Trevillett Mill and Cottages, self catering holiday accommodation exclusively located in Rocky Valley, Tintagel, North Cornwall



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The science of waves

As lockdown eases and summer draws holiday makers to the beach, many people will enjoy the sea, whether paddling in the waves or being more adventurous and taking to surf and body boards. We take these constant but etherial phenomena for granted, but have you ever thought what causes waves and why conditions can be so different from day to day, or even hour to hour?

Ocean waves are generated by the wind.  When the wind blows across the water surface, the friction between the wind and the surface ruffles the surface of the sea.  This causes little, ‘capillary’ waves to be created.  If the wind continues to blow on these little undulations, they get bigger.

There are three factors that are needed for big waves to be created:  You need a strong wind, blowing for a long time, over a long distance.  The requirement for a long fetch (the distance upon which the wind blows) and no obstacles is why the biggest waves are generated in the open ocean.

Waves can travel long distances and so may end up thousands of miles from the original storm that formed them. Scientific studies have tracked waves that were started off the coast of New Zealand all the way to the coast of California.

Swell Waves

There are two fundamentally different types of wave in the sea.  There are wind-driven waves, which are the ones generated, grown and pushed along by the wind.  Once they have left the storm area, they organise themselves into swell waves.  So wave is the general term and swell is a specific term, meaning a wave generated by distant winds.

The swell waves propagate away from the generating area and travel until they reach shallower water.  So even if it’s a clam day, your local beach might still have large swell waves that have come from a distant storm.

Waves travel about 20 to 30 miles an hour in the open ocean.  So big waves can take 2 to 3 days to get to Cornwall, by which time conditions at the coast might be calm and sunny.  This is one of the most misunderstood things about waves – you can still have big waves even when local winds are calm!

Types of breaker

When waves come into shallower water, they break.  The wave reaches a point when the crest is travelling faster than the trough (due to friction against the beach), so the wave becomes unstable and breaks.  There are two types of breaker: a spilling breaker and a plunging breaker.

A spilling breaker is a gentle breaking wave and occurs on flat, gently sloping beaches such as Polzeath.  Spilling breakers topple over gently and spill shorewards, often accompanied by an on-shore wind.  These waves are popular with learner surfers.

The converse is the plunging breaker, which breaks in a more violent way, when the transition in seabed from steep to shallow is quicker.

The plunging breaker curls over at the top and forms a tube that good surfers can ride in.  The ideal combination is a steep slope for the wave to break on together with an off-shore wind that helps hold the wave up, delaying it break.  On UK beaches, this often occurs at low tide because the low water mark beaches tend to drop off an make a steeper slope.  You can see this on the popular Fistral beach.  

Local variations

Various factors on individual beaches will affect waves, including the shape of the beach, the sea bottom and other obstructions such as islands or curved headlands.  In the summer, smaller waves bring in sand, creating sandbanks that waves break around.  This is good for surfing, but the rip currents that develop between the sandbanks are hazardous for bathers and learner surfers.

Rogue waves

A ‘rogue’ wave occurs when waves that are travelling in different directions come together and combine their heights into one larger wave.  This sudden increase in size can be hazardous for water users out at sea. 

Closer to shore, waves typically arrive in sets (a group of a few large waves, one after another) every few minutes, with a few smaller wave in between.  But a particularly large set is often responsible for washing anglers and coastal walkers from rocks into the sea.

Forecasting waves

In the past, forecasting waves required analysis of weather charts, tide, wind and local conditions.  Now there are forecasting apps just a click away.  These include magicseaweed.com and windy.com.

 

What is Juneteenth and why are you hearing about it now?

Juneteenth is the commemoration of the ending of slavery in the United States, but the day will take on an extra meaning in the wake of George Floyd's killing. 

June 19 marks the day back in 1865 when Major General Gordon Granger landed at Galveston, Texas, to announce the civil war was over and the final group of African Americans were now free.

The day came more than two years after President Lincoln’s Emancipation Proclamation - which had become official on January 1, 1863.

It is believed the delay between the proclamation and announcing the end of slavery in Texas was due to the minimal number of Union troops to enforce the new Executive Order.

But with the surrender of General Lee in April of 1865, and the arrival of General Granger’s regiment, the forces were finally strong enough to influence and overcome the resistance.

General Granger read out to the people of Texas - General Order Number 3.

It read: "The people of Texas are informed that in accordance with a Proclamation from the Executive of the United States, all slaves are free. 

"This involves an absolute equality of rights and rights of property between former masters and slaves, and the connection heretofore existing between them becomes that between employer and hired labourer."

The name - Juneteenth - is a combination of June and Nineteenth and is also known as Emancipation Day, Juneteenth Independence Day and Black Independence Day.

