Sunday, February 28, 2010

First waves hit Japan and New Zealand after massive Chile earthquake. Now they wait for the big one

By Martin Delgado

Tsunami strikes: Large waves pound concrete breakwaters at a port in Ichinomiya city, Chiba province


Tsunami waves of up to 5 ft hit far-flung Pacific regions from the Russian far east and Japan to New Zealand's remote Chatham Islands today after a massive earthquake struck Chile, killing more than 300 people.

Hundreds of thousands of residents in Japan, New Zealand, the Philippines and Russia's Kamchatka were told to evacuate after Saturday's Chile quake, one of the world's most powerful in a century, but there were no immediate reports of damage.

In Japan, a 5ft tsunami hit the fishing port of Otsuchi on the north Pacific coast, Kyodo news agency said.


More than 150,000 households in Japanese coastal areas were urged to evacuate due to tsunami warnings after a powerful 8.8-magnitude earthquake struck the coast of Chile


Tsunami alert: Streets flooded with seawater in Kesennuma, northern Japan


Smaller waves hit a swathe of the country from the small island of Minamitori 1,200 miles south of Tokyo to Hokkaido island in the north, the Japan Meteorological Agency said.

Japanese officials have ordered or advised some 540,000 households along the country's Pacific coast to evacuate and said later waves could be much bigger.

'The full-fledged tsunami waves are starting to arrive,' University of Tokyo professor Yoshinobu Tsuji told NHK public TV.

'This is not the last one,' he said.

It was Japan's first major tsunami warning in 17 years and only the fourth since 1952, the Japan Meteorological Agency said.

'Carelessness could be the biggest enemy. In the past, even if the waves were not so big, there has been great damage with 2-metre high tsunami,' Prime Minister Yukio Hatoyama told reporters.

Train services were halted in many areas along the Pacific coast and some highways were closed.




This combo photo shows the different levels of water covering a harbour wharf in the Japanese town of Minami-sanriku, Miyagi Prefecture


Smoke from a burning building fills the sky in the outskirts of Santiago after a huge 8.8-magnitude earthquake rocked Chile


Motorists pass under a footbridge that has collapsed over the Panamerican Highway after a major earthquake in Curico


Police work during the rescue operations at a damaged building in Concepcion


Police cars and fire trucks patrolled coastal roads and fishing boats, seeking to avoid any tsunami, headed out to sea under gray skies, with snow flurries in some areas.

The area that could be hit hardest, where around 140 people died in a previous tsunami 50 years ago, has many small harbours that could concentrate the force of a tsunami.

'The waves could climb up the land, so for real safety you should evacuate to a place several times higher than the predicted height of the waves,' JMA official Yasuo Sekita told a news conference.

The agency said the first wave might not be the biggest and that the warning could remain in effect for a long time.

TV footage showed elderly women with cloth-wrapped bundles on their backs gathering at evacuation centres as cars pulled up and other women unloaded shopping bags filled with belongings.

The tsunami warning covered the eastern seaboard of Japan, although for Tokyo Bay and many other areas the warnings were for waves of only around one metre (3 ft).

The area is no stranger to tsunamis.


A huge magnitude-8.8 earthquake struck Chile early on Saturday, knocking down homes and hospitals


Seawater makes its way towards the city center at a port in Kesennuma, northern Japan


In 1896, a magnitude 8.5 earthquake and tsunami left more than 22,000 dead in northeastern Japan. Another of magnitude 8.1 hit the same region in 1933, killing 3,064.

In May 1960, a tsunami struck the coasts of Hokkaido and other northern Pacific coastal areas after an earthquake in Chile, killing around 140 people.

Since then, many harbours have had sea gates installed to try to protect from tsunami and storms.

'Coastal barriers have been built since the 1960 tsunami so we can't simply compare the situation with that time but it is still crucial that people evacuate,' said Masaaki Kubo of the Kamaishi Eastern Fishery Union in Iwate, in northern Honshu.

The first waves to hit New Zealand were reported at the remote Chatham Islands, around 800 kilometres (500 miles) east of New Zealand, with surges of up to 1.5 metres measured, the Civil Defence Ministry said.


