply local layers related to the construction of the port. However, we discovered that they are spread along the entire area and realized that we had found something major”

What they did is they drilled at various depths and proceeded to date the layers they found, using two methods: everybody’s friend carbon-14 dating and OSL (optically stimulated luminescence). They found evidence of tsunamis in 1500 BC, 100-200 CE, 500-600 CE, and 1100-1200 CE. There is still much we still have to learn about tsunamis, especially as more and more areas seem vulnerable to their threat. However, this exact need may be what gives researchers the push they need to find out methods of protection.

Giant Wave Experiment Reveals Poorly Understood Behavior Of Tsunamis

tsunami
People, as a society, find it hard to learn from their mistakes. Since the tragic events caused by tsunamis we have not been able to shelter ourselves from them. But this doesn’t mean researchers are just hanging around – on the contrary. Many scientists are working and they are trying to understand the exact mechanism of how a tsunami is formed; this could mean saving lives and preventing environmental and structural damage.

They do this by making mini-tsunamis in Oregon. A tsunami is a series of waves created when a body of water, such as an ocean, is rapidly displaced. Earthquakes, mass movements above or below water, volcanic eruptions and other underwater explosions, landslides, large meteorite impacts and testing with nuclear weapons at sea all have the potential to generate a tsunami. The effects of a tsunami can range from unnoticeable to devastating.

Their focus is the incoming rush of water and they are ignoring the effect of the powerful forces that a tsunami wave can exert on the earth beneath when it draws back into the ocean.

“This was the first experiment of this kind and it will allow us to develop a realistic model to show us what really happens to the sand during a tsunami,” said Yin Lu “Julie” Young, an assistant professor of civil and environmental engineering at Princeton University’s School of Engineering and Applied Science.

Places like Hawaii lack buildings which are able to resist the force of a tsunami and that brings danger.

“This is absolutely necessary in a place like Waikiki because in the event of a tsunami there is no place to run,” she said. “It is too populated and the near-shore bathymetry is too flat. The building has to stay intact so that people can evacuate vertically.”.

Their interest is enhanced sediment transport and potential “liquefaction” of the soil, which occurs when a tsunami wave recedes.

They are trying to establish “performance-based tsunami engineering”. This means that they are searching for guidelines for building structures which are able to resist tsunamis. The problem is that there are a lot of variables in the dynamics of sand and water, according to Young. “Sediment transport during tsunamis hasn’t been studied well at all,” said Young. “We plan to use this research to create a benchmark test that everyone can use to compare their numerical predictions. Ultimately we want to come up with a design procedure that can give a sense of the risk and the reliability of a structure and its foundation.”. This should be a big step in shielding from this and reducing the damage from tsunami.