Deepest scientific ocean drilling sheds light on Japan’s next great earthquake

Peer-Reviewed Publication

UNIVERSITY OF TEXAS AT AUSTIN

 

IMAGE: THE DEEP SEA SCIENTIFIC DRILLING VESSEL CHIKYU, WHICH IN 2018 PERFORMED THE DEEPEST DRILLING OF A SUBDUCTION ZONE EARTHQUAKE FAULT. view more 

CREDIT: SATOSHI KAYA/FLICKR

Scientists who drilled deeper into an undersea earthquake fault than ever before have found that the tectonic stress in Japan’s Nankai subduction zone is less than expected, according to a study from researchers at The University of Texas at Austin and University of Washington.

The findings, published in the journal Geology, are a puzzle because the fault produces a great earthquake almost every century and was thought to be building for another big one. 

“This is the heart of the subduction zone, right above where the fault is locked, where the expectation was that the system should be storing energy between earthquakes,” said Demian Saffer, director of the University of Texas Institute for Geophysics (UTIG) who co-led the research and scientific mission that drilled the fault. “It changes the way we’re thinking about stress in these systems.”

Although the Nankai fault has been stuck for decades, the study shows that it is not yet showing major signs of pent-up tectonic stress. According to Saffer, that doesn’t alter the long-term outlook for the fault, which last ruptured in 1946 – when it caused a tsunami that killed thousands – and is expected to do so again during the next 50 years. 

Instead, the findings will help scientists home in on the link between tectonic forces and the earthquake cycle and potentially lead to better earthquake forecasts, both at Nankai and other megathrust faults such as Cascadia in the Pacific Northwest.

“Right now, we have no way of knowing if the big one for Cascadia – a magnitude 9 scale earthquake and tsunami – will happen this afternoon or 200 years from now,” said Harold Tobin, a researcher at the University of Washington who is the first author of the paper. “But I have some optimism that with more and more direct observations like this, we can start to recognize when something anomalous is occurring and that the risk of an earthquake is heightened in a way that could help people prepare.” 

Megathrust faults such as Nankai, and the tsunamis they generate, are among the most powerful and damaging on the globe, but scientists say they currently have no reliable way of knowing when and where the next big one will hit.

The hope is that by directly measuring the force felt between tectonic plates pushing on each other – tectonic stress – scientists can learn when a great earthquake is ready to happen. 

However, the nature of tectonics means that the great earthquake faults are found in deep ocean, miles under the seafloor, making them incredibly challenging to measure directly. Saffer and Tobin’s drilling expedition is the closest scientists have come.

Their record-breaking attempt took place in 2018 aboard a Japanese scientific drilling ship, the Chikyu, which drilled 2 miles into the tectonic plate before the borehole got too unstable to continue, a mile short of the fault. 

Nevertheless, the researchers gathered invaluable data about subsurface conditions near the fault, including stress. To do that, they measured how much the borehole changed shape as the Earth squeezed it from the sides, then pumped water to see what it took to force its walls back out. That told them the direction and strength of horizontal stress felt by the plate pushing on the fault.

Contrary to predictions, the horizontal stress expected to have built since the most recent great earthquake was close to zero, as if it had already released its pent-up energy.

The researchers suggested several explanations: It could be that the fault simply needs less pent-up energy than thought to slip in a big earthquake, or that the stresses are lurking nearer to the fault than the drilling reached. Or it could be that the tectonic push will come suddenly in the coming years. Either way, the researchers said the drilling showed the need for further investigation and long-term monitoring of the fault.

The research was funded by the Integrated Ocean Drilling Program and the Japan Agency for Marine-Earth Science and Technology. UTIG is a research unit of UT Austin’s Jackson School of Geosciences.

Harold Tobin of the University Washington inspects drilling risers. Researchers used similar equipment during a record-breaking attempt to drill Japan’s Nankai fault in 2018 that was co-led by the University of Texas Institute for Geophysics.

