New nautical chart on Svalbard (Kartverket Norway) nr. 541 Nordporten–Sjuøyane, May 4, 2017
From Hydro
As members or associate members of the Arctic Regional Hydrographic Commission (ARHC) and as Member States of the International Hydrographic Organization (IHO), the government Hydrographic Offices of Canada, Denmark, Finland, Iceland, Norway, the Russian Federation and the United States of America wish to highlight the significant limitations and risks associated with marine navigation in the Arctic.
While official nautical charts are produced by government hydrographic offices and are based on the latest information available, substantial areas still rely on limited, outdated, or insufficient depth and other data.
Sjokartverket survey vessel Hydrograf in the Arctic with polar bear.
Image courtesy: Norwegian Hydrographic Service.
Plan and Sail with Care
Due to the significant limitations of Arctic charting, all mariners in Arctic waters are required to plan well in advance of any prospective voyages, to understand their environment, and to exercise extreme caution when on the water, in order to minimise the associated high levels of risk.
Caution is equally essential when navigating with Electronic Navigational Charts (ENC), as these official digital charts are based on the same limited or insufficient data as the official paper or electronic equivalent charts.
Navigating outside areas supported by modern or adequately surveyed data, and without advanced and comprehensive voyage planning, ice experience, knowledge, and precautions, can result in the loss of human life and severe damage to property and the environment.
To fulfil the relevant requirements of demonstrating that they have recognised and mitigated the risks, as well as exercised due diligence in the operation of their vessels, all mariners and ship operators should take note of the warnings set out here and in other references, including in the International Code for Ships Operating in Polar Waters (The Polar Code).
Interested readers are encouraged to contact the IHO Secretariat or the Hydrographic Offices of the ARHC Member States with any comments or feedback, as part of the efforts of the Arctic hydrographic community to improve safety of navigation and operations in the region.
Did you know that the first solo circumnavigation of the globe was completed in Newport, Rhode Island on this day 119 years ago?
Captain Joshua Slocum, a native of Novia Scotia, completed the feat on June 27th, 1898.
On April 24, 1895, at the age of 51, he departed Boston in his tiny sloop Spray , a 36′ 9″ gaff rigged sloop oyster boat, and sailed around the world single-handed.
In his famous book, Sailing Alone Around the World, now considered a classic of travel literature, he described his departure in the following manner:
“I had resolved on a voyage around the world, and as the wind on the morning of April 24, 1895 was fair, at noon I weighed anchor, set sail, and filled away from Boston, where the Spray had been moored snugly all winter. The twelve o’clock whistles were blowing just as the sloop shot ahead under full sail. A short board was made up the harbor on the port tack, then coming about she stood to seaward, with her boom well off to port, and swung past the ferries with lively heels. A photographer on the outer pier of East Boston got a picture of her as she swept by, her flag at the peak throwing her folds clear. A thrilling pulse beat high in me. My step was light on deck in the crisp air. I felt there could be no turning back, and that I was engaging in an adventure the meaning of which I thoroughly understood.”
According to Slocum in Sailing Alone Around the World; After an extended visit to his boyhood home at Brier Island and visiting old haunts on the coast of Nova Scotia, Slocum departed North America at Sambro Island Lighthouse near Halifax, Nova Scotia on July 3, 1895. Slocum intended to sail eastward around the world, using the Suez Canal, but when he got to Gibraltar he realized that sailing through the southern Mediterranean would be too dangerous for a lone sailor because of the piracy that still went on there at that time. So he decided to sail westward, in the southern hemisphere. He headed to Brazil, and then the Straits of Magellan. At that point, he was unable to start across the Pacific for forty days because of a storm. Eventually, he made his way to Australia, sailed north along the east coast, crossed the Indian Ocean, rounded the Cape of Good Hope, and then headed back to North America. Slocum navigated without a chronometer, instead relying on the traditional method of dead reckoning for longitude, which required only a cheap tin clock for approximate time, and noon-sun sights for latitude. On one long passage in the Pacific, Slocum also famously shot a lunar distance observation, decades after these observations had ceased to be commonly employed, which allowed him to check his longitude independently. However, Slocum’s primary method for finding longitude was still dead reckoning; he recorded only one lunar observation during the entire circumnavigation. Slocum normally sailed the Spray without touching the helm. Due to the length of the sail plan relative to the hull, and the long keel, the Spray was capable of self-steering (unlike faster modern craft), and he balanced it stably on any course relative to the wind by adjusting or reefing the sails and by lashing the helm fast. He sailed 2,000 miles (3,200 km) west across the Pacific without once touching the helm.
More than three years later, on June 27, 1898, he arrived in Newport, having circumnavigated the world, a distance of more than 46,000 miles.
Slocum’s return went almost unnoticed.
The Spanish–American War, which had begun two months earlier, dominated the headlines.
After the end of major hostilities, many American newspapers published articles describing Slocum’s amazing adventure.
This historic achievement made him the patron saint of small-boat voyagers, navigators and adventurers all over the world.
