Canada CHS layer update in the GeoGarage platform

72 nautical charts have been updated & 1 new chart added

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NOAA : How can we assist you?

NOAA Office of Coast Survey’s new ASSIST interface.

From NOAA

NOAA makes it easier to submit a comment or report a nautical chart error

On November 16, 2018, NOAA released ASSIST, a new system for submitting questions and reporting nautical chart errors to NOAA’s Office of Coast Survey.
ASSIST has a mobile-friendly design and improved user interface that allows customers to access the system conveniently from any device.
This new tool replaces Coast Survey’s Inquiry and Discrepancy Management System (IDMS), a database that collected nearly 20,000 comments, inquiries, and discrepancy reports since 2008. ASSIST is available from: https://www.nauticalcharts.noaa.gov/customer-service/assist/

ASSIST offers new features including the ability to:

• Tag your submission on a NOAA chart, map, or satellite imagery
• Enter reports from a cell phone or other mobile device
• Comment or report an error using a single form

These improvements streamline the internal Coast Survey workflow, allowing faster, more efficient responses to customers.

Weightless jellies

Jellies have two kinds of skin tissues: an outer exchange layer and an inner "stomach skin".
The frilly parts in the center are called oral arms—projections of the stomach made of gastrodermis that digest food at a distance

Pacific Sea Nettles blissfully at home in the Georgia Aquarium, Atlanta, Georgia.
I was struck by their beauty. Like little spaceships floating in the depths of space.
Graceful, elegant, constantly moving, drifting.
As I filmed, I listened to the crowd as they came and went.
Everyone with children told their child: "Look! They will sting you!"
Not one person in the crowd in the hour that I was there filming commented on the Sea Nettle's beauty. Not one. What does this say about us?

Oh, comb on now! We have two species of comb jelly sharing their exhibit at the moment—the lobed comb jelly Bolinopsis infundibulum and the sea gooseberry Pleurobrachia bachei. That there's a well-coiffed duo!

Links :

• Vimeo : Jellyfish /

What if Greece extends its Territorial Waters to 12 Miles in the Aegean?

From GreekReporter by Tasos Kokkinidis

Former Foreign Minister Nikos Kotzias made a final announcement in October as he handed the ministry’s portfolio to Alexis Tsipras.
He said Greece is ready to extend its territorial waters from 6 to 12 nautical miles.

Aegean dispute

In the first stage, he said, Greece will expand its sovereignty towards the west from the Diapontia Islands, a cluster of small islands in the Ionian Sea, to Antikythera, an island lying between the Peloponnese and Crete.
But the plan is to also do the same in the Aegean.

Kotzias said that the move constitutes the “first extension of the country’s sovereignty since the Dodecanese became part of Greece in 1947.”
Extension in the Ionian is unlikely to cause any objections from its neighbors Italy and Albania.

 Greece-Turkey (National Geographic 1958)

But, the Aegean is a different proposition altogether.
Turkey has threatened in the past that such a move, which it says in effect turns the Aegean into a Greek lake, is a cause of war (casus belli).

Map of the Aegean islands, indicating date of incorporation into Greece.

Law of the Sea

Territorial waters are an extension to the sea of the national sovereignty of a country beyond its shores.
They are considered to be part of the country’s national territory.

They give the littoral state full control over air navigation in the airspace above, and partial control over shipping, although foreign ships (both civil and military) are normally guaranteed innocent passage through territorial waters.

Greece has a legal right to extend its territorial sea to 12 nautical miles, as provided for by the United Nations Convention on the Law of the Sea.

Virtually all coastal states abide by the Law of the Sea, including Turkey, which since 1964 has expanded its territorial waters in the Black Sea and the Mediterranean to 12 nautical miles.

When ratifying the Convention, Greece tabled a statement declaring that “the time and place of exercising these rights … is a matter arising from its national strategy.”

Successive Greek governments refrained from exercising this legal right.
Six nautical miles have been in force since 1936, and since then there has been a continuing debate on whether Greece should extend to 12 nautical miles.