CREDIT

Harold Tobin/University of Washington

A drilling riser aboard the scientific drilling vessel Chikyu. Dozens of risers were linked together to reach deeper into an earthquake fault than ever before. Led by researchers at the University of Texas Institute for Geophysics and University of Washington, the scientific mission revealed that tectonic stress in Japan’s Nankai subduction zone was lower than expected.

CREDIT

Demian Saffer/University of Texas Institute for Geophysics

CAPTION

Demian Saffer, director of the University of Texas Institute for Geophysics (UTIG), during scientific ocean drilling at Japan’s Nankai earthquake fault.

CREDIT

Demian Saffer/University of Texas Institute for Geophysics

JOURNAL

Geology

DOI

10.1130/G49639.1 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Direct constraints on in situ stress state from deep drilling into the Nankai subduction zone, Japan

Tonga volcano blast was unusual, could even warm the Earth

By MADDIE BURAKOFF

September 22, 2022

In this photo provided by New Zealand's Ministry of Foreign Affairs and Trade, the Hunga Tonga-Hunga Ha’apai volcano erupts near Tonga in the South Pacific Ocean on Jan. 14, 2015. The volcano shot millions of tons of water vapor high up into the atmosphere according to a study published Thursday, Sept. 22, 2022, in the journal Science. Researchers estimate the event raised the amount of water in the stratosphere - the second layer of the atmosphere, above the range where humans live and breathe - by around 5%. 

(AP Photo/New Zealand's Ministry of Foreign Affairs and Trade)


NEW YORK (AP) — When an undersea volcano erupted in Tonga in January, its watery blast was huge and unusual — and scientists are still trying to understand its impacts.

The volcano, known as Hunga Tonga-Hunga Ha’apai, shot millions of tons of water vapor high up into the atmosphere, according to a study published Thursday in the journal Science.

The researchers estimate the eruption raised the amount of water in the stratosphere — the second layer of the atmosphere, above the range where humans live and breathe — by around 5%.

Now, scientists are trying to figure out how all that water could affect the atmosphere, and whether it might warm Earth’s surface over the next few years.

“This was a once-in-a-lifetime event,” said lead author Holger Voemel, a scientist at the National Center for Atmospheric Research in Colorado.

Big eruptions usually cool the planet. Most volcanoes send up large amounts of sulfur, which blocks the sun’s rays, explained Matthew Toohey, a climate researcher at the University of Saskatchewan who was not involved in the study.

The Tongan blast was much soggier: The eruption started under the ocean, so it shot up a plume with much more water than usual. And since water vapor acts as a heat-trapping greenhouse gas, the eruption will probably raise temperatures instead of lowering them, Toohey said.

It’s unclear just how much warming could be in store.

Karen Rosenlof, a climate scientist at the National Oceanic and Atmospheric Administration who was not involved with the study, said she expects the effects to be minimal and temporary.

“This amount of increase might warm the surface a small amount for a short amount of time,” Rosenlof said in an email.

The water vapor will stick around the upper atmosphere for a few years before making its way into the lower atmosphere, Toohey said. In the meantime, the extra water might also speed up ozone loss in the atmosphere, Rosenlof added.

But it’s hard for scientists to say for sure, because they’ve never seen an eruption like this one.

The stratosphere stretches from around 7.5 miles to 31 miles (12 km to 50 km) above Earth and is usually very dry, Voemel explained.

Voemel’s team estimated the volcano’s plume using a network of instruments suspended from weather balloons. Usually, these tools can’t even measure water levels in the stratosphere because the amounts are so low, Voemel said.

Another research group monitored the blast using an instrument on a NASA satellite. In their study, published earlier this summer, they estimated the eruption to be even bigger, adding around 150 million metric tons of water vapor to the stratosphere — three times as much as Voemel’s study found.

Voemel acknowledged that the satellite imaging might have observed parts of the plume that the balloon instruments couldn’t catch, making its estimate higher.

