Archives for : December2013

Thin fault zone, slippery clay behind gravity distorting quake

Had a story published in New Scientist about research at the quake subduction zone revealing weak geological factors at the fault zone being behind the massive quake that hit Japan’s northeast in 2011. It sounds as though this is one of those “duh” moments, but methods used to come to this conclusion are truly groundbreaking, involving deep-sea drilling more than

Photo shows the Chikyu (Earth) deep sea research vessel docked at Shimizu port in Shimizu, Shizuoka Prefecture, Japan on 11 Sept. 2013. Photographer: Rob Gilhooly. All rights reserved.

800 meters below the seabed at the subduction site, which itself is over 7 km below the water.

The research was conducted aboard the Chikyu deep-sea research vessel (pictured right), which I recently boarded when it docked a couple of months ago — a fascinating experience in itself and one I shall be writing about.

 

Using the data collected from the site during research that began in early 2012, three papers were published in the peer-reviewed Science journal by a team of international scientists.

The first is about the geology of the fault zone and the main result found there is that the fault zone is only about 5 meters or less thick. “That’s fairly unusual and different from what we have observed in other subduction zones. Usually in the 10s of meters or more,” researcher James Mori told me.

The second paper is about measuring the friction of the fault using the core sample of the fault zone material and putting it in a machine that simulates an earthquake and measures the friction. The main result from that paper is the friction is very low due to a huge presence of called smectite — a a slippery clay that is often found to be at the centre of large landslides in Europe. “That means the fault slips very easily during the big earthquake,” Mori added. “Essentially this is the first time such material has been taken from a big subduction zone earthquake so it’s really a brand new result.”

The third paper relates to temperature measurement taken using devices that were placed in the boreholes earlier this year. This too was designed to measure friction. Essentially the same results were found as from other core sample experiment, meaning researchers had two very different ways of estimating the friction. Both  gave about the same level of what is called the “coefficient of friction”. In this case the COF was about 0.1, which is very low — most rocks slip at a COF of about 0.5 or 0.6.

“So one of the ways of applying this is to say that subduction zones that have especially thin fault zones with a lot of smectite potentially can produce these very large slips of 50 meters and potentially could produce very large tsunamis,” said Mori. “That’s not to say that … if there is no smectite there is not going to be big tsunamis — that’s not a good conclusion.”

A separate report utilised data taken from the European Space Agency’s GOCE satellite that showed the March 2011 quake had been “felt” in space and distorted gravity over time.

6000 demonstrators voice disapproval of Japan state secrets bill

By Rob Gilhooly

Over 6,000 people gathered to form a human chain around Japan’s National Diet in Tokyo Wednesday to protest against the controversial state secrets protection bill that is expected to become law this Friday.

Despite the inevitability of the bill being rubber stamped before the 185th extraordinary session of the Diet comes to a close on Dec. 6, opponents continue to voice their concerns that the bill is being unnecessarily rushed through Parliament.

If passed, the bill could  impose hefty penalties on leaks of any information deemed sensitive, opponents say. It will also inhibit media coverage and be used to conceal official wrongdoings, they add.

If ratified the law would give ministries the freedom to declare as classified just about anything they want, said Upper House member Takashi Esaki.

The longer (the bill’s enactment) can be delayed, the bigger public opinion will grow and can be heard,” he said. “If that were allowed to happen, the bill could be repealed. (Prime Minister Shinzo) Abe knows that, which is why he’s pushing the bill through so quickly.”

This has led some leading figures to question Abe’s true intentions, with a group of academics headed by Nobel Prize winners Toshihide Masakawa and Hideki Shirakawa stating that the issue was the “biggest threat to democracy since World War II.”

During Wednesday’s demonstrations, banners accused Abe of “steamrollering,” while chants from spirited demonstrators referred to the prime minister and ruling Liberal Democratic Party secretary general Shigeru Ishiba as “terrorists” and “facists.”

Ishiba has incited vitriolic criticism since writing in his blog last Friday that citizens who demonstrate against the state secrets bill are committing “an act of terrorism”.

Even though the bill enactment is pretty much a done deal, I decided to come out here today to voice my objection, but also to take a look at what a terrorist looks like,” said Hiroshi Satomi. “What I have seen is ordinary people shouting and singing about something they are wholeheartedly against. The real terrorists are inside that building over there,” he added pointing at parliament across the road.

People like Ishiba are not interested in democracy, said another protestor, Toshiko Miwa. “They call their party the Liberal Democratic Party, but there is nothing liberal or democratic about Ishiba or Abe,” she said. “I have started to see posters and so on showing Abe’s face superimposed over those of Nazis. I think that’s absolutely true.”

Another protestor, Naoki Takahashi expressed fear of a bill that by its nature is given excessive leeway when it comes to transparency. “It seems almost unconstitutional that lawmakers should be able to rush through a secrecy bill that does not clearly define what constitutes sensitive state secrets or even what acts would be deemed punishable” under the bill, he said.

The bill also does not bode well for the media industry, said a Tokyo union organiser and journalist Chie Matsumoto during a separate rally held by around 600 Japan newspapers’ union members. “It could mean information is less easy to obtain and even information that is not even sensitive may not be given out by officials due to a fear that it might land them in trouble,” she said.

Upper House member Esaki said the bill is a flashback to a pre-war, Imperial times and undemocratic laws that gave authorities the right to arrest anyone who voiced disapproval of the government.

We are now a step closer to Abe’s ultimate plan, which is constitutional amendment and in particular an amendment to article 9 (which outlaws war as a means of settling international disputes involving the state),” the Democratic Party of Japan lawmaker said. “He is targeting the right of self defence … this is part of Abe’s life work, something that he started in his first stint as Prime Minister.

He is a politician who wants to return to the way things were before the war — a stronger nation, a nation that worships the emperor, a nation that above civilian rights to know demands a unified, national commitment. In other words, a country that is some distance away from being either liberal or democratic.”

 

 

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