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Sunday, January 17, 2021
On August 25th, 1875 Captain Matthew Webb became the first person to swim across the English Channel : here is a map of his route
On August 25th, 1875 Captain Matthew Webb became the first person to swim across the English Channel.
Here is a map of his route.
The tide carries him northward, then turns and brings him south again.
The tide carries him northward, then turns and brings him south again.
From History
On August 24, 1875, Captain Matthew Webb of Great Britain becomes the first man to successfully swim the English Channel without assistance.
On August 24, 1875, Captain Matthew Webb of Great Britain becomes the first man to successfully swim the English Channel without assistance.
After the feat, Webb became an international celebrity, admired for both his prowess in the water and his penchant for risk-taking.
Born in Shropshire, England on January 19, 1848, Webb taught himself to swim in the River Severn at Coalbrookdale.
Born in Shropshire, England on January 19, 1848, Webb taught himself to swim in the River Severn at Coalbrookdale.
At just 12 years old, he enlisted as a merchant seaman, and eventually was named captain of the steamship Emerald.
Webb had a well-deserved reputation for recklessness, and often had trouble convincing sailors to remain in his employ.
In August 1872, he became a hero in England when, while traveling on a ship, he dove into the Atlantic to rescue a fellow passenger who fell overboard.
Although the man drowned, Webb emerged unscathed 35 minutes later and was rewarded with medals of bravery for his efforts.
He then embarked on a career as a professional distance swimmer, taking huge risks in order to add to his fame and fortune.
After hearing of a failed attempt to swim the English Channel by British swimmer J.B. Johnson in 1873, Webb set his sights on becoming the first man to swim the treacherous body of water without assistance.
He made his first attempt on August 12, 1875, but was stymied by high winds and bad conditions.
Unfazed, he tried again less than two weeks later.
After covering himself with porpoise oil to keep warm, Webb, trailed by a flotilla of three boats, entered the water near Dover’s Admiralty Pier.
After covering himself with porpoise oil to keep warm, Webb, trailed by a flotilla of three boats, entered the water near Dover’s Admiralty Pier.
Admiralty nautical chart of the south coast of England from Dungeness to the Thames including Dover Strait.
Surveyed by Captain Frederick Bullock.
The coast of France from the Pilote Francaise including the Varne & Ridge 1848.
Though he was stung by a jellyfish eight hours into his attempt, he persevered after being soothed by a nip of brandy.
He swam into the out-rushing tide toward Cape Gris-Nez, which is now often used as the starting point for Channel swims.
Finally, after 21 hours and 45 minutes of swimming against the tide—the equivalent of 39 miles–he waded onto the beach at Calais at 10:40 a.m., the morning after he began his swim, exhausted.
His achievement was celebrated all over the world.
On July 24, 1883, Webb attempted his final stunt: a swim across the Niagara River, downriver from Niagara Falls.
On July 24, 1883, Webb attempted his final stunt: a swim across the Niagara River, downriver from Niagara Falls.
Many warned him the stunt was suicide, and, unfortunately for Webb, they were right.
Webb drowned in the whirlpool approximately 10 minutes after entering the water.
His body was found four days later.
Links :
- Colm Breathnach's swimming blog : the English Channel
- BBC : Sarah Thomas: Woman first to swim Channel four times non-stop
- TrainDaly : Coaching a swim across the English Channel
Saturday, January 16, 2021
Image of the week : In a year's worth of photos, the Sentinel-1 satellites materialise the Channel maritime motorway
From Ciel&espace
Seen by satellite radar, ships transiting between France and England draw a double line that evokes the Brexit, in force for the new year.
On 31 December 2020 at midnight (23:00 GMT), the United Kingdom leaves the European Union.
An image taken by the two satellites Sentinel-1A and 1B, of the European Copernicus programme, seems to symbolise the event: it is the accumulation of radar images taken throughout 2020 over the Channel.
Able to see through the clouds, the Sentinel-1 radar allows all the ships in permanent transit between France and England to be seen.
Adding up the photos gives an astonishing materialisation of this maritime route, one of the busiest in the world...
And symbolically, this route evokes the separation between Great Britain and the Continent, which was actuated by the Brexit, and which becomes a reality from the first second of 2021.
The Channel maritime motorway has two lanes to avoid collisions between the many ships using it.
The North Sea is studded with pre-polar installations and wind farms. Credit: ESA.
Already in 2019, the European Space Agency had published a similar image that accumulated photos taken over three years, between 2016 and 2018.
The English Channel in 2020, as seen by @CopernicusEU's Sentinel-1 imaging radar. This maximum reflectivity composite shows the year in shipping lanes, offshore wind farms, &c. pic.twitter.com/9WjxEkDcB1
— Tim Wallace (@wallacetim) December 31, 2020
In the 2020 image, which was broadcast on 31 December on Twitter by journalist Tim Wallace of the New York Times, in addition to the cargo ships transiting the English Channel, the ferries sailing between Calais and Dover were also shown, as well as the wind farms installed at sea, which drew geometric patterns.