Either way, he said, the Tongan blast was unlike anything seen in recent history, and studying its aftermath may hold new insights into our atmosphere.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Hurricane Fiona: Canada hit by 'historic, extreme event'

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Watch: Storm Fiona hits Canada's Atlantic coastline

Hundreds of thousands of people have been left without power, after Storm Fiona hit Canada's coastline.

Fiona was downgraded from a hurricane to a tropical storm on Friday.

But parts of Nova Scotia, Prince Edward Island and New Brunswick still experienced torrential rain and winds of up to 160km/h (99mph), with trees and powerlines knocked down.

Prime Minister Justin Trudeau said the situation was critical, and promised to provide support through the army.

Officials have yet to share reports of fatalities or serious injuries, but authorities are dealing with extensive flooding.

In a briefing Mr Trudeau described Fiona as "a very powerful and dangerous storm" and said the army will be deployed to help with assessment and clean-up efforts. His government has already responded positively to a request by Nova Scotia authorities for assistance.

"If there is anything the federal government can do to help, we will be there," he said, adding that he would no longer travel to Japan to attend the funeral of former Prime Minister Shinzo Abe.

Tropical storm warnings were issued for the Atlantic provinces of Nova Scotia, Prince Edward Island, Newfoundland and New Brunswick, as well as in parts of Quebec.

The country's eastern region could receive up to 10in (25cm) of rain, increasing the risk of flash flooding.

IMAGE SOURCE,REUTERS

Image caption,

A man attempts to protect the Nova Scotia power building in Halifax, Nova Scotia

In Nova Scotia, shelters were prepared in Halifax and Cape Breton for people to take cover ahead of the storm.

"We have been through these types of events before, but my fear is, not to this extent," said Amanda McDougall, mayor of Cape Breton Regional Municipality. "The impacts are going to be large, real and immediate."

In Port aux Basques, with a population of 4,067 on the southwest tip of Newfoundland, intense flooding saw some homes and office buildings washed out to sea, local journalist Rene Roy, told CBC. The area is under a state of emergency.

"This is hands down the most terrifying thing I've ever seen in my life," Mr Roy said.

He added that many homes were left as "a pile of rubble in the ocean right now", adding: "There is an apartment building that's literally gone. There are entire streets that are gone."

Officials later confirmed that at least 20 homes had been lost.

And the Royal Canadian Mounted Police said a woman was rescued after being "tossed into the water as her home collapsed" in the area. They said another report of a women being swept out from her basement had been received, but conditions remained too dangerous to conduct a search.

Power companies have warned that it could take days to restore electricity, as wind speeds remain too high to start work on downed power lines.

Severe hurricanes in Canada are rare, as storms lose their energy once they hit colder waters in the north and become post-tropical instead. But pressure in the region is predicted to be historically low as Storm Fiona hits, making way for a heavier storm.

Nova Scotia was last battered by a tropical cyclone in 2003 with Hurricane Juan, a category two storm that killed two people and heavily damaged structures and vegetation.

Meteorologist Bob Robichaud warned on Friday afternoon that Fiona will be bigger than Juan, and stronger than 2019's Hurricane Dorian, which also reached the shores of Nova Scotia.

Fiona had already wreaked havoc on Puerto Rico and the Dominican Republic earlier this week, with many still left without power or running water.

Florida also faces a hurricane threat as tropical storm Ian strengthened as it moved over the Caribbean on Saturday. It could approach Florida early next week as a major hurricane.

Ian's projected path takes it just south of Jamaica, over western Cuba and into Florida, the hurricane centre said.

Florida Keys and South Florida could be hit by heavy rains on Monday, according to forecasters.

Florida Governor Ron DeSantis declared a state of emergency on Friday, freeing up funding and emergency services in advance of the storm.

Storm Fiona hits eastern Canada, leaving 'total devastation'

Powerful storm Fiona lashed into eastern Canada on Saturday, cutting power to thousands and washing houses into the sea as it pummeled the area with fierce winds and rains "like nothing we've ever seen," police said.


