GeoGarage blog

Saturday, April 22, 2017

Diving down to the deep ocean

Even in the perpetual darkness of the deepest ocean, scientists discover the discarded rubbish of modern life.

Friday, April 21, 2017

The pristine Arctic has become a garbage trap for 300 billion pieces of plastic

Here’s a map the researchers provided, showing the ocean circulation in the Atlantic and where that, in turn, has delivered plastic particles:
Locations and plastic concentrations of the sites sampled.

The white area shows the extension of the polar ice cap in August 2013, and green curves represent the North Atlantic Subtropical Ocean Gyres and the Global Thermohaline Circulation poleward branch.

(Andres Cozar)

From The Washington Post by Chris Mooney

Drifts of floating plastic that humans have dumped into the world’s oceans are flowing into the pristine waters of the Arctic as a result of a powerful system of currents that deposits waste in the icy seas east of Greenland and north of Scandinavia.
In 2013, as part of a seven-month circumnavigation of the Arctic Ocean, scientists aboard the research vessel Tara documented a profusion of tiny pieces of plastic in the Greenland and Barents seas, where the final limb of the Gulf Stream system delivers Atlantic waters northward.
The researchers dub this region the “dead end for floating plastics” after their long surf of the world’s oceans.
The researchers say this is just the beginning of the plastic migration to Arctic waters.
“It’s only been about 60 years since we started using plastic industrially, and the usage and the production has been increasing ever since,” said Carlos Duarte, one of the study’s co-authors and director of the Red Sea Research Center at the King Abdullah University of Science and Technology in Saudi Arabia.
“So, most of the plastic that we have disposed in the ocean is still now in transit to the Arctic.”

A seal lies on an iceberg in front of the research vessel Tara.

The nonprofit organization Tara Expeditions has been active since 2003, sailing across the world's oceans to study biodiversity, the impacts of climate change and other research topics. In 2013, the schooner sailed around the Arctic Ocean to collect plastic debris floating in the water.
photo : Anna Deniaud / Tara Expeditions Foundation

The results were published Wednesday in the journal Science Advances.
The study was led by Andrés Cózar of the University of Cádiz in Spain along with 11 other researchers from universities in eight nations: Denmark, France, Japan, the Netherlands, Saudi Arabia, Spain, the United Kingdom and the United States.
The researchers estimated that about 300 billion pieces of tiny plastic are suspended in these Arctic waters right now, although they said the amount could be higher.
And they think there is even more plastic on the seafloor.

Tara Oceans expedition route

Several factors support the idea that the plastic entered these waters via ocean currents rather than local pollution.
First, the Arctic has a very small population that is unlikely to directly contribute so much waste. Also, the aged and weathered state of the plastic, and the tiny size of the pieces found, suggested that it had traveled the seas for decades, breaking down along the way.
“The plastic pieces that may have been initially inches or feet in size, they have been brittled by exposure to the sun and then fragmented into increasingly smaller particles, and eventually led to this millimeter-size plastic that we call microplastic,” Duarte said.
“That process takes years to decades. So the type of material that we’re seeing there has indications that it has entered the ocean decades ago.”

Manta net used to collect microplastics

© Anna Deniaud / Tara Expeditions Foundation

Finally, the study didn’t find much plastic in the rest of the Arctic ocean beyond the Greenland and Barents seas, also suggesting that currents were to blame.
Instead the plastic had accumulated where the northward-flowing Atlantic waters plunge into the Arctic depths. Presumably, the plastic then lingers at the surface.
The Greenland and Barents seas contained 95 percent of the Arctic’s plastic, the research found (the ship sampled 42 sites across the Arctic Ocean).
The Barents Sea happens to be a major fishery for cod, haddock, herring and other species.
A key question will be how the plastic is affecting these animals.
Here’s a collage that the researchers provided showing the types of plastic they found:

Photo collage of plastic fragments found in the Arctic Ocean.

Although plastic debris was scarce in most of the Arctic waters, it reached high concentrations in areas of the Greenland and Barents seas. (Credit: Andres Cozar)

The study’s results sent a troubling message to one researcher who has also focused on the consequences of plastic debris in the oceans and other waterways.
“Isn’t it kind of ironic that days before Earth Day there is more demonstrated proof of widespread contamination of our plastic waste in places that are so far from the human footprint and thus locations we consider to be pristine,” said Chelsea Rochman, a marine ecologist at the University of Toronto who was not involved in the study but praised it as “a great contribution to the field.”
The ocean circulation system in the Atlantic responsible for this plastic transport is part of a far larger “thermohaline” ocean system driven by the temperature and salt content of oceans.
It is also often called an “overturning” circulation because cold, salty waters sink in the North Atlantic and travel back southward at deep ocean depths.