A zoom on the Belwind wind farm off the coast of the Netherlands reveals the 110 wind turbines installed at sea between 2010 and 2017.
Credit: ESA.
Friday, January 15, 2021
Climate change: Weakened 'ice arches' speed loss of Arctic floes
From BBC by Jonathan Amos
Look down on the Arctic from space and you can see some beautiful arch-like structures sculpted out of sea-ice.
They form in a narrow channel called Nares Strait, which divides the Canadian archipelago from Greenland.
As floes funnel southward down this restricted conduit, they ram up against the coastline to form a dam, and then everything comes to a standstill.
"They look just like the arches in a gothic cathedral," observes Kent Moore from the University of Toronto.
"And it's the same physics, even though it's ice.
The stress is being distributed all along the arch and that's what makes it very stable," he told BBC News.
But the UoT Mississauga professor is concerned that these "incredible" ice forms are actually being weakened in the warming Arctic climate.
They're thinning and losing their strength, and this bodes ill, he believes, for the long-term retention of all sea-ice in the region.
Directly to the north of Nares Strait is the Lincoln Sea.
It's where you'll find some of the oldest, thickest floes in the Arctic Ocean.
It's this ice that will be the "last to go" when, as the computer models predict, the Arctic becomes ice-free during summer months sometime this century.
There are essentially two ways this old ice can be lost.
It can be melted in place in the rising temperatures or it can be exported.
And it's this second mode that's in play in Nares Strait.
The 40km-wide channel's arches act as a kind of valve on the amount of sea-ice that can be pushed out of the Arctic by currents and winds.
When stuck solidly in place, typically from January onwards - the arches shut off all transport (sea-ice can still be exported from the Arctic via the Fram Strait, which is the passage between eastern Greenland and Svalbard).
But what Prof Moore's and colleagues' satellite research has shown is that these structures are becoming less reliable barriers.
"They look just like the arches in a gothic cathedral," observes Kent Moore from the University of Toronto.
"And it's the same physics, even though it's ice.
The stress is being distributed all along the arch and that's what makes it very stable," he told BBC News.
But the UoT Mississauga professor is concerned that these "incredible" ice forms are actually being weakened in the warming Arctic climate.
They're thinning and losing their strength, and this bodes ill, he believes, for the long-term retention of all sea-ice in the region.
Directly to the north of Nares Strait is the Lincoln Sea.
It's where you'll find some of the oldest, thickest floes in the Arctic Ocean.
It's this ice that will be the "last to go" when, as the computer models predict, the Arctic becomes ice-free during summer months sometime this century.
There are essentially two ways this old ice can be lost.
It can be melted in place in the rising temperatures or it can be exported.
And it's this second mode that's in play in Nares Strait.
The 40km-wide channel's arches act as a kind of valve on the amount of sea-ice that can be pushed out of the Arctic by currents and winds.
When stuck solidly in place, typically from January onwards - the arches shut off all transport (sea-ice can still be exported from the Arctic via the Fram Strait, which is the passage between eastern Greenland and Svalbard).
But what Prof Moore's and colleagues' satellite research has shown is that these structures are becoming less reliable barriers.
Nares strait with the GeoGarage platform (NGA nautical raster charts)
They are forming for shorter periods of time, and the amount of frozen material allowed to pass through the strait is therefore increasing as a consequence.
"We have about 20 years of data, and over that time the duration of these arches is definitely getting shorter," Prof Moore explained.
"We show that the average duration of these arches is decreasing by about a week every year.
They used to last for 250-200 days and now they last for 150-100 days.
And then as far as the transport goes - in the late 1990s to early 2000s, we were losing about 42,000 sq km of ice every year through Nares Strait; and now it's doubled: we're losing 86,000 sq km."
Prof Moore says we need to hang on to the oldest ice in the Arctic for as long as possible.
If the world manages to implement the ambition of the Paris climate accord and global warming can be curtailed and reversed, then it's the thickest ice retained along the top of Canada and Greenland that will "seed" the rebound in the frozen floes.
The area of oldest, thickest ice, he adds, is also going to be an important refuge for those species that depend on the floating floes for their way of life - the polar bears, walruses and seals.
"My concern is that this last ice area may not last for as long as we think it will.
This is ice that is five, six, even 10 years old; so if we lose it, it will take a long time to replenish even if we do eventually manage to cool the planet."
Prof Moore and colleagues have published their latest research in the journal Nature Communications.
Links :
- BBC : Satellites capture Arctic ice shelf split / 'The sea-ice is dying': Historic Arctic trip ends / Arctic sea-ice shrinks to near record low extent
- Phys : Ice arches holding Arctic's 'last ice area' in place are at risk, researcher says
- Science Alert : The Arctic's 'Last Ice Area' Is Showing Worrying Signs of Fragility
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