Storm Fiona hits eastern Canada, leaving 'total devastation'

© Vaughan Merchant, The Canadian Press, AP

Two women were swept into the ocean in Newfoundland, the Royal Canadian Mounted Police reported. One was rescued, but the other is still missing.

Mayor Brian Button of Channel-Port aux Basques, at the southwestern tip of Newfoundland, told CBC News that the scene there was one of "total devastation," adding, "this has become bigger, and worse, than we had imagined."

Rene Roy, a newspaper editor in Channel-Port aux Basques, said, "These are the strongest winds anyone in the community has ever seen. Several houses have been washed into the sea."

As of midday, some 500,000 homes were left without power across the region as the storm pummeled a wide area, felling countless trees and ripping roofs from buildings.

"The power lines are down everywhere," Erica Fleck, assistant chief of Halifax Regional Fire and Emergency, told CBC. "It's not safe to be on the roads."

Although downgraded to a post-tropical cyclone, Fiona still packed hurricane-force winds of 80 miles (130 kilometers) per hour as it barreled into Canada after earlier battering the Caribbean, according to meteorologists.

Nova Scotia hard hit

The storm first made landfall in Nova Scotia province around 3:00 am (0600 GMT), according to the Canadian Hurricane Center (CHC).

In Nova Scotia, 384,000 households were without electricity by midday Saturday, Nova Scotia Power reported, while New Brunswick reported 32,000 and Prince Edward Island some 82,000.


"Trees have come down on homes, trees have come down on cars, there's buildings that have collapsed," Fire Chief Lloyd MacIntosh in the Nova Scotia town of North Sydney told CBC.

Police in Charlottetown, the capital of Prince Edward Island, posted images of tangles of downed power lines and roofs punctured by felled trees.

"It's incredible," said Charlottetown mayor Philip Brown on Radio-Canada TV. "It's stronger than Hurricane Juan in 2003."

Nova Scotia Premier Tim Houston said in a statement that "it will take time for Nova Scotia to recover. I just ask everyone for their patience."

Canadian Prime Minister Justin Trudeau tweeted: "I want you to know that we're here for you... Our government stands ready to support the provinces with additional resources."

Canada had issued severe weather warnings for swaths of its eastern coast, advising people to lay in supplies for at least 72 hours.

Rainfall of up to 4.9 inches (125 millimeters) was recorded in Nova Scotia and Prince Edward Island, the CHC said, with waves of up to 40 feet (12 meters) hitting Nova Scotia and western Newfoundland.

The CHC said conditions would improve in western Nova Scotia and eastern New Brunswick later Saturday and over southwestern Newfoundland and Iles-de-la-Madeleine late Saturday night.

Puerto Rico struggling

Fiona had skirted Bermuda a day earlier, with residents battening down and authorities calling for people to remain inside as strong winds raked over the British territory. No fatalities or major damage were reported as the storm passed roughly 100 miles to the west of the island.

Bermuda, whose economy is fueled by international finance and tourism, is wealthy compared with most Caribbean countries, and structures must be built to strict planning codes to withstand storms. Some have done so for centuries.

Fiona killed at least four people in Puerto Rico earlier this week, according to US media, while two deaths were reported in the Dominican Republic and one in the French overseas department of Guadeloupe.

President Joe Biden declared a state of emergency in Puerto Rico, a US territory that is still struggling to recover from Hurricane Maria five years ago.

In the Dominican Republic, President Luis Abinader declared three eastern provinces to be disaster zones.

As the Caribbean licked its wounds from Fiona, Cuba, Jamaica and Florida were bracing Saturday for the arrival of tropical storm Ian, which is expected to gain power in coming days to reach "at or near major hurricane strength," the NHC said.

In anticipation of the storm, NASA called off the scheduled Tuesday launch of its historic uncrewed mission to the Moon.

(AFP)

More on this story

• Hurricane Fiona intensifies

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• Forecasters predict a very active hurricane season

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• Two dead as Hurricane Fiona devastates Puerto Rico

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‘We demand wages for housework’

In the 1970s, an international campaign demanded that governments recognise the value of unpaid work done in the home, primarily by women.