The day is remembered in America with celebrations and the descendants of former slaves making an annual pilgrimage back to Galveston on this date.

World Oceans Day 8th June

Monday 8th June 2020 is nominated "World Oceans Day", when people around our blue planet celebrate and honor our ocean, which connects us all. It's an opportunity to get together with your family, friends, community, and millions of others around our blue planet to start creating a better future. 

For 2020, World Oceans Day is growing the global movement to call on world leaders to protect 30% of the world's ocean by 2030 - a campaign called 30x30. By safeguarding at least 30% of our ocean through a network of highly protected areas we can help ensure a healthy home for both marine and human life.

A global petition has been launched to help apply pressure to national governments that can be signed at  www.worldoceansday.org.

There are number of global events taking place this year and you can join in with something as simple as your own beach clean.

By working together, we can help protect and restore our shared ocean. Join this growing global celebration on 8 June, but why not keep it going all year round!

The hidden magic of bluebells

This is the time of year that Rocky Valley turns blue in a wonderful carpet of bluebells. 

Bluebells are unmistakable bell-shaped perennial herbs. They actually spend the majority of their time underground as bulbs, emerging, often in droves, to flower from April onwards.

The UK contains up to 49% of the world’s population of bluebells; although they are threatened by habitat loss as they love ancient or natural woodland.

The bluebell is the flower of St George, as it usually starts to bloom around St George’s Day on 23rd April and has many names: English bluebell, wild hyacinth, wood bell, bell bottle, Cuckoo’s Boots, Wood Hyacinth, Lady’s Nightcap and Witches’ Thimbles.

In folklore, bluebells were said to ring when fairies were summoning their kin to a gathering; but if a human heard the sound, it would be their death knell.  Not surprisingly, it was considered unlucky to trample on a bed of bluebells, because you would anger the fairies resting there.  

There’s an interesting belief that wearing a garland of bluebells will induce you to speak only the truth.

No garland today, so you’ll just have to believe that these are bluebell truths:

  • Mediaeval archers used to use the sap from bluebells to stick their feathers (fletches) to their arrows. It has also been used in bookbinding because it would repel attacks by insects.
  • It is against the law to intentionally pick, uproot or destroy bluebells.
  • If you plant bluebells, you should make sure it's the English bluebell, not the Spanish version. This is a larger and more vigorous plant and could out-compete our delicate native flower
  • Bluebell colonies take a long time to establish - around 5-7 years from seed to flower.
  • Bluebells can take years to recover after footfall damage. If a bluebell’s leaves are crushed, they die back from lack of food as the leaves cannot photosynthesise. 

So next time you happen across this pretty little flower, remember, there’s a lot more to the bluebell than you think and if you hear bells ringing…run!


 

 

Amazing meteor shower tonight, Monday and Tuesday night

Lockdown Britain is set for a twinkling treat as a meteor shower is set to light up the skies this week.

Turn your gaze skyward out your windows or grab a blanket and set up the deckchairs outdoors at your home to take in the spectacular lightshow.

Anywhere from ten to hundreds of meteors an hour are predicted to glitter across the Northern Hemisphere's night skies this week.

The annual meteor shower is expected to peak on Tuesday night and the best viewing time is just before dawn on Wednesday.

What is the Lyrid Meteor Shower and when can you see it?

The spectacular light shower is already underway but will be most visible in the United Kingdom and the United States early this week.

Experts say the peak viewing time will be late Tuesday night and into the early hours of Wednesday, with observations are affected by the phases of the moon and local weather conditions.

The Lyrid Meteor Shower occurs every April - putting on a spectacular light-show for stargazers.

Shooting stars appear as dust from the Comet C/1861 G1 Thatcher and interact with the Earth’s atmosphere.

When this dust enters Earth’s atmosphere, it burns up, producing a trail of light through the sky.

It takes its name from the Lyra constellation, from which the meteors appear to radiate.

While it is due to start tonight, the peak of the Lyrid meteor shower will be overnight on April 21-22, NASA meteor expert Bill Cooke told Space.com.

The Lyrids will be visible beginning at about 10:30pm, but are best viewed in the darkness after midnight and when urban lights have been switched off as households turn in for bed.

The best time to watch is after midnight and before the light of dawn, the expert said.

Check the weather forecast in your area to determine the prime time overnight to skygaze.

The phenomenon's peak visibility time of Tuesday night and early Wednesday morning is due to the phase of the moon.

It will be a thin crescent only about two days from the new moon at that time, Mr Cooke said, so the moonlight won't drown out the light-show.

Visibility will depend on how clear and dark the night sky where you live is, Cooke said.

 

Pink Supermoon

The biggest and brightest full moon of the year will rise over the skies of the UK tonight, offering the best chance to view a supermoon in 2020.