“Single-handed” does not imply “non-stop”, so a single-handed circumnavigation counts as such even with stops, as in Joshua Slocum’s voyage
On November 14, 1909, Slocum set sail for the West Indies on one of his usual winter voyages.
He had also expressed interest in starting his next adventure, exploring the Orinoco, Rio Negro and Amazon Rivers.
Slocum was never heard from again.
In July 1910, his wife informed the newspapers that she believed he was lost at sea.
In 1924, Joshua Slocum was declared legally dead.
We now have a map of plate tectonics for the period 1,000-520 million years ago.
The colours refer to where the continents lie today.
Light blue = India, Madagascar and Arabia, magenta = Australia and Antarctica, white = Siberia, red = North America, orange = Africa, dark blue = South America, yellow = China, green = northeast Europe.
From The Conversation by Alan Collins (University of Adelaide) and Andrew Merdith (University of Sydney)
Earth is estimated to be around 4.5 billion years old, with life first appearing around 3 billion years ago.
To unravel this incredible history, scientists use a range of different techniques to determine when and where continents moved, how life evolved, how climate changed over time, when our oceans rose and fell, and how land was shaped.
Tectonic plates – the huge, constantly moving slabs of rock that make up the outermost layer of the Earth, the crust – are central to all these studies.
Along with our colleagues, we have published the first whole-Earth plate tectonic map of half a billion years of Earth history, from 1,000 million years ago to 520 million years ago.
The time range is crucial.
It’s a period when the Earth went through the most extreme climate swings known, from “Snowball Earth” icy extremes to super-hot greenhouse conditions, when the atmosphere got a major injection of oxygen and when multicellular life appeared and exploded in diversity.
Now with this first global map of plate tectonics through this period, we (and others) can start to assess the role of plate tectonic processes on other Earth systems and even address how movement of structures deep in our Earth may have varied over a billion year cycle.
The Earth moves under our feet
The modern Earth’s tectonic plate boundaries are mapped in excruciating detail.
Modern plate tectonic boundaries.But how do we map the Earth like this in the past? NASA's Earth Observatory
In the modern Earth, global positioning satellites are used to map how the Earth changes and moves.
We know that up-welling plumes of hot rock from over 2,500 km deep in the planet’s mantle (the layer beneath the Earth’s crust) hit the solid carapace of the planet (the crust and the top part of the mantle).
This forces rigid surface tectonic plates to move at the tempo of a fingernail’s growth.
On the other side of the up-welling hot rock plumes are areas known as subduction zones, where vast regions of the ocean floor plunge down into the deep Earth.
Eventually these down-going oceanic plates hit the boundary between the core and mantle layers of Earth, about 2,900 km down.
They come together, forming thermal or chemical accumulations that eventually source these up-welling zones.
It’s fascinating stuff, but these processes also create problems for scientists trying to look back in time.
The planet can only be directly mapped over its last 200 million years.
Before that, back over the preceding four billion years, the majority of the planet’s surface is missing, as all the crust that lay under the oceans has been destroyed through subduction.
Oceanic crust just doesn’t last: it’s constantly being pulled back deep into the Earth, where it’s inaccessible to science.
This animation shows the plate tectonic evolution of the Earth from the time of Pangea, 240 million years ago, to the formation of Pangea Proxima, 250 million years in the future. The animation starts with the modern world then winds it way back to 240 million years ago (Triassic).
The animation then reverses direction, allowing us to see how Pangea rifted apart to form the modern continents and ocean basins.
When the animation arrives back at the present-day, it continues for another 250 million years until the formation of the next Pangea, "Pangea Proxima". Notice how the areas of green (land), brown (mountains), dark blue (deep sea), and light blue (shallow seas on continents), changes throughout time.
These changes are the result of mountain-building, erosion, and the rise and fall of sea level throughout time.
The white patches near the pole are the expanding and contracting polar icecaps.
Mapping the Earth in deep time
So what did we do to map the Earth in deep time?
To get at where plate margins were and how they changed, we looked for proxies – or alternative representations – of plate margins in the geological record.
We found rocks that formed above subduction zones, in continental collisions, or in the fissures where plates ripped apart.
Our data came from rocks found in locations including Madagascar, Ethiopia and far west Brazil.
The new map and associated work is the result of a couple of decades of work by many excellent PhD students and colleagues from all over the world.
We now have more details, and a view to way further back in geological time, than were previously available for those studying the Earth.
Using other methods, the latitudes of continents in the past can be worked out, as some iron-bearing rocks freeze the magnetic field in them as they form.
This is like a fossil compass, with the needle pointing into the ground at an angle related to the latitude where it formed — near the equator the magnetic field is roughly parallel to the Earth’s surface, at the poles it plunges directly down.
You can see this today if you buy a compass in Australia and take it to Canada: the compass won’t work very well, as the needle will want to point down into the Earth.
Compass needles are always balanced to remain broadly horizontal in the region that they are designed to work in.
But, these so-called “palaeomagnetic” measurements are hard to do, and it is not easy finding rocks that preserve these records.