Tara expedition

As humans now put 8 million tons of plastic in the ocean annually, learning how such currents affect the plastic’s global distribution is a key scientific focus.
Researchers, including Duarte, previously found that plastic slowly travels the world’s oceans but tends to linger in five “gyres,” or circular ocean currents in the subtropical oceans in both the northern and southern hemispheres.
One of those gyres is located in the Atlantic, which then feeds the Arctic.

Aurora, a three-year-old polar bear, was found with her sister in the Arctic Ocean in May 2010 and brought to the Royev Ruchey Zoo in Siberia.

photo : Ilya Naymushin / Reuters

Scientists noted that the vast majority of ocean plastic becomes lost before it reaches the Arctic.
They aren’t sure where most of the plastic falls out and are researching to determine those locations.
“The plastic that escapes those traps is the one that actually makes it into the Arctic,” Duarte said.
“But when it enters the Arctic, there is no way out, it just stays there and is stuck there.”
Because it takes such a long time for plastic to travel across the world in ocean currents, the study concludes that the current waste is largely the work of North Americans and Europeans, who dumped it in the Atlantic.
Waste from other parts of the world that dump huge volumes of plastic into the oceans is still in transit.
Rochman said she feared that as the Arctic becomes more accessible because of ice melt linked to climate change, more plastic could wash in.
“As the ice melts, we may see increasing concentrations of plastic in the Arctic due to the opening of passageways for vessels and plastics in surface currents,” she said, “as well as plastics in the ice becoming free to float and interact with marine animals upon melting.”

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Thursday, April 20, 2017

Canada CHS update in the GeoGarage platform

84 nautical raster charts updated

see GeoGarage news

A banned Indian island: Watch video of Sentinelese tribe rejecting attempts at communication

After numerous failed attempts to make contacts with the Sentinelese tribe since 1964, the Indian government has finally backed away.

From Indian Express

Surprisingly there has been only one instance when outsiders didn't have to face a hostile reception.

A rare footage of the Sentinelese, one of the last uncontacted tribes in the world, has emerged, showing its members on the beaches of North Sentinel Island in Andaman & Nicobar.

North Sentinel Island with the GeoGarage platform (NGA chart)

Thought to be direct descendants of the first humans who emerged from Africa, the tribe is believed to be living on the tiny Indian island for almost 60,000 years.
Little is known about their exact population and could reportedly have as low as 40 members or as high as 500.

North Sentinel island, NASA

Efforts to reach out to them have been met with hostility and there are several horror stories of how Sentinelese have treated their guests.
People return from the island either injured or not at all. In 2006 two fishermen, aged 48 and 52, were killed after they slept overnight in their boat near the North Sentinel island.

Following the 2004 tsunami, helicopters from the Indian Coast Guard were sent to drop food parcels, but this tribesmen responded by firing an arrow at the rescue team

They were hostile even during emergency rescue missions after Tsunami in 2004 as gifts, food and clothing are of no importance to them.
A photo was captured of one of the tribesmen taking aim at a rescue helicopter with an arrow.

According to a video footage which is a part of a documentary by LoveBite Productions on the Sentinelese tribe, an Indian anthroplogist T N Pandit who conducted several government trips to the island in the late 80’s and the early 90’s in an attempt to reach out confessed, “Sometimes they would turn their backs and sit on their haunches as to defecate. This was meant to insult us as we were not welcomed. It doesn’t matter if you are a friend or an enemy or you arrive at the island’s shores by purpose or by accident, the locals would greet you the same way with spears and arrows.”

Surprisingly there has been only one instance when outsiders didn’t have to face a hostile reception.
On January 4, 1991, 28 people which included men, women and children approached Pandit and his team saying the tribe voluntarily came forward to meet them.
However, after numerous failed attempts to make contacts with them since 1964, the Indian government has finally backed away.
In 2005, the administration of Andaman & Nicobar stated that they have no intention of interfering with the lifestyle of the Sentinelese tribe or pursuing any further contact with them.
Also, the Indian navy enforced a 3 mile buffer zone to keep tourists and explorers away.