A Turkish coast guard ship patrols in the Aegean Sea off the Turkish coast

Turkey’s threat

If Greece extends its territorial waters in the Aegean, it will increase its control from the current 43 percent to 71 percent.
International waters will be reduced from 49 percent to less than 20 percent. (see maps above)

This is why Turkey has threatened war.
It claims that the Aegean is a special case and if the provisions of the Law of the Sea are applied, Turkey will be cut off from the Sea.

Imia, the two small rocky islands that lie in the Aegean Sea and have been a source of dispute between the two nations in 1996.

At the back, the Small Imia and on the front of the picture Big Imia.

Localization of th tiny barren islets of Imia/Kardak, situated between the Dodecanese island chain and the Turkish mainland

Imia islands with the GeoGarage platform (NGA chart)

 ICAO map, 1955

source : HRI

Greece rejects Turkey’s arguments saying that under the Law of the Sea the right of passage is fully safeguarded and even expanded.
By making use of these rights, even warships from other countries can move undisturbed from Greek territorial waters and through narrow passages between the islands, as is done today.

Tensions over the 12-mile question ran highest between the two countries in the early 1990s, when the Law of the Sea was going to come into force.
On 9 June 1995, the Turkish parliament officially declared that unilateral action by Greece would constitute a casus belli.

This declaration has been condemned by Greece as a violation of the Charter of the United Nations, which forbids “the threat or use of force against the territorial integrity or political independence of any state”.

Links :

• Ekathimeri : Factbox: Greece’s territorial waters and Turkey
• Reuters : Greece, Turkey snipe over maritime borders
• RhulGeopolitics : Casus Belli: A Turkish Policy for the Aegean Sea
• AhvalNews : Greece expanding its energy exploration operation in eastern Mediterranean
• WorldOil : Turkey explores contested Mediterranean waters
• Diploweb : The Greco-Turkish dispute over the Aegean Sea : a possible solution ? 

Greenland ice sheet hides huge 'impact crater'

 A large impact crater beneath Hiawatha Glacier in northwest Greenland

From BBC by Jonathan Amos

What looks to be a large impact crater has been identified beneath the Greenland ice sheet.

The 31km-wide depression came to light when scientists examined radar images of the island's bedrock.

Localization with the GeoGarage platform (DGA nautical chart)

Space view: The semi-circular margin of the ice sheet traces the outline of the crater

Natural History Museum of Denmark

Investigations suggest the feature was probably dug out by a 1.5km-wide iron asteroid sometime between about 12,000 and three million years ago.

A map of the bedrock of Greenland.

It would be the most northerly crater on Earth

But without drilling through nearly 1km of ice to sample the bed directly, scientists can't be more specific.
"We will endeavour to do this; it would certainly be the best way to get the 'dead fish on the table', so to speak," Prof Kurt Kjær, from the Danish Museum of Natural History, told BBC News.

In a remote area of northwest Greenland, an international team of scientists has made a stunning discovery, buried beneath a kilometer of ice.

It’s a meteor impact crater, 300 meters deep and bigger than Paris or the Beltway around Washington, DC.

It is one of the 25 largest known impact craters on Earth, and the first found under any of our planet’s ice sheets.

The researchers first spotted the crater in July 2015, while they were inspecting a new map of the topography beneath Greenland's ice sheet that used ice-penetrating radar data primarily from Operation IceBridge, an ongoing NASA airborne mission to track changes in polar ice, and earlier NASA airborne missions in Greenland.

If confirmed, the crater would be the first of any size that has been observed under one of Earth's continental ice sheets.
The discovery is reported in the journal Science Advances.

Kurt Kjær collects sand transported from under the glacier

What does the crater look like?

The putative impact crater is located right on the northwest margin of the Greenland Ice Sheet, underneath what is known as Hiawatha Glacier.

Additional high-resolution radar imagery gathered by Prof Kjær's team clearly shows a circular structure that is elevated at its rim and at its centre - both classic traits.
But because the depression is covered by up to 980m of ice, the scientists have so far had to rely on indirect studies.

A map of the bedrock topography beneath the ice sheet

What is the supporting evidence?

Meltwaters running out from under Hiawatha Glacier into the Nares Strait carry sediments from the depression.
In these sediments are quartz grains which have been subjected to enormous shock pressures, of the type that would be experienced in an impact.