Also, they only tell us about the continents and not about plate margins or the oceans.
The cool, rigid, outer layer of the earth, the lithosphere,
is broken into massive plates along discrete boundaries.
What are these plates, and what do the boundaries represent?
Why map ancient plate tectonics?
The lack of ancient tectonic maps has posed quite a problem for how we understand our Earth.
Tectonic plates influence many processes on Earth, including the climate, the biosphere (the sphere of life on the outer part of the planet), and the hydrosphere (the water cycle and how it circulates around the planet and how its chemistry varies).
By simply redistributing tectonic plates, and thereby moving the positions (the latitudes and longitudes) of continents and oceans, controls are placed on where different plants and animals can live and migrate.
Plate boundary locations also govern how ocean currents redistribute heat and water chemistry. Different water masses in the ocean contain subtly different elements and their various forms, known as isotopes.
For example, water in the deep oceans was often not at the surface for many many thousands of years, and has different composition from the water presently on the ocean’s surface.
This is important because different water masses contain different amounts of nutrients, redistributing them to different parts of the Earth, changing the potential for life in different places.
Tectonic plates also influence how much of the Sun’s radiation gets reflected back out to space, changing the Earth’s temperature.
How fast tectonic plates move have also varied over time.
At different periods in Earth history there were more mid-ocean volcanoes than there are today, creating water movement such as pushing up ocean waters over the continents.
At these times, some types of volcanic eruptions were more frequent, pumping more gas into the atmosphere.
Mountain ranges form as tectonic plates collide, which affect oceanic and atmospheric currents as well as exposing rocks to be eroded.
This locks up greenhouse gases, and releases nutrients into the ocean.
Understand ancient plate tectonics and we go someway to understanding the ancient Earth system. And the Earth as it is today, and into the future.
The Kiwi owner of a yacht shipwrecked on a reef in Fiji says his nautical charts told him the reef was about 5km away - just before the boat hit it.
Four New Zealanders were on the yacht Jungle when it ran aground on Friday morning, stranding them on a remote atoll.
Geoff Marsland, founder of Wellington's iconic Havana Coffee, and Fidel's Cafe co-owner Roger Young were aboard, with yacht owner Peter McLean and his son.
The yacht left Picton on June 15, bound for Tonga.
The crew changed tack for Fiji when the boat's backstay broke.
Tuvana-I-Ra on the GeoGarage platform (SHOM chart)
Tuvana-I-Ra on the GeoGarage platform (UKHO 2691-1 chart)
Tuvana-I-Ra on the GeoGarage platform (Linz chart)
Tuvana-I-Ra on the GeoGarage platform (83580A NGA nautical chart, scale 1:350 000)
note : the shift with positionning (around 1,75 NM between the nautical map and the satellite imagery)
Tuvana-I-Ra with Google satellite imagery
Early on Friday it hit the isolated reef off Tuvana-I-Ra, more than 400km from Fiji's capital, Suva.
The men managed to make it ashore but their boat was smashed up on the reef.
Marsland told Fairfax the ordeal was like "Survivor in real life", with the four inhabitants of the island initially thinking the men were armed pirates.
But after they found out the men were Kiwis they were extremely hospitable, cooking up a couple of wild chickens for dinner and providing beds and warm clothes.
In return the Kiwis gave their hosts what they could salvage from the yacht including linen, alcohol and a bicycle, Marsland told Fairfax.
In an interview with the Fiji Sun boat owner Peter McLean said the sailors were navigating the reef at high tide when the accident happened.
"The plotter and the radar both said we were three miles off but the two plotters were incorrect by three miles so we just hit the edge of the reef," he said.
"The charts are outdated, they all need to be updated. It should have been done before now . . . If the charts were correct it never would have happened."
Fiji Navy patrol boat the Kula picked the four men up on Saturday and they arrived in Suva about 8.30 this morning.
All four are now safe and well in Suva, the New Zealand High Commission said.
High Commissioner Mark Ramsden says the men were looked after very well by the Fiji Navy and had not requested consular assistance with accommodation or flights home.
You can notice some shift in the display of the ship localization, probably due to the unspecified manually registered data setting sent by the QM2 AIS transceiver (XY offset of the AIS GPS antenna position compared to the ship geometry) : see reference point. The width for display is the waterline beam (41 m) and not the one at the bridge level (45 m). Length: 1,132 ft (345.03 m) Beam :135 ft (41 m) waterline VS 147.5 ft (45.0 m) extreme (bridge wings) so a difference of width of 4 m, around 8% of the Joubert lock width. Ship dimensions and AIS GPS antenna reference point should be obtained from AIS Class A within a 1 minute (in worst cases it might be up to 6 minutes by AIS IEC 61993 Ed2 standard). It is recommended to use the ‘Conning Station’ position at the midship line, Conning Station reference point (CRP) is the main reference point and GPS data recalculates to the specified Conning Station Position.
/media.nzherald.co.nz/webcontent/image/jpg/201726/19490201_1492691987455733_1951671290_o_master.jpg)