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Wednesday, April 19, 2017

Climate change to deliver regular flooding to Europe

The 1824 flooding for St. Petersburg, Russia.

Once-a-century floods could become commonplace as the planet heats up.

From NexusMedia by Marlene Cimons

Sea-level rise threatens coastal communities.

The kind of devastating flooding that occurs once every century along Europe’s northern coastline could become an annual event if greenhouse gas emissions continue to climb, according to a recent study published in the journal Earth’s Future.

New analysis takes into account changes in sea-level rise, tides, waves and storm surge over the 21st century and found that climate change could prompt extreme sea levels — the maximum levels seen during major storms, which produce massive flooding — to increase significantly along the European coastline by 2100.

This scenario will likely stress coastal protection structures beyond their capacity, leaving much of the European coastline vulnerable to dangerous flooding, according to study authors.

“Unless we take different protection measures, five million people will be exposed to coastal flooding on an annual basis,” said Michalis Vousdoukas, a coastal oceanographer at the Joint Research Centre of the European Commission and lead author of the study.

The study described the projected rise in extreme sea levels as “a serious threat” to coastal communities, noting, “their safety and resilience depends on the effectiveness of natural and man-made coastal flood protection.”

Kevin Trenberth, a scientist with the climate analysis section of the National Center for Atmospheric Research, who was not involved in this research, said the signs of extreme sea levels are already worrisome, not just in Europe, but in the United States as well.

“Witness the sunshine flooding in Florida already, the flooding that shows up even with no storm on many streets any time there is a slightly high tide,” he said.

A Florida road flooded by tropical storm Arlene in 2005.

Florida is especially susceptible to rising seas.

Source: FEMA

“Sea level is going up because the ocean is warming and hence expanding, and because land ice — glaciers, etc. — are melting and putting more water into the ocean. But it is not the gradual rise that matters,” Trenberth said. “Rather, it is the storm surge on top of a high tide riding on top of the increase in sea level that crosses thresholds and causes things to break.”

Richard Alley, professor of geosciences at Pennsylvania State University, who also did not take part in this study, noted that the study didn’t consider the possible collapse of the West Antarctic ice sheet. “If that happens, then sea-level rise and impacts to coasts could be much higher than in this paper,” Alley said. “Rapid West Antarctic collapse could cause enough rise to make many of these other factors of secondary importance. So, the ‘worst case’ in this paper isn’t really the worst case.”

The new paper predicted that some regions could experience an even higher increase in the frequency of these extreme flooding events, specifically along the Mediterranean and the Black Sea, where the present day 100-year extreme sea level could occur as often as several times a year.

Information about the number of people at risk from flooding can be used to determine how large the social and economic impact of these events will be, said Marta Marcos, a researcher at the Mediterranean Institute for Advanced Studies in Spain, who was not involved in the new study. “In terms of adaptation strategies and policy-making, it is very relevant,” she said.

The researchers studied changes in extreme sea levels by 2100 under different greenhouse gas scenarios and considered how all these components — mean sea level, tides, waves and storm surge — will be affected by climate change.

The Netherlands is particularly vulnerable to sea-level rise.

Source: Pexels

If emissions continue to rise unabated throughout this century, extreme sea levels along Europe’s coastlines could increase by more than 2.5 feet, on average, by 2100.

Under a more moderate situation, where greenhouse gas emissions peak in 2040, 100-year extreme sea levels still could jump by nearly 2 feet, on average, by the end of the century — with flooding events occurring every few years — according to study’s authors.

In a related study appearing in Geophysical Research Letters, scientists found that if greenhouse gases continue to rise, there could be disturbing changes by the end of the century in the energy that waves carry to the coast.

In the southern hemisphere, extreme waves could carry up to 30 percent more energy by 2100, according to the study, meaning that stronger waves will become more frequent, and have a greater impact on the coast, said Lorenzo Mentaschi, a researcher at the Joint Research Centre and lead author of the study.

The new study attributed the changes in wave energy to the intensification of weather patterns, like El Niño.

The new research will be provided to European Union policymakers.

The data will also be made public so it can be used by scientists, engineers and coastal managers.

Michael Mann, professor of atmospheric science at Pennsylvania State University, said the research once again underscored how climate change, “which has already increased the threat to our coastlines through a combination of sea-level rise and intensified coastal storms, will be catastrophic for coastal communities if we don’t reduce global carbon emissions.”

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