April's supermoon – officially referred to as a perigean full moon – will be the third month in a row for the rare celestial event. It occurs when the full moon is at its closest point to Earth in its monthly orbit.

On 7-8 April, the moon will get as close as 356,907km (221,772 miles) to Earth, making it appear bigger and brighter in the night's sky.

The time of year means this full moon is known in folklore as the 'Pink moon', as it usually coincides with spring flower blossoms.

The best time and date to see the supermoon is at moonrise on Tuesday and at moonset on Wednesday, when it is close to the horizon.

This is due to an optical illusion that makes it appear even bigger due to its relative size to buildings and objects on the horizon. The supermoon's peak illumination will take place just after 6pm GMT tonight, though it may not be visible until after sunset.

The term was first coined by astrologer Richard Nolle in 1979, who defined a supermoon as any full moon that was within 90 per cent of its closest approach.

The coinage and use of the term has been criticised by astronomers, however some welcome it as a way to encourage interest in astronomy.  But supermoons aren’t hype, they’re special. 

The supermoon will also have an effect on the Earth’s oceans, with the extra gravitational pull from the moon creating extra-high tides.

People living along the coast will notice them one or two days after the supermoon has passed, though any risk of flooding is unlikely unless the high tides are combined with severe weather.

Clear skies and reduced air pollution due to the coronavirus lockdown means April’s supermoon could be one of the best ever times to view a supermoon.

 

 

 

Minimum sizes that apply to recreational fishing in Cornwall

There have been significant changes made to the management of fisheries at a European level which will affect those fishing in the Cornwall Inshore Fisheries and Conservation Authority (IFCA) district in a number of ways.  One of the significant changes resulting from the new technical measures relates to recreational fishing.

CHANGES FOR RECREATIONAL FISHING

Under the new EU regulation, there are no longer any European minimum sizes for sea fish applied to recreational fishing.  However, the Marine Management Organisation (MMO) has said that it will apply the 42cm minimum conservation reference size for bass to recreational fishing.

The only minimum sizes that apply to recreational fishing in the Cornwall IFCA district are prescribed under our Specified Fish Sizes byelaw, and other byelaws for various shellfish species.

For recreational fishing, the following minimum sizes apply within the Cornwall IFCA district (with some small exceptions, as described below) Please note these sizes also apply to the commercial sector except where the Landing Obligation is applied.

FIN FISH    

Length 

Conger Eel          58 centimetres

Hake                    30 centimetres

Grey Mullet          20 centimetres

Red Seabream    25 centimetres

Black Seabream  23 centimetres

Red Mullet           15 centimetres

Witch Flounder    28 centimetres

Dab                      15 centimetres

Lemon Sole          25 centimetres

Flounder               25 centimetres

Megrim                 25 centimetres

Brill                       30 centimetres

Turbot                   30 centimetres 

SHELLFISH CARAPACE

Crawfish                          110mm

Edible Crab female          150mm

Edible Crab male             160mm

Spider crab                      130mm

Lobster                              90mm 

Mussels                             50mm shell length

The sizes listed above result from byelaws inherited from the former Cornwall Sea Fisheries Committee and therefore, do not apply to the whole of the larger Cornwall IFCA district, principally within the rivers and estuaries.  

In addition to the above shellfish minimum sizes, please be aware that cockles that are removed from Cornish rivers and estuaries must not pass through a space of 20mm width.

SPEARFISHING 

It is an offence to catch or harvest marine species using any type of projectile, including handheld spears and spear guns used in recreational fishing from dusk till dawn or when using an aqualung.

Star of wonder 

What is the star next to the moon this time of year and why is it so bright?  The light isn’t actually a star, it’s in fact a planet - Venus.

It’s not the flashiest celestial event, and it’s far from the rarest, but the juxtaposition of the crescent moon and Venus tonight will be worth a look.

If you live in the Northern Hemisphere and you’ve got a clear sky Thursday, look to the southwest and you’ll see a very bright Venus alongside the crescent moon.  With the moon just a thin fingernail, Venus will stand out in the night sky.

Venus — the third-brightest object visible from the Earth, after the sun and moon — is currently appearing as “the evening star.” It is approaching its greatest evening elongation of the year, the point at which, from an Earthly vantage, it appears farthest from the sun.  

When it is on the far side of the Sun, Venus can’t be seen, but as it comes round, getting closer to Earth, it becomes brighter and brighter, reflecting light from the Sun.  As it gets closer to us it is visible in the evening, then when it passes its closest point and moves away again it is visible in the morning.

When the greatest evening elongation is close to the spring equinox, Venus is visible for a maximum time after sunset.

During next month’s crescent moon, a similar display will occur, with Venus reaching maximum elongation on March 24. 

In the latter half of the year, Venus will shift to become “the morning star.”

 

 

 

 

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Updated on January 27th, 2013

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