How the tsunami swept across the Pacific Ocean


A policeman looks at cars washed up by a wave generated by an earthquake in Talcahuano Port


Fishing boats washed up by a wave generated by an earthquake are seen in Talcahuano Port, a city just outside Concepcion


A resident on one of the smaller islands in the group, Pitt, said the surges were continuing and getting bigger.

'The bay empties right out. It takes about a minute and a half and then it surges back in, in about the same amount of time,' Bernadette Malinson told Radio New Zealand. 'The surges have been getting bigger -- at least 2 metres at present.'

Authorities in Russia's far eastern Kamchatka region lifted a tsunami alert after a series of small waves appeared to cause no damage, a spokeswoman for the Emergencies Ministry said.

A tsunami hit beaches in eastern Australian but there were not initial reports of damage.

Australia issued a tsunami alert for most of its east coast and eastern parts of the island state of Tasmania, but authorities said there were no concerns about major innundation.

Hawaii dodged serious damage on Saturday when a tsunami merely lapped ashore, although residents were warned to stay away from coastal areas because the ocean could remain unsettled for several more hours.

Analysis: Dangers of Ring of FireBy Erin Kelly Beutel
Geology Professor, Charleston College
In its magnitude, yesterday’s earthquake was massive, one of the largest since the 9.1 quake that caused the tsunami in Sumatra in 2004. It was classified as ‘great’, with the potential to cause ‘tremendous damage’ by the U.S. Geological Survey and triggered tsunami warnings as far away as Hawaii.

But it was not a significant surprise to scientists because Chile is located on the Pacific Ring of Fire, a 24,800-mile stretch of nearly continuous oceanic trenches and volcanoes where, historically, about 80 per cent of the world’s largest earthquakes have occurred.

In 1960 Chile was hit by a 9.9-magnitude quake, the biggest since records have been kept. It killed 1,655 people and created a destructive tsunami which battered Easter Island and travelled to Japan and Hawaii, where there were hundreds of other casualties.


Tsunami alert: This image obtained from the National Oceanic and Atmospheric Administration shows a model of the forecast of the tsunami triggered by the earthquake in Chile


The epicentre of the latest earthquake was in a seismic gap 75 miles off the coast where two plates of the Earth’s crust – the South American and Nazca plates – press against each other under the ocean in the ‘subduction zone’.

The Nazca plate has been moving east at three inches per year and sliding under the South American plate. In places the two plates adhered to each other and stress gradually built up until one area where they were stuck cracked, which is what triggered the latest earthquake.

The quake that devastated Port-au-Prince was caused by a different type of plate boundary. Haiti sits on a fault line between two huge tectonic plates, like Chile, but instead of diving under each other, the great slabs of crust slide past one another. Strain built up along faults at the plate boundaries until its release in the earthquake.

There is a saying: ‘Earthquakes don’t kill people. Buildings collapse because of earthquakes and that kills people.’ That was the case in Haiti. That quake measured seven and there were huge casualties because most of their buildings were not designed to withstand shock.


Residents sleep in the streets for fear of aftershocks following a major earthquake in Santiago


Jake Fender and Jason Heun sit atop their van on Round Top Drive on February 27, 2010 in Honolulu, Hawaii. Residents stocked up on food and emergency supplies in preparation for a potentially damaging tsunami


Any large earthquake also generates aftershocks and that is one concern in Chile – but the greater concern is that it occurred under the ocean and caused a tsunami travelling away from the epicentre which could reach as many as 53 countries that border on the Pacific.

Tsunami waves in the deep ocean travel at about the same speed as a jet and experts estimated this one was travelling at hundreds of miles per hour.

Scientists believe it is total coincidence that there have been several major earthquakes in the past few weeks. But there is a debate about whether an earthquake on the kind of scale we have seen in Chile may eventually – way down the years – influence other fault lines and perhaps trigger an earthquake somewhat earlier than would have been expected or cause an active volcano to go dormant or a dormant volcano to start up.

What we know is that large earthquakes send out waves not detectable by people but picked up thousands of miles away on seismometers. If there is any link between one earthquake and another, it is likely to be very minor. But the lesson is that people in earthquake zones always need to be educated and prepared.


source: dailymail

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