Quartz grains show evidence of having experienced shock pressures

Other river sediments have revealed unusual ratios in the concentrations of different metals.
"The profile we saw was an enrichment of rhodium, a depletion of platinum, and an enrichment of palladium," explained team-member Dr Iain McDonald, from Cardiff University, UK.
"We got very excited about this because we realised we weren't looking at a stony meteorite, but an iron meteorite - and not just any old iron meteorite; it had to be quite an unusual composition."

Such metal objects that fall to Earth are thought to be the smashed up innards of bodies that almost became planets at the start of the Solar System.

The signatures identified by Dr McDonald are relatively close to those in iron meteorite fragments collected at Cape York not far from the Hiawatha site. It's not inconceivable, the team argues, that the Cape York material represents pieces that came away from the main asteroid object as it moved towards its collision with Earth.

The Hiawatha Glacier cuts across the rim of the crater

What are the doubts?

One concerns the absence of any trace of the impact in several cores that have been drilled through the ice sheet to the south.
At the very least, these might have been expected to incorporate the dust that fell out of the sky after the event.

The other head-scratcher is the absence in the vicinity of the Hiawatha site of any rocky material that would have been ejected outwards from the crater on impact.

Prof Kjær says these missing signatures might be explained by a very shallow angle of impact that took most of the ejecta to the north.
And if the fall-out area was covered in ice, it's possible any debris was later transported away.
"We know that at one time the Greenland Ice Sheet was joined to the Canadian Ice Sheet, and flowed out into the Nares Strait. If you wanted to find this material today, you'd have to do deep drilling in the ocean," Prof Kjær explained.

A view of the bedrock below the ice facing northwest, toward the sea, shows the terrain of the crater.

In addition the rim surrounding the feature, the researchers behind the discovery also spotted a slight rise in the center.

Such a rise is a fairly common feature in impact craters, but not diagnostic of how the gape formed

Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA

What are the age constraints?

The team knows the crater must be older than roughly 12,000 years because the undisturbed ice layers above the depression can be lined up with the layers in drill cores that have been directly dated.

And they estimate an age younger than three million years based on an assessment of likely rock erosion rates, both within the crater and on nearby terrains. But the only way to get a definitive age for the crater would be to drill down and collect rocks for laboratory dating.

An artist's depiction of an iron asteroid hurtling through space

How does this connect with other ideas?

If the impact was right at near-end of the age window then it will surely re-ignite interest in the so-called Younger Dryas impact hypothesis.
The Younger Dryas was a period of strong cooling in the middle of the climatic warming that occurred as the Earth emerged from the height of last ice age.

An illustration of an airplane using radar to map the topography below the ice sheet.

Some have argued that an asteroid impact could have been responsible for this cooling blip - and the accompanying extinction of many animal groups that occurred at the same time across North America.
Others, though, have been critical of the hypothesis, not least because no crater could be associated with such an event.
The Hiawatha depression is likely now to fan the dying embers of this old debate.

Dr Mathieu Morlighem, a team-member from the University of California, Irvine, US, commented: "When you think about it, the bed below the ice sheets has to have impact craters that have not been explored yet, and there may even be some in Antarctica as well, but more radar measurements are necessary to locate them, and dating them is extremely challenging."

Links :

• Uncovering offers a window into just how common large meteoric strikes on earth might be after all. Because, the Earth is littered with this size of crater. In 2001, the University of New Brunswick counted 190 total known earth impact structures. In 2009, University of Russia counted 899 total impact structures on earth. Today's Google map on the web lists EID's 2001-era 190 crater list of structures, only. https://web.archive.org/web/20090716232605/http://omzg.sscc.ru/impact/index1.html
• The Guardian : Impact crater 19 miles wide found beneath Greenland glacier
• CNN : Scientists confirm massive impact crater beneath Greenland's ice
• NASA : International Team, NASA Make Unexpected Discovery Under Greenland Ice
• GeoGarage blog : Seafloor map shows why Greenland's glaciers melt ... / New Greenland maps show more glaciers at risk / Map provides high-resolution look at nearly entire ...