Founded in Italy by Mariarosa Dalla Costa, Selma James, Silvia Federici and Brigitte Galtier, the ‘Wages for Housework’ movement argued that the entire capitalist system was based on free domestic labour.

Witness History spoke to one of the founders, Mariarosa Dalla Costa about the campaign.

Witness History: The stories of our times told by the people who were there.

LA REVUE GAUCHE - Left Comment: Whose Family Values? 

Ukraine war: Hundreds arrested as Russian draft protests continue

By Matt Murphy
BBC News

Published

IMAGE SOURCE,GETTY IMAGES

Hundreds of people have been arrested by authorities as protests against Russia's new "partial mobilisation" continue across the country, an independent rights group has said.

OVD-Info said 724 people were detained across 32 different cities on Saturday.

Widespread demonstrations have broken out since President Vladimir Putin announced plans to draft 300,000 men to fight in Ukraine.

Unsanctioned rallies are banned under Russian law.

But Mr Putin's move to draft civilians into the military has sparked large scale protests in urban areas, with more than 1,000 people being detained at demonstrations earlier this week.

In Moscow, news agency AFP reported witnessing one demonstrator shouting "we are not cannon fodder" as she was arrested by officers.

And in St Petersburg, Russia's second city, one man told reporters: "I don't want to go to war for Putin."

Seventy-year-old Natalya Dubova told AFP that she opposed the war and confessed she was "afraid for young people" being ordered to the front.

Some of those arrested on Saturday reported being handed draft papers and ordered to report to recruiting centres while being held by security officials. The Kremlin defended the practice earlier this week, saying "it isn't against the law".

Moscow has also approved harsh new punishments for those accused of dereliction of duty once drafted.

Mr Putin signed fresh decrees on Saturday imposing punishments of up to 10 years imprisonment for any soldier caught surrendering, attempting to desert the military or refusing to fight.

The president also signed orders granting Russian citizenship to any foreign national who signs up to serve a year in the country's military.

The decree, which some observers have suggested displays how severe Moscow's shortage of troops has become, bypasses the usual requirement of five years of residency in the country.

• Russia reveals exemptions as men flee call-up
• What does Russian military call-up mean for Ukraine?
• Putin fires deputy defence chief amid supply failures

Elsewhere, other young Russians continue to flee mobilisation by seeking to leave the country.

On the border with Georgia, queues of Russian cars stretch back more than 30km (18 miles) and the interior ministry has urged people not to travel.

Local Russian officials have admitted that there's been a significant influx of cars trying to cross - with nearly 2,500 vehicles waiting at one checkpoint.

The admission is a change of tone from Russia, with the Kremlin describing reports of Russians fleeing conscription as "fake" on Thursday.

Meanwhile, Finland has also seen a sharp increase in the number of Russians seeking to enter the country.

Matti Pitkaniitty, a spokesperson for the country's Border Guard, said said the number of Russians arriving had more than doubled since last week.

On Friday, the government announced plans to stop Russian tourists entering the country.

"The aspiration and purpose is to significantly reduce the number of people coming to Finland from Russia," President Sauli Niinistö told the state broadcaster.

Several other neighbouring states have already ruled out offering asylum to Russians seeking to avoid the draft.

"Many Russians who now flee Russia because of mobilisation were fine with killing Ukrainians," Latvia's Foreign Minister Edgars Rinkēvičs said. "They did not protest then. It is not right to consider them as conscientious objectors."

On Friday, the Kremlin revealed a host of occupations it said will be exempt from conscription aimed at boosting its war effort in Ukraine.

IT workers, bankers and journalists working for state media will escape the "partial mobilisation" announced by President Putin on Wednesday.

But some have cast doubt on the truth of the Kremlin's claims, and reports have been emerging of Russian men who do not meet the criteria being called up by local recruiting officers.

Margarita Simonyan, the editor of the state-run media outlet RT, posted to Twitter a list of elderly and disabled citizens ordered to report for duty.